twenty - nine participants ( 16 females and 13 males ) aged 67.70  6.07 participated in this study . participants were recruited from various pa programs that focused on older adults ( ages 60 + ) in the community . height , weight , and waist circumference were assessed in light clothing and without shoes to the nearest 0.5 cm and 0.1 kg , respectively . each participant completed a physical activity readiness questionnaire ( par - q ) . a positive response to one or more of the seven par - q questions excluded a participant from the study . the par - q is widely used as a screening tool for all pa participation . the par - q is used in canada and has been adopted widely throughout the united states ( adams , 1999 ; thomas , reading , & shephard , 1992 ) . prior to participation , all participants had the research study and its potential risks and benefits explained fully before providing written informed consent . = standard deviation ; cm = centimeters ; kg = kilograms ; bmi = body mass index ; kgm = kilogram per meters squared ; ms = meters per second . the dual mode actical accelerometer ( respironics inc . , bend , oregon ) , yamax sw-200 ( yamax corporation , tokyo , japan ) , omron hj-112 ( omron healthcare , vernon hills , illinois ) , and walk4life elite ( walk4life , inc , plainfield , illinois ) were used to estimate steps registered by participants . the yamax sw-200 is a spring - lever pedometer that includes a step counter , which accurately counts steps while walking , hiking , jogging , or running . a more detailed description of the yamax sw-200 and its functions have been provided in previous research ( crouter , schneider , & bassett , 2005 ) . the yamax sw-200 pedometer has also been the pedometer of choice when examining step count accuracy in older adults who either reside in assisted - living facilities or are community - dwelling ( bergman et al . , 2008 ; cyarto et al . , 2004 ; grant et al . , 2008 ; storti et al . , the walk4life elite is a spring - lever pedometer that includes a step counter , activity time , and distance displayed in miles walked . the omron hj-112 is a piezoelectric pedometer that records number of steps during walking and jogging activities . a more detailed description of the omron hj-112 and its functions have been described in previous research ( hasson , haller , pober , staudenmayer , & freedson , 2009 ) . very limited research is available on the walk4life elite and omron hj-112 step count accuracy during walking at low treadmill speeds and no research is available involving community - dwelling older adults . all pedometers used in this study were checked for calibration using a shake test ( vincent & sidman , 2003 ) . these pedometers have been some of the more commonly used in recent research ( abel et al . , 2011 ; bassett et al . , 2008 ; feito , bassett , & thompson , 2012 ; hasson et al . , 2009 ) . bend , oregon ) is a dual mode accelerometer ( registers accelerometer counts and step counts ) that uses a piezoelectric accelerometer mechanism . a more detailed description of the actical and its functions has been described in previous research ( esliger et al . the few studies that are available on the dual mode actical step count function ( johnson , meltz , hart , schmudlach , clarkson , & broman , 2014 ; esliger et al . 2007 ; feito , bassett , & thompson , 2012 ; feito , bassett , thompson , & tyo , 2012 ) have not included older adults ( age  60 ) . the actical accelerometers used in this study were checked using manufacturer - recommended hardware and software , and calibrated if necessary . at the end of each test , accelerometer data were downloaded using manufacturer - recommended hardware and software . the actical step counts and three pedometer step counts were recorded while walking on an indoor track and walking on a motor - driven treadmill at various speeds . directly observed step counts ( recorded with a hand - tally device ) served as the criterion . the testing took place over the course of 6.69  3.4 days , and each person wore the same pair of shoes for all trials . all devices were worn concurrently on an elastic belt on their right waist / hip , following the manufacturer s recommendations for placement on the body , during testing . participants were first asked to complete a 200-m walk around an indoor track ( field setting ) . participants walked at a self - selected pace while two investigators using hand - tally counters walked behind the participant , to avoid influencing pace . the amount of time it took to complete the 200-m walk was measured to calculate each participant s self - selected pace ( schneider , crouter , lukajic , & bassett , 2003 ; storti , pettee , brach , talkowski , richardson , & kriska , 2007 ) . at the end of the 