To identify donor-related risk factors associated with graft endothelial failure and postoperative endothelial cell density (ECD) reduction after Descemet's stripping automated endothelial keratoplasty (DSAEK).This was a single-center retrospective study conducted from July 2006-December 2016. We included 584 consecutive eyes (482 patients) that underwent DSAEK for the treatment of laser iridotomy-related bullous keratopathy (192 eyes), pseudophakic bullous keratopathy (137 eyes), regraft (96 eyes), Fuchs' endothelial corneal dystrophy  and others (100 eyes). Twenty-three donor- and recipient-related risk factors potentially associated with graft failure and ECD reduction were assessed using Cox hazard models and linear mixed effect models.2  to 1,132  at 12 months and 904 (845–963) at 24 months (P < 0.001). Fifty-five eyes (9.4%) had graft endothelial failure without rejection. This failure was associated with donor pseudophakic lens status  and preoperative endothelial folds . The incidence of graft endothelial failure in non-FECD patients was significantly higher among those receiving donor grafts with a pseudophakic lens status and preoperative presence of endothelial folds (P < 0.001). Postoperative ECD loss was significantly greater in eyes with these risk factors compared to those without (P = 0.007).The median age of the patients was 73.5 years . After DSAEK, ECD decreased from 2,674 cells/mmPseudophakic status and/or presence of preoperative endothelial folds are the significant donor risk factors for endothelial failure in non-FECD patients. Corneal endothelial dysfunction is one of the leading causes of blindness among patients with corneal diseases . SelectiPrevious clinical studies have shown various risk factors, including donor and recipient factors, associated with endothelial cell density (ECD) loss and graft failure –13. HoweThis study was conducted according to the tenets of the Declaration of Helsinki, and it received approval from the Institutional Ethics Reviewer Board of Tokyo Dental College Ichikawa General Hospital (Acceptance No. I 18-19). Our Institutional Review Board waived the requirement for informed consent for this retrospective study. Patient data were anonymized before access and/or analysis.2 preoperatively. The DSAEK procedure was performed using the double-glide technique in a standardized manner , cause of death (cardiac disease/cancer/cerebrovascular accident/respiratory disease/other diseases), refrigerated body/eyes, time from death to the preservation, time from death to operation, ECD, and graft endothelial folds (none/mild/moderate). The graft endothelial fold severity grade for each patient was determined based on slit-lamp microscopic examination findings before DSAEK. Briefly, grafts without folds were defined as having “no graft folds,” “mild graft folds” were defined by the presence of graft folds limited to <25% of the area of the total cornea, and “moderate graft folds” were defined by the presence of graft folds occupying more than 25% of the area of the total cornea. Among recipient/surgical factors, we evaluated age, sex, etiologies of bullous keratopathy, lens status at DSAEK, simultaneous cataract surgery, re-bubbling, central graft thickness, and graft diameter. Thus, a total of 23 potential preoperative risk factors (15 donor-related and eight recipient-related factors) were evaluated . All domestic corneas were donated to Japanese eye banks and were transported to Tokyo Dental College Ichikawa General Hospital via CCEB. Imported corneas were prepared at an eye bank in the United States of America  and were shipped internationally by airplane. All donor corneas were preserved in a viewing storage chamber and kept in cold-storage corneal preservation medium  at a temperature of 2°-8°C. In the eye bank, the central corneal ECD of all tissues was measured using specular microscopy and slit-lamp microscopy was performed by eye bank technicians or eye doctors to evaluate transplant suitability . ECDs of all the grafts used for DSAEK in this study were more than 2,000 cells/mmd manner , 18. Brid manner . In somereported , 19. To reported . Graft sreported  that canvaluated .P < 0.05 in univariate analysis underwent proportional hazard analyses by log-log plot and Schoenfeld residuals tests and were included in multivariate Cox proportional hazard regression analysis for estimation of the independent predictors of endothelial failure in all patients. The prognostic model was prepared by combining the extracted risk factors  and recipient and surgeon (random effect). Continuous variables were included in all ECD models in continuous form but were categorized for display in tables. Missing data were not imputed. Statistical analyses for graft survival were conducted using STATA/IC 16.0 for Windows  and R version 4.3.0 for Windows  was used for ECD analysis. All reported P values were 2-sided, and values < 0.05 were considered statistically significant.To evaluate the associations between postoperative ECD changes and risk factors adjusted for the effects of patient and surgeon factors, we used linear mixed effect models with random intercepts for recipient and surgeon effect. In the univariate model, the interaction of all potential risk factors and postoperative time were analyzed. Potential risk factors from univariate models with 2 , 157 grafts (26.9%) had no endothelial folds, while 427 grafts (73.1%) had mild to moderate endothelial folds before DSAEK.In 584 eyes of 482 patients , the medP = 0.04), history of diabetes mellitus (P = 0.007), donor lens status (P < 0.001), endothelial folds (P = 0.003), and etiology (P = 0.04) were found to be statistically significant. These five variables were added to a multivariate model. Cox proportional hazard regression analysis revealed that donor lens status  and endothelial folds  were risk factors associated with endothelial failure .During the 2-year follow-up period, endothelial failure occurred in 55 eyes (9.4%). The cumulative probability of endothelial failure after DSEAK in the entire cohort was 0.94  at 1 year and 0.88  at 2 years . Among t failure . Figure 2  to 1,447  at 1 month, 1,328  at 3 months, 1,255  at 6 months, 1,132  at 12 months, and 904  at 24 months , donor lens status (P = 0.02), graft ECD (P = 0.07), endothelial folds (P = 0.04), recipient sex (P = 0.05) and etiology (P = 0.06) had statistically significant association with postoperative ECD. Multivariable models showed that the risk factors independently associated with %ECD loss included donor lens status (P < 0.001), endothelial folds (P = 0.002) and etiology (P = 0.001). When the patients were stratified based on graft risk factors , ECD after DSAEK was significantly greater in eyes receiving grafts from phakic eyes and without preoperative endothelial folds compared to those receiving grafts from pseudophakic eyes and/or with preoperative endothelial folds, in the mixed effect model adjusted with etiology  at 1 month, 415 eyes (71.1%) at 3 months, 442 eyes (75.6%) at 6 months, 454 eyes (77.7%) at 12 months, and 383 eyes (65.5%) at 24 months after DSAEK. Mean postoperative ECD was associated with postoperative time and decreased from 2,674 cells/mmWe identified donor lens status and preoperative graft endothelial folds as risk factors associated with graft endothelial failure and ECD reduction after DSAEK. Furthermore, we demonstrated that these risk factors were clinically relevant especially in non-FECD and not in FECD, since these were associated with endothelial failure after DSAEK in non-FECD eyes. Although the prognosis of endothelial keratoplasty has been reported to be poor in eyes with PBK , 10, 12 Corneal transplants are performed in 116 countries, and imported grafts are used in 70 countries . The intPrevious studies identified several factors, including lower graft ECD , 12, hisWe identified pseudophakic donor lens status as a risk factor associated with ECD reduction and graft de-compensation after DSAEK, in contrast, the recipients' lens status did not show a statistically significant difference. This may be related to the relatively short follow-up period of 2 years after DSAEK. The annual ECD reduction rate in normal eyes is 0.9%, which can increase up to 2.5% per year after cataract surgery . Kawai evs. moderate folds) in endothelial failure after DSAEK . Further studies are necessary to evaluate the association between the presence of graft folds and reduction in viable corneal endothelial cells. Other potential risk factors discussed in previous studies , donor sex (P = 0.13), history of diabetes mellitus (P = 0.09), graft ECD (P = 0.06), gender matching , re-bubbling (P = 0.18), graft thickness (P = 0.93), and graft diameter (P = 0.80). This may have reflected differences in the cohort of recipients.In the current study, the preoperative presence of graft folds was associated with endothelial failure and lower ECD after DSAEK. Previous studies have reported the existence of dead cells in donor corneal endothelium preserved in Optisol-GS and stored at a temperature between 4° and 8°C before transplantation . Corneal studies , 26, 27 This study had some limitations. First, heterogeneous etiologies, such as FECD, PBK, LIBK, and regraft, could potentially have caused bias. We found that pseudophakic donor lens status/preoperative endothelial folds were risk factors for poor prognosis of DSAEK in the non-FECD group. Further analysis that stratified the patients based on etiology for BK was attempted. DSAEK using a graft from pseudophakic donor eyes with preoperative endothelial folds showed a trend of poor prognosis in a non-FECD group, but there was no statistically significant difference for BK other than LIBK . A largeIn conclusion, grafts from pseudophakic donor eyes with preoperative endothelial folds are identified as risk factors for endothelial failure after DSAEK in recipients with non-FECD. The results of this study suggest that optimization of corneal donor tissues for patients undergoing endothelial keratoplasty is important, especially for non-FECD patients.The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.The studies involving human participants were reviewed and approved by the Institutional Ethics Reviewer Board of Tokyo Dental College Ichikawa General Hospital (Acceptance No. I 18-19). The patients/participants provided their written informed consent to participate in this study.SN and TY had full access to all the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis, study concept and design, and drafting of the manuscript. SN, TY, MH, HN, JS, and KH critical revision of the manuscript for important intellectual content. SN, TY, and HN statistical analysis. JS and SN obtained funding. JS, TY, and MH study supervision. All authors acquisition, analysis, or interpretation of data and administrative, technical, or material support.This study received funding from a Novartis Research Grant. The funder was not involved in the study design, collection, analysis, interpretation of data, the writing of this article or the decision to submit it for publication.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


