Effects of Impairment-Based Exercise on Performance of Specific Self-Reported Functional Tasks in Individuals With Knee Osteoarthritis OARSI recommended performance-based tests to assess physical function in people diagnosed with hip or knee osteoarthritis. The effectiveness of a self-management program on quality of life for knee osteoarthritis (OA) patients. Physical function and properties of quadriceps femoris muscle in men with knee osteoarthritis. Evaluation of clinically relevant states in patient reported outcomes in knee and hip osteoarthritis: the patient acceptable symptom state. Effect of an education programme for patients with osteoarthritis in primary care - a randomized controlled trial The effects of an exercise program for older adults with osteoarthritis of the hip. Determinants of self-report outcome measures in people with knee osteoarthritis. Moving to maintain function in knee osteoarthritis: evidence from the osteoarthritis initiative. Cultural adaptation and validation of a German version of the Arthritis Impact Measurement Scales (AIMS2). Performance of the Assessment of Quality of Life Measure in People With Hip and Knee Joint Disease and Implications for Research and Clinical Use Effectiveness of behavioral graded activity in patients with osteoarthritis of the hip and/or knee: A randomized clinical trial. Evaluation of clinically relevant changes in patient reported outcomes in knee and hip osteoarthritis: the minimal clinically important improvement. The effects of a health educational and exercise program for older adults with osteoarthritis for the hip or knee. Patient and provider interventions for managing osteoarthritis in primary care: protocols for two randomized controlled trials Physical therapy is effective for patients with osteoarthritis of the knee: a randomized controlled clinical trial. Manual therapy in osteoarthritis of the hip: outcome in subgroups of patients.
Background Little is known regarding how impairment-based exercises may improve performance of specific functional tasks in people with knee osteoarthritis ( OA ) . Objective The purpose of this study was to compare the probability that participation in an impairment-based exercise program or the same impairment-based program supplemented with agility and perturbation training will improve patient-reported function on specific functional tasks . Design This study was a secondary analysis of data from a r and omized clinical trial . Setting The study was conducted in the outpatient physical therapy clinic of a large , university-based health center . Participants One hundred eighty-three people with knee OA ( 122 women , 61 men ) participated . Interventions Participants were r and omly assigned to either a group that received agility and perturbation training with st and ard exercise therapy or a group that received only the st and ard exercise . Measurements Specific functional items were taken from the physical function subscale of the Western Ontario and McMasters Universities Osteoarthritis Index , the Lower Extremity Function Scale , and the Activities of Daily Living Scale of the Knee Outcome Survey . Results The probability of self-reported improvement in a variety of specific functional tasks was low following participation in either of the exercise programs . When only participants with moderate to severe difficulty performing specific functional tasks were considered in the analysis , the probability of success improved but was still limited . Limitations The results are generalizable only to self-reported assessment of performance of specific functional tasks . Conclusions Impairment-based exercise may not be enough to make substantial improvement in performance of specific functional tasks .  Task-specific exercise approaches need to be explored for people with knee OA OBJECTIVES To recommend a consensus-derived set of performance-based tests of physical function for use in people diagnosed with hip or knee osteoarthritis ( OA ) or following joint replacement . METHODS An international , multidisciplinary expert advisory group was established to guide the study . Potential tests for consideration in the recommended set were identified via a survey of selected experts and through a systematic review of the measurement properties for performance-based tests . A multi-phase , consensus-based approach was used to prioritize and select performance-based tests by applying decision analysis methodology ( 1000Minds software ) via online decision surveys . The recommended tests were chosen based on available measurement-property evidence , feasibility of the tests , scoring methods and expert consensus . RESULTS Consensus incorporated the opinions of 138 experienced clinicians and research ers from 16 countries . The five tests recommended by the advisory group and endorsed by Osteoarthritis Research Society International ( OARSI ) were the  30-s chair-st and test , 40 m fast-paced walk test , a stair-climb test , timed up- and -go test and 6-min walk test . The first three were recommended as the minimal core set of