When the SEGH international board released a short editorial paper back in 2019, we described an aim to increase the membership offering, whilst improving the diversity of input regionally, by scientific discipline and to ensure greater and more regular contact across the regions from 2020 onwards. Wider aspirations described in 2019 (Watts et al.  When the SEGH international board released a short editorial paper back in 2019, we described an aim to increase the membership offering, whilst improving the diversity of input regionally, by scientific discipline and to ensure greater and more regular contact across the regions from 2020 onwards. Wider aspirations described in 2019 . The ECR programme has been a growing success, gradually finding its feet with a position paper in Environmental Geochemistry and Health from this cohort to suggest the future priorities for SEGH in 2019 :We have made good progress on the first point, in that a significant proportion of presentations since 2019 was given by ECRs (~ 25–66%). This has been helped by the switch to online delivery, with the sessions in the SEGH Live 2 event chaired by African ECRs. The ECRs have not progressed to a special issue in EGAH, but it is hoped that the ongoing writing workshop for African ECRs will result in a series of papers for submission as a special issue by mid-2022. The ECRs are recognised within each of the presentations, and for the larger meetings with prizes comprising of book tokens provided by SpringerNature up to the value of $250 to first prize and $150 to second prize winners. SpringerNature initiated a process in 2020 to identify papers submitted to EGAH by ECRs and to provide an annual award for the best paper, for which the SEGH international board unanimously voted for Daniel E. González-Santamaría . It may be that the lower number of business colleagues is not a problem and reflects the general involvement in society activities due to differing priorities. However, SEGH should still try to engage with the business community, for similar reasons to targeting the UN SDGs, in maintaining relevance to real-life applications, for example, engagement with professional consultants  working with the mining, energy, waste or agricultural sectors.The official SEGH journal Environmental Geochemistry and Health (EGAH) has continued to grow in success, with the number of papers submitted increased to 1123 in 2020 and 955 to November 2021 from 610 in 2018, with a 40% acceptance rate, on the back of a rapid increase from 400 + in 2016. The five-year impact factor as one measure of success increased from 3.252 in 2018 to 4.61 for 2020.As part of the 50th anniversary year of SEGH, a special issue in EGAH is underway comprising of short communication papers for topical discussions, reviews of progress across the multidisciplinary topics within the SEGH community and horizon scanning for future priorities. The papers were drawn from the international board and in particular involving the Fellows of SEGH (FSEGH) established for community members with substantial contributions, who were also connected with ECRs to provide mentorship through involvement in some of the papers. We received nine papers which are in the final stages of review, with a partial release of papers online underway (Davies et al., A writing workshop started in July 2021 with 56 trainees from across Africa, with training in earnest since September 2021 through to March 2022 funded by the British Academy. Training delivered by Zoom to trainees from Djibouti, Kenya, Malawi, Niger, Nigeria, Senegal, Zambia in September and November 2021 comprised formal lectures in writing skills from the Editor in Chief of the journals Chemistry Africa and Environmental Geochemistry and Health, along with training regarding uncertainty in measurements. Each of the delegates was led through a process of writing a blog for the SEGH website to practice writing and peer review skills. This cohort will have differing routes to developing their writing skills via short communication or investigative papers in each of the journals, alongside writing skills necessary for communication or in drafting proposals. It is highly likely that this kind of support can continue to be delivered to ECRs on a wider regional basis in the future, using the modified SEGH website platform to host all recorded online presentations and training lectures, free to access, with continued additions to the online resource.th anniversary year.Hybrid meetings are planned for 2022, to celebrate a 50 + 1-year anniversary of SEGH, with an unfortunate delay in a physical celebration akin to the delayed Tokyo Olympics. It is hoped that physical meetings in Kenya and China may be supplemented with international delegates via a hybrid online platform. With the transition to net zero and prospective cuts in carbon emissions, in particular for international travel likely to be imposed, a hybrid format for conferences will be a responsible approach for a society with interests in the protection and investigation of the environment and health. Innovative approaches that continue to evolve the SEGH community interaction may well see groups of delegates within national borders connected virtually to try and boost the essential social interaction that is often missing from the pure online platforms. In any case, the adaptations made during the COVID-19 pandemic will serve SEGH well as the society develops beyond its 50We will enter 2022 with a new President and a broader base for the international SEGH board and wider membership. Michael Watts will handover the reins after two 2-year terms following an election of a new candidate by the members. The aspirations presented in 2019 are still relevant for the foreseeable future, but will need to continue to operate within the context of SEGH working to the constraints or exploiting the opportunities arising from the COVID-19 pandemic and presented by global collaboration towards a net zero future for carbon emissions. The current international board was elected through to 2023 providing organisational resilience globally to support the next President, along with formal organisational roles to support the administration of SEGH. The board wish the new President well in guiding SEGH forward to new opportunities.


Significant correlations were observed between pain and stiffness of AT , but not in the PFT (P = 0.557). Optimal cut-off stiffness was AT (452 kPa) in the relaxed ankle position. The plantar fascia of patients with PF was significantly thicker than that of the controls (P < 0.001). Findings from the present study demonstrate that tendon stiffness is a good indicator of the clinical situation of patients with PF. Monitoring passive tendon stiffness may provide additional information to assess severity of the condition and guide therapeutic. The treatment programs for PF should also be tailored to the distal AT, as conventional therapy might not be targeted to tight tendons.The elastic properties of the Achilles tendon (AT) are altered in local injury or other diseases and in response to changes in mechanical load. Recently, elastography has been used to evaluate variations in tendon elastic properties, mainly among healthy individuals or athletes. Therefore, this study evaluated the biomechanical changes in ATs in individuals with and without plantar fasciitis (PF). The purposes were as follows: (1) to evaluate the passive stiffness of three regions of the AT which defined as 0 (AT0 cm), 3 (AT3 cm), and 6 cm (AT6 cm) above the calcaneal tuberosity in participants with and without PF, (2) to investigate the interplay between the passive stiffness in patients with PF and pain, (3) to detect optimal cut-off points of stiffness of the AT in assessing individuals with chronic PF, and (4) to determine the correlation between the plantar fascia thickness (PFT) and pain. This cross-sectional study included 40 participants (mean age = 51 ± 13 years). When the ankle was in a relaxed position, patients with PF experienced increased passive stiffness in AT0 cm ( Plantar fasciitis (PF) is a common disorder of the foot, with an incidence of approximately 1% . AlthougThe AT is one of the strongest tendons in the body. It is the elastic structure that connects the triceps surae muscle to the plantar fascia, serves as the main plantarflexing mechanism of the ankle joint, and transmits force based on the amount of stretch endured . Tendon Shear wave elastography (SWE) is an ultrasonography elastography technology known for fast, accurate, and non-invasive evaluation of tissue stiffness . It geneTherefore, we used Young’s modulus measurements as an index of tendon elastic properties. The purposes of this study were fourfold: (1) to evaluate the passive stiffness of different regions of the AT in participants with and without PF, (2) to investigate the interplay between the passive stiffness in patients with PF and pain, (3) to detect optimal cut-off points of stiffness of the AT to assess chronic PF, and (4) to determine the correlation between the plantar fascia thickness (PFT) and pain.The study was approved by the Human Subject Ethics Committee of the Luoyang Orthopaedic Hospital of Henan Province (NO: KY2019-001-01). The experimental procedures were explained to each participant prior to participation. All participants provided written informed consent prior to the experiment, and all study procedures adhered to the principles of the Declaration of Helsinki.This study comprised of 40 participants, 20 patients with PF and 20 asymptomatic, aged 32–69 years . The inclusion criteria for PF were as follows: (1) plantar heel tenderness, (2) pain symptoms longer than 6 months, (3) morning pain with the first few steps out of bed, (4) pain score ≥ 3/10 using a visual analog scale (VAS), and (5) the more painful leg of patients with bilateral PF was included . The excBasic information about the participants was recorded, including age, sex, height, weight, BMI, VAS score, and duration of pain.The Young’s modulus of the AT was quantified using an ultrasound shear wave elastography system  with a 40 mm linear array transducer . The settings were set as follows : the iniParticipants were placed in a prone position with their feet fully relaxed and placed over the edge of the examination bed. The Young’s modulus of the AT was examined on the painful leg when the ankle was passively “relaxed” or neutrally placed (90°). Leg-matched asymptomatic participants were examined as controls. It is noteworthy that for the relaxed position of the ankle participants took what they perceived to be a “relaxed” ankle position, that is, the feet were maintained in a naturally hanging position, while the neutral (90°) position was fixed by a customized and movable ankle foot orthosis. The angle of ankle of PF group included as the angle of “relaxed” position was tested by a manual goniometer , and it was used as the relaxation angle of age-matched and gender matched asymptomatic group. As AT has unique twisted structure and anatomical composition, there are some differences in biomechanical characteristics among different positions of AT . AccordiAs proposed previously , a largeParticipants were placed in the prone position as mentioned above, and a 40 mm linear array transducer  was used to measure the sagittal plantar fascia thickness (PFT). The transducer was placed over the surface closest to the medial foot, and then the PFT was measured at the anterior margin of the calcaneus and stored for offline analyses .∗Power 3.0.10 software was used to determine the required number of participants. According to the results of a previous pilot study, an estimated effect size of 0.3, was set as 0.05, and the power was 0.85; therefore, the total sample size was 30 participants . To avoid issues due to dropouts or missing data, the number was increased to 40 .Gp > 0.05). Independent t-tests were performed for demographic data, such as age, weight, and height. Multivariate analysis of covariance (MANCOVA) tests were performed to compare the Young’s modulus of the ATs  at different ankle angles  on the painful side of patients with PF and the dominant side of healthy controls, with variables with significant group differences as covariates. When the level of significance was reached, post hoc analyses were performed using univariate analysis of covariance tests. Pearson correlation analysis (r) was used to examine the correlation among the main variables (Young’s modulus of ATs), duration of pain and pain, and to examine the correlation between secondary variables (PFT) and pain. Receiver operating characteristic (ROC) curve analysis was performed to calculate the cut-off point of the elastic properties of the ATs that displayed significant group differences. For all tests, statistical significance was set at p < 0.05.The data were analyzed using SPSS version 22.0 software  and expressed as mean ± standard deviation. The normality of distributions was assessed using the Shapiro-Wilk test. Our data were normally distributed . However, the PFT of the PF group (0.5 ± 0.8 cm) was significantly thicker than that of the healthy group (0.3 ± 0.1 cm) . The angle of “relaxed” position of the ankle joint was 23 ± 2 degrees, which was significant difference with the neutral (90°) position (P < 0.001).Twenty-two participants reported heel pain at the medial plantar and clinical diagnosis suggested the presence of PF, and two candidates declined to participate. Twenty-three asymptomatic participants were assessed for study eligibility, and three did not meet the inclusion criteria. The age, height, weight, and BMI in both groups, VAS score, and duration of heel pain for symptomatic participants are summarized in P = 0.006; 10 ± 14%, p = 0.003, respectively). There was no significant difference at the AT6 cm. No between-group differences were observed in the three regions of AT measured in the neutral position (p > 0.05).The mean elastic property values of the AT in the PF and healthy groups are summarized in r = 0.489, p = 0.029), the Young’s modulus of AT3 cm , and the Young’s modulus of AT6 cm . There was no significant correlation between pain score and elastic properties of the ATs in the neutral position (p > 0.05). In addition, there was no significant correlation between the pain score and PFT .The correlations among PFT, elastic properties of ATs, and pain scores are showed in P-values > 0.05).The correlations among elastic properties of ATs and the duration of heel pain are summarized in p = 0.006), and that of AT3 cm was 0.755 (p = 0.006). Youden’s index revealed that the Young’s modulus of AT  at the relaxed position of the ankle in assessing individuals at risk for chronic PF. The AUCs for the rest of the tested regions were not statistically significant and were included in the neutral position.The optimal cut-off point for the elastic properties of ATs for assessing individuals with chronic PF was calculated using ROC curves . When coTaking advantage of SWE, this study evaluated the biomechanical changes in the AT of individuals with and without PF. We observed that the PF group exhibited higher distal AT (AT0 cm and AT3 cm) stiffness in the relaxed position of the ankle. Moreover, significant correlations were detected between pain score and the elastic properties of AT in the relaxed position of the ankle, and no significant correlation between ATs stiffness and the duration of heel pain. Furthermore, the optimal cut-off points of the elastic properties of ATs were determined in the relaxed position of the ankle, which may help to assess individuals with chronic PF.This is the first study to compare the elastic properties of ATs between individuals with PF and healthy controls. As proposed in a recent study, the measurement of passive elastic properties could be advocated as a preventive, diagnostic, and prognostic instrument in individuals with PF. Our results indicate that when the ankle was in a relaxed position, the passive elastic properties of the AT0 cm and AT3 cm of patients with PF were stiffer than those of healthy individuals, but this was not observed for the AT6 cm. Interestingly, there were no significant differences in the passive elastic properties of the ATs between the PF and healthy groups when the ankle was in a neutral position. These findings could be interpreted by the fasciopathy patterns of the histological alterations of PF. In the degenerative processes, matrix degradation, fibroblastic hypertrophy, and collagen breakdown result in a lack of plantar fascia stiffness and contribute to PF . The stiOur results also demonstrated that the percentage change in the AT0 cm (11.50%) stiffness of the participants with PF was significantly higher than that of AT3 cm (9.23%). The disparity in different regions of AT may be due to the different regions of AT experiencing different strains and compressive loads and exhibit distinct histological alterations in PF . For exaWe observed significant correlations between pain and AT stiffness when the ankle was in a relaxed position. This means that the increased the stiffness of the AT is associated with greater intensity of pain. Our results demonstrate that the plantar fascia is significantly thicker among individuals with PF than healthy participants (0.5 ± 0.8 cm vs. 0.3 ± 0.1 cm), and there was no correlation between PFT and pain, indicating that PFT is not a good clinical indicator of treatment response. The findings of this study are consistent with recent reports. For example, This study also found that there was no significant correlation between ATs stiffness and the duration of heel pain. Our results are similar to previous studies. As discussed above, the increase in the passive elastic properties of the AT may be due to an overload of the plantar fascia associated with sports participation. Preventive methods include a variety of stretching methods, including AT, plantar fascia, or silicone insoles. Ultrasound measurements, using both the SWE and grayscale to assess the morphology of the plantar fascia and the AT stiffness, may provide additional information to assess severity of the condition and guide therapeutic interventions in patients with PF. Given this, we calculated the initial cut-off stiffness of the AT  at the relaxed position of the ankle to assess chronic PF. This also suggests that individuals with a passive stiffness of the AT greater than 452 kPa may have a higher risk of plantar fascia injury. It is worth noting that the results of ROC curves showed that AUC has relatively low specificity for patients with chronic PF. This may be related to the different activity patterns and exercise intensity between the PF group and healthy group. According to previous studies, the more activity or exercise intensity, the greater the stiffness of AT .The limitations of this study are that electromyography was not used to monitor the gastrocnemius muscle and soleus muscle activity during SWE measures and ensure these muscles were no firing. However, all participants were verbally instructed to stay relaxed, and no signs of muscle contraction were observed on the gray-scale image. Based on this, we are confident that while their lower limb were fully supported, patients or subjects remained in a passive state during passive dorsiflexion. In addition, we did not estimate the correlation between AT stiffness and plantar fascia stiffness in patients with PF. Furthermore, we did not use longitudinal follow-up to observe how AT stiffness and plantar fascia thickness changed during treatment, and whether they were affected by interventions such as stretching. Further studies should be conducted to investigate these factors.The present study is the first to assess the relationship between heel pain severity and AT stiffness in patients with PF. Patients with PF had significantly greater AT stiffness than healthy participants. The increase in passive stiffness of distal AT is associated with pain, and initial cut-off points of distal AT stiffness at the ankle relaxed position may provide additional information to assess severity of the condition and guide therapeutic. The treatment programs for PF should also be tailored to the distal AT, as conventional therapy might not be targeted to tight tendons.reha_jp@163.com.The data analyzed in this study is subject to the following licenses/restrictions: Datasets are available on request. Requests to access these datasets should be directed to The studies involving human participants were reviewed and approved by the Human Subject Ethics Committee of the Luoyang Orthopedic Hospital of Henan Province. The patients/participants provided their written informed consent to participate in this study.WP and ZZ designed the experiments. JZ and YL carried out the experiments and collection data. WP and JZ analyzed the experimental results and drafted the manuscript. All authors contributed to manuscript revision, read, and approved the submitted version.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


The various blends of the bio-composite films decayed by over 50% of the original mass after 12 days of complete burial in soil. Based on the results obtained in this study, the addition of keratin to starch bio-composite showed remarkable improvement in mechanical properties, such as tensile strength and surface smoothness. The bio-composite film exhibited appropriate stability in water, although future study should be carried out to evaluate its thermal stability. Nonetheless, the fabricated keratin-starch bio-composite showed desirable characteristics that could be optimized for industrial applications.The disposal of chicken feather through burning or burying is not environmentally compliant due to the accompanying release of greenhouse gas and underground water contamination. Thus, the transformation of this bio-waste into a bio-composite film is considered not only a sustainable strategy for disposal of this solid wastes but also an attractive alternative to developing an efficient nanostructured biomaterial from renewable bio resource. In the present study keratin extracted from chicken feather waste in combination with ginger starch were fabricated into a bio-composite film. The fabricated bio-composite films were characterized, using different analytical techniques. The physicochemical characteristics of ginger starch showed a moisture content of 33.8%, pH of 6.21, amylose and amylopectin contents of 39.1% and 60.9%, respectively. The hydration capacity of the starch was 132.2% while its gelatinization temperature was 65.7 °C. Physical attributes of the bio-composite film, such as surface smoothness and tensile strength increased significantly ( No doubt, the impacts of climate change is becoming more devastating with each passing year. Natural disasters, such as flooding, fire outbreaks, drought, extreme heat etc. are unforeseen consequences of climate change with devastating consequences. Global efforts aimed at reducing climate change though promising are insufficient at the moment. Thus, research efforts focusing on promoting low-cost ecofriendly approaches to meeting human needs should be encouraged2, there is a renewed efforts aimed at promoting the use of bio-composite from renewable raw materials as alternative to single use, non-biogradable plastics. Bio-composites are evolving as a sustainable substitute to petroleum-based composites especially in food packaging applications. Hence, there is renewed