performance-based tests for hip or knee OA . CONCLUSION The OARSI recommended set of performance-based tests of physical function represents the tests of typical activities relevant to individuals diagnosed with hip or knee OA and following joint replacements . These tests are complementary to patient-reported measures and are recommended as prospect i ve outcome measures in future OA research and to assist decision-making in clinical practice . Further research should be directed to exp and ing the measurement-property evidence of the recommended tests PURPOSE To evaluate the effectiveness of the Taipei Osteoarthritis Program ( TOAP ) for community elderly persons who suffer from knee OA . METHODS A quasi-experimental study was conducted between January 2008 and December 2008 . Two hundred and five community-dwelling individuals aged 67±10 years with knee OA were recruited from four districts in Taipei City and r and omized . By a clustered r and omization according to the districts , 114 participants were in the intervention group ( IG ) with a 4-week TOAP program and 91 participants were in the control group ( CG ) with routine care . The main outcome measures included health-related quality of life ( HRQOL ) and disability level , which were assessed by the Short Form-36 Taiwan Version ( T-SF36 ) and the Western Ontario McMaster Universities Arthritis Index Taiwan Version ( T-WOMAC ) , respectively , and were repeatedly measured at the baseline , post invention ( 4 weeks after baseline ) , and follow-up ( 8 weeks after baseline ) . RESULTS Subjects in the IG increased their changes of GH scores from baseline to post-intervention and follow-up , which were significantly more than those of subjects in the CG ( p=0.011 and 0.005 , respectively ) . Significant difference of changes was also found at follow-up for the mental component scale between the groups ( p=0.013 ) . There was no change in disability level . CONCLUSIONS The arthritis self-management program improved the psychological outcomes among the participants , but it had no significant effect on a self-reported disability level OBJECTIVES To examine the objective physical function of the lower extremities , to measure the properties of quadriceps femoris muscle ( QFM ) , and to assess subjective disabilities in men with knee osteoarthritis ( OA ) and to compare the results with those obtained from age- and sex-matched control subjects . DESIGN Cross-sectional study . SETTING Rehabilitation clinic in a university hospital . PARTICIPANTS Male volunteers ( n=54 ) ( age range , 50 - 69y ) with knee OA and r and omly selected healthy , age- and sex-matched control subjects ( n=53 ) . INTERVENTIONS Not applicable . MAIN OUTCOME MEASURES Physical function evaluated with a test battery including the QFM composition measurement , the Western Ontario and McMaster Universities Osteoarthritis Index ( WOMAC ) , and the R AND 36-Item Short-Form Health Survey , version 1.0 .  RESULTS Knee OA patients had 13 % to 26 % poorer ( P range , .050-.001 ) physical function and muscle strength compared with the controls . There were also significant differences in QFM composition . WOMAC ( P range , .050-.001 ) and muscle strength ( P<.001 ) associated with physical function tests , but subjective pain correlated with neither physical function nor muscle strength in knee OA patients . The radiographic knee OA grade did not have any significant effect on physical function , but passive knee motion , knee extension strength , and WOMAC were related to the severity of the disease ( P<.05 ) . CONCLUSIONS The patients with knee OA exhibited impaired physical function and muscle strength and QFM composition compared with healthy controls . The severity of radiographic knee OA clearly had adverse effects on functional ability at the later stages of the disease . The results highlight the effect of QFM strength on physical function as well as the importance of patient 's subjective and objective physical function when deciding on knee OA treatment policy BACKGROUND The patient acceptable symptom state ( PASS ) is the value beyond which patients can consider themselves well . This concept can help in interpreting results of clinical trials . OBJECTIVE To determine the PASS estimate for patients with knee and hip osteoarthritis ( OA ) by assessing pain , patient 's global assessment of disease activity , and functional impairment . METHODS A 4 week prospect i ve multicentre cohort study of 1362 out patients with knee or hip OA was carried out . Data on assessment of pain and patient 's global assessment of disease , measured on visual analogue scales , and functional impairment , measured on the Western Ontario McMaster Universities Osteoarthritis Index ( WOMAC ) function subscale , were collected at baseline and final visits . The patients assessed their satisfaction with their current state at the final visit . An anchoring method based on the patient 's opinion was used . RESULTS For patients with knee and hip OA , the estimates of PASS were , respectively , 32.3 and 35.0 mm for pain , 32.0 and 