research attention focusing on the fabrication of composite materials from biopolymers. Natural polymers such as proteins and polysaccharides have been reported to exhibit film-forming properties5. Unlike synthetic or hydrocarbon-based polymers, bio-based polymers are edible, ecofriendly, easily affordable and available. The development of bio-based films or coatings from renewable sources, such as polysaccharides , proteins , lipids has attracted considerable research efforts in recent times9. Protein-based biopolymers are characterized by their safety, biodegradability and biocompatibility. Recently, Tesfaye et al.3 demonstrated the production of keratin-based biofilm from chicken feather waste and starch extracted from avocado seeds.Consequent upon the growing environmental concerns on disposing packaging materials after use12. That is, the contribution of chicken feather waste to the total solid waste is substantial. Thus, management strategies aimed at mitigating the environmental consequences of chicken feather waste is urgently required. By focusing on the physical and chemical structures and properties of feather keratin, researchers might be able to develop some economically feasible applications for the increasingly large amount of chicken feather waste generated daily14. Functional keratin has been extracted from chicken feather using various methods ranging from chemical16, enzymatic17 and with ionic solutions18. The properties of the extracted keratin has been shown to be a function of the method of extraction method. The synthesis of keratin microparticles from chicken feathers using sodium hydroxide was demonstrated by Sharma et al. and more recently, keratin solution was prepared from chicken feather for the fabrication of keratin-based bio-plastic using chemical method by Alashwal et al.15.Protein processing industries including slaughter house, meat packing, leather processing plant etc. generate a huge amount of keratin containing wastes. Of these industries, the poultry slaughter industries take the lead in that approximately seven billion tons of chicken feather waste is added to the global solid waste biomass yearly19. Starch is considered a sustainable bio-resource for various industrial applications due to its abundance and low cost. More so, unlike other natural polymers such as cellulose and gums, starch can be obtained in pure form using relatively easy techniques20. Maize remains the main botanical source of starch accounting for about 80% starch production in the global market. However, considering the economic implication of maize utilization in terms of food security, the evaluation of new sources of starch for industrial product utilization is attracting renewed interest21. Ginger  is a member of the Zingiberaceae. It is an herbaceous perennial root crop cultivated extensively worldwide. The underground stem or rhizome with its characteristic pungent aromatic smell is consumed as a delicacy, medicine or spice. However, with its high starch content (40–59% dry weight), it has been identified as a promising biomass for the production of starch23.The choice of starch for an industrial product depends on its availability as well as the physicochemical properties25. However, the quality attributes of bio-based plastics could be considerably improved through the combination of several other biopolymers in the form of composites or blends. In recent times, there has been renewed research efforts focusing on obtaining the best combination of materials mixed for maximum efficiency. The suitability of bio-polymeric films in food packaging depends largely on the polymers as well as other materials used as additives to improve their functional properties. Starch, owing to its low-cost, availability and biodegradability is one of the most studied biopolymer with immense potential for conversion into thermoplastic starch (TPS) for food packaging. However, the high hydrophilicity of starch polymers often restricts its stability and processability as a bioresource for bio-composite film. Therefore, the combination of starch with hydrophobic biopolymers such as keratin is desirable to enhance its resistance against water as well as improved mechanical properties of the bio-composite film25. The present study therefore is focused on the transformation of waste keratin extracted from chicken feather waste and ginger root starch into a novel nanocomposite biofilm.In relation to petroleum-based plastics as packaging materials in food industries, bio-based plastics exhibit lower mechanical and barrier properties but possess higher permeability to gases and water vapourThis study does not require any formal consent as it does not include any human participation or animal experimentation. All the experiment has been done in accordance with relevant institutional, national, and international guidelines/legislation.Chicken feather: Chicken feather was obtained from the animal processing unit at Landmark University Commercial Farm, Omu-Aran, Kwara State, Nigeria.Ginger: Ginger roots was purchased from Omu-Aran market and transported fresh in polythene bag to Biochemistry Laboratory.Chicken feather and keratin extraction: Chicken feather was obtained from the animal processing unit at Landmark University Commercial Farms. The white coloured feather wastes were free of blood and grease by washing severally with detergent and then rinsed several times with tap water to remove every trace of the detergent. The washed feathers were spread on a clean dry white board to remove any extraneous tissues such as skin, intestine, beak, etc. Thereafter, the feathers were disinfected by soaking in 0.5% hypochlorite solution, sodium thiosulphate was added to neutralize the hypochlorite before being rinsed severally with distilled water before being dried to constant weight at 60 °C in a forced-air oven. The dried feathers were cut into small pieces and milled into powder, using a mechanical grinder. One thousand gram (1000 g) of the powdered feather was soaked in acetone  overnight, filtered and allowed to air-dry at 27 °C. Keratin was extracted from the powdered feather following a combine methods of Akpor et al.26 and Tesfaye et al.3. Fifty gram (50 g) feather powder was dissolved in 150 mL of 0.1 M sodium hydroxide solution, mixed thoroughly and then placed in an orbital shaker at 27 °C for 8 h. The resulting solution was filtered through a muslin cloth. The pH of the dissolved feather solution was adjusted to 2.4 using 10% trichloroacetic acid and the precipitated keratin filtered through a muslin cloth, washed severally in distilled water and then freeze-dried. The dried keratin was pulverized using a mechanical grinder, sieved through a 50 µm sieve and then stored at 4 °C until required for further analysis.23. Freshly purchased ginger roots were neatly peeled, washed with copious water, sliced into small pieces and soaked in 1% sodium metabisulphite solution to prevent oxidative browning. Afterward, the chopped ginger roots were milled into a slurry using an electric blender. The starch slurry was then dispersed in a large volume of 1% sodium metabisulphite solution before been filtered using muslin cloth. The obtained filtrate was centrifuged for 15 min at 3000 rpm after which the supernatant was carefully decanted and the mucilage scraped off. The process was repeated trice until the starch was obtained in a pure form. The extracted starch was oven-dried to constant weight at 30 °C, weighed and then stored at 4 °C, until required for further analysis.Starch was extracted from ginger rhizome according to the method of Afolayan et al.3 was followed with little modifications. Briefly, a 5% starch solution was prepared and gelatinized by heating on an electric heater at 70 °C under constant stirring. Keratin solution was made by adding 5 g keratin powder in 100 mL of 0.1 M NaOH and heated in an electric heater at 70 °C for 20 min with constant stirring. Different blends of starch and keratin solutions were then prepared as follow: 20:0 (control), 20:1, 20:3 and 20:5 (starch:keratin v/v). To each starch-keratin blend 1 mL of glycerol was added as plasticizer, after which the mixture was heated at 70 °C on an electric heater for 10 min, with vigorous stirring before being poured into a glass petri dish and oven-dried at 50 °C for 24 h. The resulting film was carefully peeled and kept in a cool dried carton at 25 °C before further analysis.In the preparation of the keratin-starch bio-composite film, the method described by Tesfaye et al.23. Ginger starch (0.1 g) was added to 10 ml of distilled water and heated at 50 °C for 30 min in a water bath with continuous shaking. The resulting slurry was centrifuged at 2000 rpm for 15 min after which the supernatant was carefully decanted and the resulting starch paste weighed. Thereafter, the swelling power was estimated from Eq.  starch dispersion was prepared with continuous shaking in a water bath at 50 °C for 5 min. Having allowed the starch gel to cool to about 25 °C, the pH determined using a pH meter with a glass electrode after standardizing with 4 and 7 pH buffers.The pH was determined using a British Standard Institution (BSI 757) as described by Taheri et al.28. One gram (1 g) starch sample was dispersed in 10 mL distilled water and stirred vigorously. The starch solution was placed on a hot plate and heated with continuous stirring. With the aid of a suspended thermometer, the gelatinization temperature was then estimated.The gelatinization temperature was determined following the method described by Nwokocha et al.In order to ascertain the effect of sodium hydroxide used for the hydrolysis of chicken feather on the isolated keratin, FTIR analysis of both raw feather powder and the keratin obtained in this study. This was done using an FTIR Spectrometer .The bio-composite film thickness was estimated with the aid of a digital MDC-MX 923 µm . For each bio-composite film, 10 random points were sampled and measurements were taken and the mean values calculated.29 method.The degree of transparency or opaqueness of the bio-composite film with the aid of a UV–visible spectrophotometer  at 560 nm. The measurement was done following Santacruz et al.The moisture content of the bio-composite film was determined by drying the bio-composite film to constant weight in a forced air oven at 100 °C. The moisture content was then calculated using Eq. :3\docume30, with the aid of a Universal Testing Machine  according to ASTM standard D882. In measuring the tensile strength, a 1.0 kN load was applied at 10 mm/mim constant at 27 °C. From the data obtained, tensile strength and elongation at break were calculated.The tensile strength of the bio-composite film was determined according to the method of Rahman and Jamalulail31. A weighed amount of the keratin-starch bio-composite films was completely immersed in water for a period of 12 da and at every three-day interval, the bio-composite film was exhumed and weighed.The solubility of the keratin-starch bio-composite film in water was determined according to the method of Pavin et al.31. In this study, a weighed amount of the keratin-starch bio-composite films was vertically buried at 3–5 cm depth inside the soil to ensure aerobic degradation conditions at 25 ± 2 °C and 35–50% relative humidity for a period of 12 days and at every three-day interval, the bio-composite film was exhumed, washed with water, dried to constant weight and weighed.The degradability test of the keratin-starch bio-composite films in soil was studied, following the method of Pavin et al.The morphological analysis of keratin, ginger starch, and keratin-starch bio-composite film was carried out with a field emission gun scanning electron microscope (SEM) . The sample was placed on a gold coated stub with the aid of a diode sputter coater. The crystalline phase evaluation was carried out with the aid of a benchtop XRD analyzer , equipped with a diffracted beam monochromator and a copper target X-ray tube operated at 40 kV and 30 mA.P < 0.05.The experimental set up was carried out in triplicate and the results expressed as mean ± SD. The results were statistically analyzed using two-way analysis of variance (ANOVA) followed by Turkey multiple range test. Charts were drawn using GraphPad prism 8.0 software . Significant level was set at The physicochemical characteristics of ginger starch showed a moisture content of 33.8%, pH of 6.2, amylose and amylopectin contents of 39.1% and 60.9%, respectively. The hydration capacity of the starch was 132.2% while its gelatinization temperature was 65.7 °C  higher than 20:5 bio-composite (Table p < 0.05) with increasing keratin concentration in the film.The fabricated bio-composite films obtained from starch, and a combination of starch and different volumes of keratin with glycerol as plasticizer is shown in Fig. p > 0.05)  had significantly lower solubility in water, when compared to the starch only (20:0) bio-film. The solubility of the keratin-based bio-composite  decreased with increasing keratin content though the observed decreases were insignificant (05) Fig. .Figure 4The various blends of the bio-composite films decayed by over 50% of the original mass after 12 d of complete burial in the soil. No appreciable difference was however observed in the degree of degradability between the various blends on day 12  reported by Praveen et al.35. The amylose content (39.1%) of ginger starch as revealed in this study is high compared to values obtained for wheat (25.6%)36; potato (29.3%), cassava (23.7%), and Dioscorea (26.3%)37. However, our result agrees closely with that obtained for ginger (34.0%) by Braga et al.38. Turmeric had been demonstrated to contain amylose content as high as 48%38. The amylose content of starch contributes significantly to its physicochemical and functional characteristics. Studies have shown that the amount of amylose present within a particular crop could vary even within the same botanical species due geographical and cultural variations39. Amylose unlike amylopectin is anhydrous hence impede the swelling and solubility of starch granules. The anhydrous nature of amylose offers excellent advantage in industrial application of starch in the fabrication of very strong, colourless bio-composite films40. Starches with amylose content above 30% are known to show a slight deformation in their granule appearance. The interactions within the polymeric linkages of starch determine its solubility and swelling capacity41. These interactions in turn is a function of the ratio of amylose to amylopectin42. The lower the amylose to amylopectin ratio, the greater is the swelling capacity of starch39. Starches such as ginger starch with high amylose content as demonstrated in this study usually exhibit low swelling and solubility capacity. The high amylose of ginger starch (> 30%) contributes significantly to the mechanical properties of bio-composite films. The considerably high amylose content of ginger starch in this study also contributes to its relatively high gelatinization temperature. Studies have shown that potato starch, wheat starch, and cassava starch with low amylose level exhibit a relatively low gelatinization temperatures of 57–58°C43. It is often argued that the longer branch chains in high-amylose starches is responsible for their characteristically high gelatinization temperatures. Gelatinization is a requisite process which disrupts the crystalline structure of starch as a means of facilitating good cross-linking reactions in bio-composite formation.The percentage moisture content of ginger starch as demonstrated in this study is considerably high and poses a great threat in terms of its shelf life3 on the production of bio-composite film from avocado pear kernel and keratin. The inclusion of keratin in the biofilms was also observed to enhance the toughness, in terms of tensile strength, of the films in addition to glycerol. This could be due to the formation of intermolecular bonds/interactions between the hydroxyl groups present in starch and the functional groups (carboxyl and amino groups) present in keratin amino acids. Thus, the keratin-based biofilms had higher tensile strength and exhibited higher elongation at break than the one containing ginger starch and glycerol only.The present study demonstrated the successful fabrication of thin, homogenous, yellow flexible films from varying combinations of ginger starch and chicken feather keratin. The colour variation from white to yellow as a function of increasing keratin content led to reduction in the degree of transparency of the bio-composite films. This gives an indication that keratin reduces the transparency of bio-composite film owing to the increasing solid particles in the filmogenic solution. Composites with high degree of opacity have been shown to exhibit high UV-barrier property, a desirable attribute in food packaging materials. This observation concurs with the report of Tesfaye et al.45. The inclusion of keratin in the fabricated bio-composites in this study led to remarkable reduction in moisture content. This suggests enhanced shelf life, as a result of low microbial activity, of the bio-composite film and reduced cost implication with regard to transportation. The interaction affinity of a biofilm with an aqueous environment such as obtainable within a cellular milieu is determined by its solubility. Though the utilization of a bio-composite film in food packaging only requires partial solubility in water in order to not to compromise the integrity of packed products, the solubility of certain products before consumption is beneficial. From the present study, it was observed that keratin inclusion resulted in remarkable decrease in solubility. The reduction in solubility as a consequence of keratin could be attributed to the presence of hydrophobic amino acids within the keratin matrix46. It is our submission that the potential reduction in solubility of bio-composite film as a result of keratin could be beneficial in contributing to their stability.The moisture level in the various blends of keratin-starch bio-composite films ranged between 5.5 and 19.0%. The moisture absorption capacity of bio-composites is of great significance with regard to their processing, packaging, transportation, and shelve life. During processing, moisture content of products could affect the intra and intermolecular associations within and/or between molecules present in such products thereby contributing its final mass or volume as well impact on its durability. Products with high moisture content most often tend to be heavier hence high transportation cost and are also highly susceptible to rapid deteriorationThe results of the SEM images evidently showed that the morphological appearance of keratin-starch bio-composites greatly depends on their chemical composition. Film attributes, such as surface morphology and texture are influenced by the ratio of the keratin and starch solutions. Contrary to reports by some authors, we observed that the degree of smoothness of the keratin-starch bio-composite film depends on the keratin content and not starch. From the data obtained from the X-ray difractograms, it could be observed that the XRD patterns of ginger starch showing different crystallinity peaks, completely disappeared, especially from the 20:3 keratin-starch bio-composite film. This is indicative of a perfect dispersion of the starch granules with the keratin fibres showing the extent of intercalation or cross linking in the bio-composite film.47.Data obtained from the degradation of the bio-composite fil in soil was impressive. The loss of over 50% mass observed in the keratin-starch bio-composite film after 12 ds is significant, given the challenge in chicken feather waste disposal. The soil contain a myriad of microflora consisting of bacteria and fungi. This microbial population produce different types of keratinases that act synergistically together in the degradation processThese study demonstrated the successful fabrication of a keratin-starch bio-composite film from chicken feather wastes and ginger starch. The addition of keratin to starch-based composite was observed to enhance the suitability of bio-composite for food packaging through improved quality attributes including reductions in moisture content, opacity or transparency, as well water solubility of the bio-composite films. It also showed desirable mechanical properties such as high tensile strength and elongation at break, thus contributing to its stability. The remarkable degradability of the bio-composite film is a testament of its environmental friendliness. Overall, the keratin-starch bio-composite showed comparable qualities to the non- degradable polymers. Therefore, it could offer a viable, eco-friendly and sustainable solution to solid waste accumulation in the environment.


OBJECTIVES/GOALS: To identify possible failures that could occur in the delivery of an evidence-based parenting program for mothers with substance use disorders (SUD) through existing home-visiting services, and to develop solutions to the most significant failures. METHODS/STUDY POPULATION: Using failure modes and effects analysis (FMEA) methodology, we conducted two 2-hour advisory panel discussions with 15 people from a variety of disciplines and life experiences related to SUDs. The intervention delivery process included five steps: (1) Recruitment, (2) Screening, (3) Matching, (4) Enrollment in person, and (5) Intervention delivery. Participants collectively determined possible failures, causes, and consequences. Participants then agreed on three scores  for the likelihood of occurrence, detection, and severity of the failure, with 10 being the highest likelihood, difficulty detecting, or severity. A risk priority number (RPN) was calculated as the product of the 3 scores . The group then identified possible solutions for failures with higher RPNs. RESULTS/ANTICIPATED RESULTS: For each step in the process we identified the following number of failure nodes and RPN scores: (1) recruitment: 13 failures; RPN = 800, (2) screening: 102 failures; RPN = 10, (3) matching: 4 failures: RPN = 490, (4) enrollment: 6 failures; RPN = 80, (5) delivery: 11 failures; RPN = 80. The most critical failures related to recruitment and were perceived as being caused by potential development of mistrust in the community. Participants strongly encouraged the use of “strengths-based language,” clear referral plans for mothers that did not qualify, and inclusion of mothers that did not have custody of their children. These findings resulted in changes to the screening script, enrollment procedures, and inclusion criterial for the program. DISCUSSION/SIGNIFICANCE OF IMPACT: FMEA methodology was particularly effective in identifying possible failures for the integration of an evidence-based parenting program into existing home-visiting services as they related to the psychological safety of mothers with SUDs. The process resulted in direct changes to procedures for the anticipated program integration and study.