34.6 mm for patient global assessment of disease activity , and 31.0 and 34.4 points for WOMAC function score . The PASS varied moderately across the tertiles of baseline scores but not across age , disease duration , or sex . CONCLUSION The use of PASS in clinical trials would provide more meaningful results expressed as a proportion of patients in an acceptable symptom state Background Osteoarthritis ( OA ) is a degenerative disease , considered to be one of the major public health problems . Research suggests that patient education is feasible and valuable for achieving improvements in quality of life , in function , well-being and improved coping . Since 1994 , Primary Health Care in Malmö has used a patient education programme directed towards OA . The aim of this study was to evaluate the effects of this education programme for patients with OA in primary health care in terms of self-efficacy , function and self-perceived health . Method The study was a single-blind , r and omized controlled trial ( RCT ) in which the  EuroQol-5D and Arthritis self-efficacy scale were used to measure self-perceived health and self-efficacy and function was measured with Grip Ability Test for the upper extremity and five different functional tests for the lower extremity . Results We found differences between the intervention group and the control group , comparing the results at baseline and after 6 months in EuroQol-5D ( p < 0.001 ) and in st and ing one leg eyes closed ( p = 0.02 ) in favour of the intervention group . No other differences between the groups were found . Conclusion This study has shown that patient education for patients with osteoarthritis is feasible in a primary health care setting and can improve self-perceived health as well as function in some degree , but not self-efficacy . Further research to investigate the effect of exercise performance on function , as well as self-efficacy is warranted . Trial registration The trial is registered with Clinical Trials.gov . Registration number : OBJECTIVE . Evaluation of an 8-week exercise program with strength training and lifestyle advice for older adults with osteoarthritis ( OA ) of the hip . Outcome measures were pain , hip function , disability , quality of life ( QOL ) , and body mass index ( BMI ) . METHODS Inclusion criteria for this r and omized controlled trial were : age > or=55 years , clinical diagnosis of OA according to American College of Rheumatology criteria , and living independently . Interview and physical data were collected at baseline , post-test , and followup ( 3 mo ) by trained interviewers and physical therapists with vali date d instruments : Harris Hip Score , Sickness Impact Profile , Groningen Activity Restriction Scale , functional tests ( walking , timed Up & Go , ascending and descending stairs , and toe reaching ) , and visual analog scales ( pain and QOL ) . Data were analyzed on an intention-to-treat basis . Effect sizes were calculated . RESULTS There were 109 participants ( 55 experimental , 54 controls ) . The 15 participants who dropped out were characterized by less tolerance to pain and younger age . The program had a positive effect on pain ( moderate effect at post-test and small effect at followup ) , hip function ( small effect at post-test ) , self-reported disability ( small effect at followup ) , and the timed Up & Go test ( small effect at followup ) . It did not affect QOL , other measures of observed disability , or BMI . CONCLUSION The exercise program had positive effects on pain and hip function , which are important mediators of disability . This study fulfilled a need for older adults with hip OA and provides evidence of the benefit of exercise in the management of hip OA OBJECTIVES To identify the determinants of self-report mobility measures in people with knee osteoarthritis ( OA ) and to compare self-report measures with physical performance . DESIGN Cross-sectional , prospect i ve . SETTING Motor performance laboratory and human mobility research center . PARTICIPANTS A convenient sample of 54 participants with medial compartment knee OA ( 32 women , 22 men ; age 68.3+/-8.7y ; range , 50 - 87y ) . Three participants were excluded because of the presence of lateral knee OA on radiographs . INTERVENTIONS Not applicable . MAIN OUTCOME MEASURES Self-reports were recorded by using the Western Ontario McMaster Universities Osteoarthritis Index ( WOMAC ) and the Medical Outcomes Study 36-Item Short-Form Health Survey ( SF-36 ) . Performance measures included the  six-minute walk test ( 6MWT ) , Timed Up & Go ( TUG ) test , and a st and ardized stair-climbing task ( STR ) . RESULTS Stepwise linear regression analysis identified models that included pain , quadriceps and hamstrings strength , and depression to explain 62 % to 73 % of the variance in scores on the physical functioning subscale of the WOMAC and the SF-36 . These self-report measures had a moderate relation ( r range , .46-.64 ) with performance measures ( 6MWT , TUG , STR ) . CONCLUSIONS Self-report measures were strongly related to pain ; physical