Background and Objectives: The aim of the present study was to compare the impact of an incremental exercise test on muscle stiffness in the rectus femoris (RF), vastus lateralis (VL), biceps femoris (BF), and gastrocnemius (GL) among road cyclists of three performance levels. Materials and Methods: The study group consisted of 35 cyclists grouped according to their performance level; elite , sub-elite , and recreational . Passive muscle stiffness was assessed using myometry before and after an incremental exercise test. Results: There was a significant correlation between time and category in the vastus lateralis with stiffness increases in the sub-elite  and elite groups , but not in the recreational group (p = 0.085). Stiffness increased over time in the knee extensors , but no changes were observed in the knee flexors . There were no baseline differences among the categories in any muscle. Conclusions: Although the performance level affected VL stiffness after an incremental exercise test, no differences in passive stiffness were observed among the main muscles implicated in pedaling in a resting state. Future research should assess whether this marker could be used to differentiate cyclists of varying fitness levels and its potential applicability for the monitoring of training load. Among t fitness . Other p fitness . The mus fitness . The rel cyclist .Among the mechanical characteristics of the muscle, stiffness provides information regarding its intrinsic property and post-effort response; furthermore, it is one of the main parameters that characterizes the viscoelastic properties of the myofascial complex . A propeCurrent literature establishes different conclusions regarding stiffness levels ,10,11,12Since road cycling is an endurance sport with no impact and in which power is applied to the pedals, the lower limb muscle stiffness of cyclists might differ from other endurance disciplines. To the authors’ knowledge, only four previous studies have analyzed road cycling muscle stiffness with non-invasive tools ,16,17,18®  is a non-invasive tool that allows for the measurement of passive muscle stiffness through short oscillatory impulses [R2 = 0.95) [The active and passive measurement of muscle stiffness is normally a complex procedure as it requires either muscular biopsies or repeated maximal isometric contractions . Both meimpulses  that areimpulses . Previou = 0.95) ,21 and h = 0.95) , hamstri = 0.95) , and gas = 0.95) . Klich e = 0.95) .It is accepted that both fatigue and performance level of the athlete can influence the changes in muscle stiffness ,18,20. GThirty-five participants completed this cross-sectional study. The same order was followed during each individual assessment: anthropometry, evaluation of passive muscle stiffness (stiffness pre), incremental exercise test, and assessment of passive muscle stiffness after the incremental exercise test (stiffness post) see . In addiAssessment points placed at VL: 2/3 on the line from the anterior spina iliaca to the lateral side of the patella, RF: 50% on the line from the anterior spina iliaca superior to the superior part of the patella, BF: 50% on the line between the ischial tuberosity and the lateral epicondyle of the tibia, and GL:1/3 of the line between the head of the heel .F) of 0.4, an α level of 0.05, and a power (1−β) of 0.95. This procedure returned a minimum number of 30 participants [n = 10); sub-elite, cyclists with an U23 or amateur license (n = 12); recreational, cyclists that participate in cyclosportive events (n = 13). The inclusion criteria were to own a professional, U23, cyclosportive, or masters license. The exclusion criteria were (a) surgical procedures and injuries in the six months prior to the study and (b) use of performance-enhancing drugs in the six months prior to the study. After being informed of the benefits and potential risks of the investigation, all participants signed an informed consent form. The study followed the ethical guidelines of the 2013 Declaration of Helsinki and received approval from the Research Ethics Committee of the autonomous region of Aragon, Spain .G∗Power version 3.1.9.2  was usedicipants . Thirty-©, Spain) with a precision of 1 mm, and bodyweight (kg) was measured using scales of the same brand with a precision of 0.1 kg [Participants were weighed and measured by an internationally certified anthropometrist (ISAK level 2). Height (cm) was measured using the SECA-360 measuring rod  was used to assess the passive stiffness of the main muscles involved in the pedaling action, RF, VL, biceps femoris (BF), and GL, before and after the incremental exercise test. To ensure correct measurements, the assessment points were drawn on the skin following the indications of Hermens et al. [d = 3 mm). After the red light turned green, five short impulses  were produced automatically by the device in order to induce mechanical oscillations in the soft tissues. In order to guarantee the validity of the data obtained, only those evaluations in which the coefficient of variation was lower than 3% were considered. Otherwise, the assessment was repeated. All measurements were made by the same experienced researcher, and the intra- and inter-rater reliability for this device have been estimated in previous studies. [® device provides data on the recorded passive muscle stiffness  [A MyotonPROs et al.   . The mea2 was reached or, when not seen, at voluntary fatigue when at 100% of estimated HRmax, a respiratory exchange ratio of ≥1.15 and a rate of perceived exertion (RPE) of ≥18 [Participants performed an incremental exercise test with gas exchange analysis   in the l) of ≥18 . The 6–2) of ≥18 . All therstatix. Stiffness differences were assessed by fitting an independent linear mixed-effects model for each muscle  using the packages lme4 and lmerTest. The models included fixed-effects terms for time (pre and post), category , and their interaction. Time at pre and the recreational category were the reference category in each factor, respectively. Random slopes were allowed to vary between moments (time) and random intercepts were allowed to vary among participants (id). Main effects were obtained performing an analysis of variance with each model, and post-hoc pairwise comparisons were performed comparing estimated marginal means using the emmeans package. The effect size of main effects was reported using partial eta squared (η2P) and interpreted as follows: η2P < 0.01 “small”, η2P < 0.06 “medium”, η2P < 0.14 “large”. Differences in estimated marginal means and their 95% confidence intervals were reported as absolute effect size, and Cohen’s d with Hedges correction and their 95% confidence intervals were reported as standardized effect size. Cohen’s d was interpreted as follows: |d| < 0.2 “negligible”, |d| < 0.5 “small”, |d| < 0.8 “medium”, otherwise “large”. Normality of residuals was assessed using the Shapiro–Wilk test and Q–Q plots, heteroscedasticity was assessed using the Breusch–Pagan test, and model performance was evaluated using Akaike information criterion and R2. All assumptions and performance functions were assessed using the package performance. Statistical significance was assumed when p < 0.05.Statistical analyses were performed in R version 4.0.1 (R Core Team 2020) using RStudio (RStudio Team 2020). Variables were visually inspected and described as mean (standard deviation) using the package p = 0.001, Cohen’s d = 0.88) and elite groups , but not in the recreational group (p = 0.085) (p = 0.53), GL  = 0.9, p = 0.41), and BF  = 1, p = 0.39). Additionally, baseline stiffness was comparable between categories in all muscles. Stiffness increased over time in both knee extensors, RF  = 31.9, p < 0.001, η2P = 0.5) and VL  = 24.4, p < 0.001, η2P = 0.2), but no changes were observed in the knee flexors, GL  = 0.2, p = 0.63, η2P = 0) and BF  = 4.1, p = 0.052, η2P = 0.1).There was a significant correlation between time and category in the VL with stiffness increases in the sub-elite (= 0.085) . There wThe purpose of this study was to analyze the passive muscle stiffness of the main muscles involved in the pedaling action in a group of 35 cyclists classified by performance level. Furthermore, the effect of an incremental exercise test until exhaustion on the variations of passive muscle stiffness was also studied to determine whether performance level has an effect on the post-effort muscular response. The main findings of this study could be highlighted as; (i) there were no differences in the resting passive muscle stiffness of the muscles involved in the pedaling action between cyclists categorized by performance level, (ii) an exposition to an incremental exercise test until exhaustion caused an increase in passive muscle stiffness of the knee extensor muscles regardless of the performance group without resulting in modifications of the knee flexor and ankle extensor muscles, and (iii) only the VL differed in its behavior when differentiating elite and sub-elite categories from recreational cyclists. Therefore, it could be determined that there were no significant differences in the passive muscular stiffness analyzed in a resting situation regardless of the level of the cyclist. Furthermore, the subjection to an incremental test until exhaustion only caused an increase in the stiffness of the knee extensors (RF and VL) with significant differences between performance levels  only found for the VL. To the best of the authors’ knowledge, this has been the first study to compare cyclists’ muscle stiffness both in a resting and fatigued situation. In addition, the conclusions reported in this manuscript offer information for cyclists, coaches, and medical staff that help to understand the internal behavior of the muscles and could be considered as a training response variable.p = 0.018). In addition, they concluded by stating that muscular stiffness could be a characteristic that could contribute to a player’s ability to physically perform at an elite level. They also provided an explanation for the high injury rates at elite levels of performance by associating greater levels of stiffness with a higher injury rate [The muscular properties and their behavior during the pedaling action have been studied in the scientific literature ,35,36. Hury rate . Additioury rate .2max. This finding could be explained because previous studies have analyzed sport disciplines in which the speed component is key to performance [2max (348 ± 55 N/m–433 ± 115 N/m). It should be taken into consideration that, despite the lack of statistically significant differences, greater stiffness was observed in those groups with greater aerobic capacity (greater VO2max) in the analysis of the VL . This increase was not observed for the rest of the analyzed muscles: RF, BF, and GL.Regarding cycling, the studies performed by Wastford et al. and Uchiyama et al. should be highlighted. Both determined the importance of high stiffness levels for sprint specialties ,16. Uchiformance ,37. Thisp < 0.001). Contrarily to what was reported by previous authors, this increase could be explained because the time until the assessment was clearly different in these studies: 4h in the case of the Ironman and days in the case of the ultra-marathon. In our study, muscle stiffness was tested immediately after the incremental test, which may be considered as a relevant factor that may influence the results.The literature regarding post-effort stiffness in endurance sports is scarce. Both studies by García-Manso et al.  and Andop = 0.052). This could be due to the fact that most of the power during the pedaling action is produced by the RF and VL and to a lesser degree by the BF. This aspect is closely linked to the elevation of post-effort muscle stiffness [Our results match those obtained by Silva et al., who determined that the RF and VL were the muscles with the highest activation rates during the pedaling action. Regarding the antagonist muscle (BF), a lower but longer total activation was observed . Two yeatiffness ,41. Addip = 0.63), an aspect that contradicts the results of some studies that highlight the importance of this muscle group involved in flexion and extension of the ankle. Pruyn et al. studied the relationship between muscle stiffness using myometry and variables related to performance in different modalities of team sports and highlighted the importance of enhancing the muscle group composed by the gastrocnemius, soleus, and Achilles tendon in order to achieve success in these sports modalities [In relation to the GL, only three studies have studied the muscular stiffness of this muscle through myometry ,35,42. T2max) presented a behavior that did not match what was seen in the higher-level group. This discrepancy between riders characterized by different fitness levels may suggest that the stiffness control of the knee extensor muscles could be useful as a possible reference for functional tests in the periodic evaluation of cyclists.Finally, the correlation between the moment of measurement (pre and post effort) and the study category should be highlighted. In this case, cyclists in the elite and sub-elite groups presented significant differences in the stiffness values of the VL muscle compared to the recreational group. This finding is related to what was reported by Ditroilo et al., who found that cyclists with higher baseline stiffness levels presented greater reductions in muscle stiffness after fatiguing . This wo2max = 49.9 ± 3.1 mL/kg/min), and this could be a limitation that had an impact on the results. In the same way, an incremental test generates maximum aerobic metabolic stimulation but does not induce the same levels of structural fatigue. Future lines of research should not only use groups characterized by lower performance levels but also control groups that would allow a global vision of the muscular stiffness. In addition, the behavior of the muscle should be analyzed in more fatiguing situations such as stage races while, at the same time, considering the specialty of the cyclist. Given that the stiffness values of the VL muscle differed between recreational, elite, and sub-elite cyclists, future research should assess whether this marker could be used to differentiate cyclists of varying fitness levels and its potential applicability for the monitoring of training load.Despite the fact that the study sample used in this work covered very high levels of performance, the recreational group presented high basal aerobic levels (VOThe results of this study suggest that there are no differences in the passive muscle stiffness of the muscles involved in the pedaling action between cyclists categorized by performance level. Exposition to an incremental exercise test until exhaustion caused an increase in passive muscle stiffness of the knee extensor muscles, regardless of the performance group, without resulting in modifications of the knee flexor and ankle extensor muscles. Only the VL differed in its behavior when differentiating elite and sub-elite categories from recreational cyclists.


Multivariate logistic regression analysis showed that the adiponectin level  was an independent predictor of aortic stiffness in elderly diabetic persons. Multivariate forward stepwise linear regression analysis also demonstrated that the adiponectin level  was negatively associated with cfPWV values in older diabetic patients. In conclusion, serum adiponectin is negatively correlated with cfPWV and is an independent predictor of aortic stiffness in elderly diabetic persons.Adiponectin has anti-inflammatory activity against atherosclerosis. Aortic stiffness is a common manifestation of atherosclerosis in diabetes mellitus and elderly persons. This study aimed to evaluate whether low serum adiponectin levels were associated with aortic stiffness in geriatric diabetic patients. Blood samples were obtained from 130 diabetic participants aged ≥ 65 years. We defined high aortic stiffness based on a carotid–femoral pulse wave velocity (cfPWV) of >10 m/s. Circulating adiponectin concentrations were examined using enzyme-linked immunosorbent assays. Sixty-six participants (50.8%) had aortic stiffness. Patients with aortic stiffness had lower serum adiponectin concentrations than those in the control group ( Diabetes mellitus (DM), a chronic metabolic disorder encompassing insulin resistance and hyperglycemia, remains a global healthcare burden . There wArterial stiffness, a pathological condition with low-grade inflammation and abnormal regulation of collagen, elastin fibers, and cellular elements, represents subclinical organ damage and future cardiovascular disease (CVD) development ,5. AortiPrevious studies revealed that hypoadiponectinemia had negative effects on arterial stiffness in young, normotensive patients with type 1 or type 2 DM ,11. HoweThe Research Ethics Committee of Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, approved this study IRB103-136-B). A total of 130 elderly patients with type 2 DM (≥65 years of age) were enrolled in this cross-sectional study conducted from November 2014 to March 2015 in a medical center in Hualien, Taiwan. All patients included in this study provided informed consent prior to enrollment. DM was defined as a fasting plasma glucose level exceeding 126 mg/dL or a patient using oral hypoglycemic medications or insulin [6-B. A toWhile wearing light clothing without shoes, participants were weighed to the nearest 0.5 kg, and their height was measured to the nearest 0.5 cm. Body mass index (BMI) was calculated by dividing the weight (kg) by the height (m) squared. The waist circumference at the shortest point between the lower edge of the rib cage and the iliac crest was measured ,15.g for 10 min. Serum levels of blood urea nitrogen (BUN), creatinine, fasting glucose, glycated hemoglobin (HbA1c), total cholesterol, triglycerides (TG), and low-density lipoprotein cholesterol (LDL-C), as well as urine protein-to-creatinine ratio (UPCR) using random spot urine testing, were measured using an autoanalyzer  [Overnight fasting blood samples containing approximately 5 mL were immediately centrifuged at 3000× Germany) ,15. The Germany) ,15. The R-timing reference. We performed continuous pulse wave recording at two superficial artery sites . By subtracting the distance from the carotid measurement point to the sternal notch from the distance from the sternal notch to the femoral measurement site, the carotid–femoral distance was obtained. We use integration software to process each set of pulse wave and ECG data to calculate the mean time difference between the R-wave and pulse wave on a beat-to-beat basis, with an average of 10 consecutive cardiac cycles. The distance and mean time difference between the two recorded points were used to calculate the cfPWV. The quality indicators included in the software are designed to ensure data consistency. We defined aortic stiffness as the cfPWV values > 10 m/s, and those whose values were ≤10 m/s were included in the control group in our study, according to the guidelines published by the European Society of Cardiology and the European Society of Hypertension [Aortic stiffness was evaluated by measuring the cfPWV values using pressure applanation tonometry , as previously described ,15,16,17rtension .t-test (two-tailed) and are presented as the mean ± standard deviation. Non-normally distributed data are represented by the median and interquartile range, and comparisons between participants were examined via the Mann–Whitney U test . The chi-square test was used to analyze data expressed as the number of patients. Multivariate logistic regression analysis was performed to test the independence of variables that were significantly related to aortic stiffness in elderly diabetic patients. Because age, TG, fasting glucose, BUN, creatinine, and UPCR were not normally distributed, these parameters underwent logarithmic transformations with base 10 to achieve normality. Variables that were significantly associated with cfPWV values among elderly diabetic populations were tested for independence in a linear regression analysis and then a multivariate forward stepwise regression analysis. The area under the receiver operating characteristic curve was calculated to identify the optimal adiponectin levels and significant variables associated with aortic stiffness. We used IBM SPSS Statistics Version 19.0  for data analyses. A p-value < 0.05 was considered statistically significant.Data were tested for normal distribution using the Kolmogorov–Smirnov test. Data distributed normally were compared using Student’s independent p < 0.001). The medications use included angiotensin-converting enzyme inhibitors , angiotensin receptor blockers , β-blockers , calcium channel blockers , statins , fibrate , metformin , sulfonylureas , dipeptidyl peptidase 4 inhibitors , peroxisome proliferator-activated receptor gamma agonists , and insulin . No statistically significant differences were observed in sex, hypertension, or the use of ACEi, ARB, β-blockers, CCB, statins, fibrate, metformin, sulfonylureas, DDP-4 inhibitors, PPAR-γ agonists, or insulin between the two groups.Demographic, clinical, and biochemical parameters and drugs used by the 130 elderly diabetic patients are presented in p = 0.001). Multivariate logistic regression analysis adjusted for sex and BMI showed a 5.6% decrease in the risk of aortic stiffness  for every 1 μg/mL adiponectin elevation (Model 1). After multivariate logistic regression analysis with Model 1 adjusted for fasting glucose, glycated hemoglobin, total cholesterol, and LDL-C, every 1 μg/mL adiponectin elevation showed a 5.7% drop in the risk of aortic stiffness  in Model 2. Multivariate logistic regression analysis using Model 2 adjusted for all drugs used in this study also represented a decreased risk of aortic stiffness of 7.0%  for every 1 μg/mL adiponectin elevation (Model 3). Multivariate logistic regression analysis using Model 3 adjusted for age, waist circumference, SBP, DBP, TG, creatinine, eGFR, UPCR, and adiponectin in this study also represented a decreased risk of aortic stiffness of 6.1%  for every 1 μg/mL adiponectin elevation (Model 4). Each of these analyses acknowledged that the serum adiponectin level had an inverse association with aortic stiffness in elderly diabetic participants. By using the ROC curve, the best cut-off serum value of adiponectin that could be used to predict aortic stiffness in elderly diabetic participants was 23.7 µg/mL, with the area under the receiver operating characteristic curve of 0.662 , sensitivity of 48.5%, and specificity of 82.8%. The diagnostic performance of adiponectin, waist circumference, SBP, DBP, TG, and eGFR as shown in The unadjusted and multivariate logistic regression analyses of the parameters significantly associated with aortic stiffness, including age, waist circumference, SBP, DBP, TG, creatinine, eGFR, UPCR, and adiponectin levels are presented in r = 0.173, p = 0.049), SBP , DBP , logarithmically transformed TG , log-creatinine , and log-UPCR  were positively correlated with cfPWV values, while eGFR , and adiponectin  had negative correlations. Multivariate forward stepwise linear regression analysis of the variables significantly associated with cfPWV values revealed that SBP , log-TG , and adiponectin  were independent parameters of cfPWV values in elderly diabetic participants.Analysis of cfPWV values with variables in elderly diabetic participants via univariate and multivariate linear analyses is shown in Our cross-sectional study showed that serum adiponectin concentration was inversely associated with cfPWV values in elderly diabetic participants, while SBP and log-TG were positively correlated. Hypoadiponectinemia was associated with aortic stiffness in elderly diabetic participants after adjusting for covariates.Arterial stiffness, a degenerative process predominantly affecting the extracellular matrix of elastic arteries under the influence of aging and other risks, is a marker of CVD events independent of the traditional atherosclerosis risk factors . NoninvaA previous study revealed that increased aortic stiffness was a major predictor of CVD occurrence and mortality in patients with type 2 DM . DM patiAdiponectin, which binds to distinct G protein-coupled receptors AdipoR1 and AdipoR2, acts as an insulin sensitizer and displays antidiabetic effects . HypoadiThere are some limitations to our research. Firstly, this was a cross-sectional study with a limited sample size, and all patients were recruited from the same hospital; therefore, our cohort may not truly represent the wider population, and further longitudinal research is necessary before causality can be established. Secondly, there are multiple isoforms of serum adiponectin, and high-molecular-weight adiponectin has the most powerful biologic effects . AlthougHypoadiponectinemia is positively associated with cfPWV values and is recognized as a consistent and significant parameter associated with aortic stiffness in elderly diabetic persons.