performance measures were strongly related to self-efficacy . Regression models showed that self-report scores reflect pain , knee strength , and depression . The relation between self-report and performance measures was moderate , suggesting that these examine different aspects of mobility OBJECTIVES To investigate the association between baseline physical activity and 1-year functional performance in adults with knee osteoarthritis ( OA ) . DESIGN Prospect i ve cohort study of knee OA development and progression with 1-year follow-up . SETTING Community . PARTICIPANTS Osteoarthritis Initiative public data on adults with knee OA ( n=2274 ; age , 45 - 79y ) who participated in functional performance assessment s ( timed 20-m walk and chair st and test ) at baseline and 1-year follow-up . INTERVENTIONS Not applicable . MAIN OUTCOME MEASURE A good 1-year performance outcome ( separately defined for walk time and chair st and measures ) was improvement from baseline quintile or maintenance in the best quintile . RESULTS Almost 2 in 5 persons with radiographic knee OA improved or maintained high performance at 1 year .  Physical activity  measured by the  Physical Activity Scale for the Elderly  ( PASE ) was significantly associated with good walk rate and chair st and outcomes ( odds ratio per 40 units PASE [ 95 % confidence interval]=1.13 [ 1.13 , 1.17 ] and 1.10 [ 1.05 , 1.15 ] , respectively ) , as were participation in sports/recreational activities ( 1.45 [ 1.23 , 1.71 ] and 1.29 [ 1.09 , 1.51 ] , respectively ) and lifestyle activities ( 1.11 [ 1.06 , 1.16 ] and 1.09 [ 1.04 , 1.14 ] , respectively ) . An independent protective relationship for these physical activity measures approached significance after adjusting for sociodemographic and health factors . Older adults reported the least baseline physical activity and least frequent good 1-year outcomes . CONCLUSIONS These findings support public health recommendations to be physically active in order to preserve function for persons with knee OA .  Physical activity messages should specifically target older adults whose low activity levels may jeopardize their ability to maintain functional performance OBJECTIVE To vali date a translated and culturally adapted version of the Arthritis Impact Measurement Scale ( AIMS ) 2 in primary care patients with osteoarthritis ( OA ) of the hip and knee . METHOD The AIMS 2 was translated into German and culturally adapted . The question naire then was administered to 220 primary care patients with OA of the knee or hip . Two hundred and nine question naires were returned and analysed . Test-retest reliability was tested in 50 r and omly selected patients , of those 42 completed the question naire after 2 weeks for a second time . RESULTS Item-scale correlations were reasonably good as well as the discriminative power of separate scales . The assessment of internal consistency reliability also revealed satisfactory values ; Cronbach 's alpha was 0.77 or higher for all scales . The test-retest reliability , estimated in an intraclass correlation coefficient ( ICC ) , exceeded 0.90 , except the " social activities " scale ( 0.87 ) . Since only patients with OA of the lower limb were enrolled , substantial floor effects occurred in the " arm function " ( 28.2 % ) and the " h and and finger function " scale ( 29.2 % ) . The principal factor analysis confirmed the postulated three-factor structure with a physical , physiological and social dimension , explaining 48.5 % , 13.9 % and 6.8 % of the variation , respectively . External validity was assessed by calculating correlations to the Western Ontario and MacMaster ( WOMAC ) osteoarthritis question naire a pain visual analogue scale ( VAS ) and the Kellgren score as well as to disease duration . Spearman 's " R " achieved satisfactory values for the corresponding WOMAC scales and the pain-VAS . Correlations with disease duration as well as with the radiological grading were low . CONCLUSION The GERMAN- AIMS 2 is a reliable and valid instrument to assess the quality of life ( QoL ) in primary care patients suffering from OA To comprehensively evaluate the performance of the Assessment of Quality of Life ( AQoL ) instrument for measuring health‐related quality of life ( HRQOL ) in people with hip and knee joint disease ( arthritis or osteoarthritis ) OBJECTIVE To determine the effectiveness of a behavioral grade d activity program ( BGA ) compared with usual care ( UC ; exercise therapy and advice ) according to the Dutch guidelines for physiotherapy in patients with osteoarthritis ( OA ) of the hip and /or knee . The BGA intervention is intended to increase activity in the long term and consists of an exercise program with booster sessions , using operant treatment principles . METHODS We conducted a cluster r and omized trial involving 200 patients with hip and /or knee OA . Primary outcome measures were pain ( visual analog scale [ VAS ] and Western Ontario and McMaster Universities Osteoarthritis Index [ WOMAC ] ) , physical function ( WOMAC ) , and patient global assessment , assessed at weeks 0 , 13 , 39 , and 65 . Secondary outcome measures comprised tiredness ( VAS ) , patient-oriented physical function ( McMaster Toronto Arthritis Patient Preference Disability Question naire [ MACTAR ] ) , 5-meter walking time , muscle strength , and range of motion . Data were analyzed according to intent-to-treat principle . RESULTS Both treatments showed short-term and long-term beneficial within-group effects . The mean differences between the 2 groups for pain and functional status were not statistically significant . Significant differences in favor of BGA were found for the MACTAR functional scale and 5-meter walking test at week 65 . CONCLUSION Because both interventions result ed in beneficial long-term effects , the superiority of BGA over UC has not been demonstrated . Therefore , BGA seems to be an acceptable method to treat patients with hip and /or knee OA , with equivalent results compared with UC BACKGROUND In clinical trials , at the group level , results are usually reported as mean and st and ard deviation of the change in score , which is not meaningful for most readers . OBJECTIVE To determine the minimal clinical ly important improvement ( MCII ) of pain , patient 's global assessment of disease activity , and functional impairment in patients with knee and hip osteoarthritis ( OA ) . METHODS A prospect i ve multicentre 4 week cohort study involving 1362 out patients with knee or hip OA was carried out . Data on assessment of pain and patient 's global assessment , measured on visual analogue scales , and functional impairment , measured on the Western Ontario McMaster Universities Osteoarthritis Index ( WOMAC ) function subscale , were collected at baseline and final visits . Patients assessed their response to treatment on a five point Likert scale at the final visit . An anchoring method based on the patient 's opinion was used . The MCII was estimated in a subgroup of 814 patients ( 603 with knee OA , 211 with hip OA ) . RESULTS For knee and hip OA , MCII for absolute ( and relative ) changes were , respectively , ( a ) -19.9 mm ( -40.8 % ) and -15.3 mm ( -32.0 % ) for pain ; ( b ) -18.3 mm ( -39.0 % ) and -15.2 mm ( -32.6 % ) for patient 's global assessment ; ( c ) -9.1 ( -26.0 % ) and -7.9 ( -21.1 % ) for WOMAC function subscale score . The MCII is affected by the initial degree of severity of the symptoms but not by age , disease duration , or sex . CONCLUSION Using criteria such as MCII in clinical trials would provide meaningful information which would help in interpreting the results by expressing them as a proportion of improved patients OBJECTIVE Evaluation of a self-management program for patients with osteoarthritis ( OA ) of the hip or knee . The program , which consisted of 6 weekly sessions of 2 hours , included health education by a peer and physical exercises taught by a physical therapist . METHODS R and omized controlled trial . Inclusion criteria were diagnosis of OA of the hip or knee according to ACR clinical and radiographic criteria and age 55 to 75 years . EXCLUSION CRITERIA on waiting list for joint replacement . There were pretest , posttest , and followup ( 6 months ) assessment s. The experimental group consisted of 56 patients , the control group 49 . Outcome variables were pain , quality of life , activity restrictions , knowledge about OA , self-efficacy , body mass index ( BMI ) , and mobility measures . Attention was also paid to effects on health care utilization and lifestyle behavior . RESULTS Significant MANOVA group x time effects ( p < 0.05 , one-sided ) were found for pain , quality of life , strength of the left M. quadriceps , knowledge , self-efficacy , BMI , physically active lifestyle , and visits to the physical therapist . Most effects were moderate at posttest assessment and smaller at followup . No effects were found for range of motion and functional tasks . CONCLUSION The program was reasonably effective , but more attention should be paid to proactive followup interventions and to the selection of participants Background Osteoarthritis ( OA ) of the hip and knee are among the most common chronic conditions , result ing in substantial pain and functional limitations . Adequate management of OA requires a combination of medical and behavioral strategies . However , some recommended therapies are under-utilized in clinical setting s , and the majority of patients with hip and knee OA are overweight and physically inactive . Consequently , interventions at the provider-level and patient-level both have potential for improving outcomes . This manuscript describes two ongoing r and omized clinical trials being conducted in two different health care systems , examining patient-based and provider-based interventions for managing hip and knee OA in primary care . Methods / Design One study is being conducted within the Department of Veterans Affairs ( VA ) health care system and will compare a Combined Patient and Provider intervention relative to usual care  among n = 300 patients ( 10 from each of 30 primary care providers ) . Another study is being