Introduction: One of the principal complications after total knee arthroplasty (TKA) is stiffness. There are no publications concerning stiffness after unicompartmental knee arthroplasty (UKA). Study objectives were to describe the incidence of stiffness after UKA, to look for risk factors, and to describe safe and effective arthroscopic treatment. Methods: There were 240 UKA performed between March 2016 and January 2019 included. Robotic-assisted surgery was performed in 164 patients and mechanical instrumentation in 76 patients. Stiffness was defined as flexion < 90° or a flexion contracture > 10° during the first 45 post-operative days. Patients with stiffness were treated with arthroscopic arthrolysis. Several factors were studied to look for risk factors of stiffness: body mass index, gender, age, mechanical or robotic instrumentation, preoperative flexion, previous meniscectomy, and anticoagulant treatment. Arthrolysis effectiveness was evaluated by flexion improvement and UKA revision rate. Results: 22 patients (9%) developed stiffness. Mechanical instrumentation significantly increased the risk of stiffness with OR = 0.26 and p = 0.005. Robotic-assisted surgery decreased the risk of stiffness by five-fold. Before arthrolysis, mean knee flexion was 79°, versus 121° (53% improvement) after arthroscopic arthrolysis. Only 2 patients (9%) underwent UKA revision after arthrolysis. Discussion: Stiffness after UKA is an important complication with an incidence of 9% in this study. Arthroscopic arthrolysis is a safe and effective treatment with a range of motion improvement of > 50%. Robotic-assisted surgery significantly decreases the risk of postoperative stiffness.Level of evidence: Level III, therapeutic study, retrospective cohort study Unicompartmental knee arthroplasty (UKA) is a common treatment for partial knee osteoarthritis. Outcomes of UKA have improved in recent years, likely due to improved surgical technique and superior implant designs. Performing UKA with robotic assistance results in better implant positioning and decreased complications , 2. NumeStiffness is a common complication of TKA, with a reported incidence of between 1% and 13% postoperatively , 12; treStiffness is not frequently reported in UKA. Only a few studies report this complication , 14, andHypothesis was that robotic instrumentation decrease the rate of stiffness versus mechanical instrumentation and that arthroscopic debridement is a safe and efficient treatment of stiffness after UKA.This single-centre retrospective study was based on prospectively collected data of a cohort of 240 consecutive primary UKAs performed at our department between March 2016 and January 2019 by two senior surgeons. Inclusion criteria were all patients who underwent a UKA in that study period with a minimum follow-up of 1 year.Exclusion criteria were patients with previous knee fracture, previous osteotomy, anterior cruciate ligament reconstruction, or sagittal instability before surgery to decrease the risk of UKA failure . CharactAll procedures were performed by the ethical standards of the institutional and/or national research committee, the 1964 Helsinki declaration, and its later amendments, or comparable ethical standards.®)  .®)  .®) was used in robotic-assisted surgery [The BlueBelt Navio robotic surgical system .The treatment of stiffness consisted of arthroscopic arthrolysis. Two standard anterior portals were made: inferolateral and inferomedial, and only if necessary, a third superolateral portal was made. A step-by-step approach was used as described by Volchenko et al.  for TKA ®) was performed for 20 h per each 24 h during immediate 7 days after surgery. No prophylactic thromboembolism anticoagulants were administered to reduce the risk of hematoma and adhesions reforming. Patients underwent clinical and radiological evaluation at 21 days, 45 days, 3 months, and 1 year postoperatively and then every year thereafter.Patients underwent physiotherapy with no restrictions of flexion. Continuous passive motion with Kinetec Spectra Essential™ .A Firstly, stiffness incidence has been evaluated: 22 patients (9%) developed stiffness .At a second time, risk factors to present stiffness have been evaluated.Different risk factors studied were body mass index (BMI), age, mechanical versus robotic instrumentation, meniscectomy antecedent, preoperative flexion, taking anticoagulant, or not and taking antiplatelet agents or not and kind of implant. Results are summarized in p = 0.005) with odds ratio, OR = 0.2. Thus, using robotic instrumentation reduces the risk of stiffness by > 5 times after UKA. Another interesting risk factor with an important OR was found: meniscectomy antecedent (OR = 2.4). The difference was no significant, but patients with meniscectomy antecedent have twice the risk to present stiffness.Only one risk factor studied seemed to have a significant impact on stiffness: mechanical instrumentation . Only 2 patients (9%) had a failure of arthrolysis and they were revised to a TKA.p = 0.005). Patients with meniscectomy antecedent present twice the risk to have stiffness after UKA.The most important finding of this study was that stiffness is an important complication after UKA, with 9% of the patients in this cohort presenting with stiffness after UKA. Arthroscopic debridement is an effective treatment with only 9% of patients still requiring revision to TKA after arthrolysis. Performing robotic-assisted UKA surgery significantly reduced the risk of stiffness by > 5 times (After TKA, stiffness is a common complication. Multiple treatments are recommended: manipulation under anesthesia, arthroscopic arthrolysis, open surgery. Volchenko et al.  describeRegarding UKA, manipulation under anesthesia can be effective but may result in complications such as fracture, rupture of the extensor mechanism, or chondral damage . ManipulHurst et al.  describeIn our study, the robot seems to reduce the risk of stiffness. Several causes can explain this result.Firstly, robotic-assisted surgery seems to improve implant positioning. Batailler et al.  had alreIndeed, Herry et al.  have shoThe use of the robot allows better restitution of the physiological kinematics of the knee and this may explain the best post-operative follow-up and therefore the reduction of the risk of stiffness.Then, several studies have shown a decrease in postoperative pain with the use of the robot , 21. ThiPostoperative management is a very important point for us after stiffness treatment.After primary TKA, continuous passive motion does not provide an additional benefit compared to traditional physiotherapy . HoweverIt is important to note that there is very little literature reporting upon stiffness after UKA. There are numerous studies concerning stiffness after TKA, but not for UKA. This is surprising given that the rate of stiffness is around 9%, which is not much lower than a 12% stiffness rate after TKA. Stiffness after UKA is an important complication that deserves closer evaluation.There are some limitations to this study that need to be acknowledged. By nature of the retrospective study design, some degree of bias could have been introduced, since patients were not randomized and indication bias for the use of robotic assistance surgery versus mechanical instrumentation may have occurred. Then, the short follow-up after arthroscopic treatment may overestimate the effectiveness of arthroscopic arthrolysis, however, the literature tells us that most stiffness occurs within the first two months.Stiffness after UKA is an important complication with an incidence of 9% in this study. Arthroscopic arthrolysis is a safe and effective treatment with a range of motion improvement of > 50%. Robotic-assisted surgery significantly decreases the risk of postoperative stiffness.Prof. Sébastien Lustig is a consultant for Medacta, Heraeus, Corin, Amplitude, Groupe Lépine, Depuy, Smith & Nephew, Stryker. Prof. Sébastien Lustig receives support from Corin and Amplitude. Prof. Sébastien Lustig is a board member of KSSTA, Maitrise Orthopédique. The other authors declare that they have no conflicts of interest.Prof. Elvire Servien is a consultant for Corin and Smith & Nephew.