conducted within the Duke Primary Care Research Consortium and will compare Patient Only , Provider Only , and Combined ( Patient + Provider ) interventions relative to usual care  among n = 560 patients across 10 clinics . Participants in these studies have clinical and / or radiographic evidence of hip or knee osteoarthritis , are overweight , and do not meet current physical activity guidelines . The 12-month , telephone-based patient intervention focuses on physical activity , weight management , and cognitive behavioral pain management . The provider intervention involves provision of patient-specific recommendations for care ( e.g. , referral to physical therapy , knee brace , joint injection ) , based on evidence -based guidelines . Outcomes are collected at baseline , 6-months , and 12-months . The primary outcome is the Western Ontario and McMasters Universities Osteoarthritis Index ( self-reported pain , stiffness , and function ) , and secondary outcomes are the Short Physical Performance Test Protocol ( objective physical function ) and the Patient Health Question naire-8 ( depressive symptoms ) . Cost effectiveness of the interventions will also be assessed . Discussion Results of these two studies will further our underst and ing of the most effective strategies for improving hip and knee OA outcomes in primary care setting s . Trial registration NCT01130740 ( VA ) ; NCT 01435109 ( NIH OBJECTIVE To assess the effectiveness of physical therapy , given either as an individually attended treatment or in a small group format , in terms of pain , physical function , and health related quality of life for patients with osteoarthritis ( OA ) of the knee . METHODS After 2 baseline assessment s , 126 patients were r and omized into one of 3 allocation arms : individual treatments ( n = 43 ) , small group format program ( n = 40 ) , and waiting list control ( n = 43 ) . After re assessment at 8 weeks , patients allocated to waiting list control were r and omized into one of the 2 active treatment arms . Assessment s included both self-report measures ( WOMAC , SF-36 ) and objective measures of physical performance ( gait analysis and muscle strength ) . RESULTS Both physical therapy treatment allocations result ed in significant improvements in pain , physical function , and health related quality of life above the control group ( st and ardized response mean 0.36 to 0.65 ) . Improvements in the self-report measures were substantiated by significant correlated improvements in knee extensor strength and fast walking speed ( rho 0.36 - 0.42 ) . There were no significant differences in effectiveness between the 2 physical therapy allocations for any of the measured outcomes . Improvements gained were maintained for at least 2 months . Responsiveness to treatment was modified by loss of medial joint space width , the interaction being significant for physical function , gait , and knee extensor strength . CONCLUSION Physical therapy , either as an individually delivered treatment or in a small group format , is an effective intervention for patients with knee OA . Responsiveness to this 8 week intervention was modified by loss of medial joint space width OBJECTIVE To investigate whether manual therapy has particular benefit in subgroups of patients defined on the basis of hip function , range of joint motion , pain and radiological deterioration . METHODS The study was performed in the out-patient clinic of physical therapy of a large hospital . Data on 109 patients with OA of the hip ( clinical ACR criteria ) participating in a r and omized clinical trial on the effects of manual therapy were used . The outcomes for hip function ( Harris hip score ) , range of joint motion ( ROM ) and pain ( VAS ) were compared for specific subgroups . Subgroups were assigned by the median split method . The interaction effect between subgroup and treatment was tested using multiple regression analysis . RESULTS No differences were observed in the effect of manual therapy  in specific subgroups of patients defined on the basis of baseline levels of hip function , pain and ROM . On the basis of radiological grading of osteoarthritis ( OA ) , we found that patients with severe radiological grading of OA had significantly worse outcome on ROM as a result of manual therapy than patients with mild or moderate radiological grading of OA . CONCLUSION A significant interaction effect was found for only 1 out of 12 hypotheses investigated . Therefore , we conclude that there is no evidence for the particular benefit of manual therapy in subgroups of patients
On balance of the limited evidence , the 40 m self-paced test was the best rated walk test , the 30 s-chair st and test and timed up and go test were the best rated sit to st and tests , and the Stratford battery , Physical Activity Restrictions and Functional Assessment System were the best rated multi-activity measures .
OBJECTIVES To systematic ally review the measurement properties of performance-based measures to assess physical function in people with hip and /or knee osteoarthritis ( OA ) .