200-m walk , the participants were told to stand still , and the number of steps detected by each pedometer was then recorded . participants then walked on a treadmill at three different speeds : 0.67 ms , 0.894ms , and 1.12 ms for 5 min at each speed with treadmill gradient set at 0 . these treadmill speeds have been used previously to examine activity monitor accuracy in community - dwelling older adults ( grant et al . , 2008 ) and healthy adults ( crouter , schneider , karabulut , & bassett , 2003 ; feito , bassett , & thompson , 2012 ; le masurier , lee , & tudor - locke , 2004 ) . the participants received instructions for walking on the treadmill and were allowed time to adapt to the various walking speeds . before each bout , participants stood still ( straddling the treadmill belt ) for a 2-min washout period . this was performed to ensure that any steps detected by the accelerometer before the official bout were not considered in the analysis ( le masurier & tudor - locke , 2003 ) . the 2-min washout period was repeated between each bout and after the last one . at the end of each bout , the number of steps detected by each pedometer was recorded and the units were reset to zero before the subsequent bouts . observed steps were counted by two researchers , using hand - tally counters , with the average of the two being recorded if counted steps differed . one - way within - participants repeated measure analyses of variance ( anovas ) were used to assess significant differences between actual steps taken and estimated step counts registered by the activity monitors for all four conditions ( self - selected pace walking and three treadmill walking speeds ) . post hoc analyses for the anova procedures were performed if significance were found using pairwise comparisons with bonferroni adjustments . the one - way anova for treadmill walking speed at 1.12 ms only used 28 participants data due to 1 participant unable to walk at this speed . mean absolute percent error ( mape ) was calculated between observed steps and actical / pedometer - determined steps  mape = ( [ actical / pedometer steps observed steps ) / observed steps ]  100and was used as another outcome measure . a smaller mape represents better accuracy , and less than 3% is considered acceptable pedometer accuracy ( bassett et al . , 2008 ) . altman plots were also used to demonstrate level of agreement between criterion measures and estimated step counts registered by the activity monitors during self - selected pace walking and walking at three different treadmill speeds ( bland & altman , 1986 ) . statistical analyses were performed using spss 18.0 ( statistical package for the social sciences , inc , chicago , illinois ) . for all analyses , a p value < .05 was used to indicate statistical significance . means and standard deviations were reported for descriptive data . twenty - nine participants ( 16 females and 13 males ) aged 67.70  6.07 participated in this study . participants were recruited from various pa programs that focused on older adults ( ages 60 + ) in the community . height , weight , and waist circumference were assessed in light clothing and without shoes to the nearest 0.5 cm and 0.1 kg , respectively . each participant completed a physical activity readiness questionnaire ( par - q ) . a positive response to one or more of the seven par - q questions excluded a participant from the study . the par - q is widely used as a screening tool for all pa participation . the par - q is used in canada and has been adopted widely throughout the united states ( adams , 1999 ; thomas , reading , & shephard , 1992 ) . prior to participation , all participants had the research study and its potential risks and benefits explained fully before providing written informed consent . = standard deviation ; cm = centimeters ; kg = kilograms ; bmi = body mass index ; kgm = kilogram per meters squared ; ms = meters per second . bend , oregon ) , yamax sw-200 ( yamax corporation , tokyo , japan ) , omron hj-112 ( omron healthcare , vernon hills , illinois ) , and walk4life elite ( walk4life , inc , plainfield , illinois ) were used to estimate steps registered by participants . the yamax sw-200 is a spring - lever pedometer that includes a step counter , which accurately counts steps while walking , hiking , jogging , or running . a more detailed description of the yamax sw-200 and its functions have been provided in previous research ( crouter , schneider , & bassett , 2005 ) . the yamax sw-200 pedometer has also been the pedometer of choice when examining step count accuracy in older adults who either reside in assisted - living facilities or are community - dwelling ( bergman et al . , 2008 ; cyarto et al . , 2004 ; grant et al . , 2008 ; storti et al . , the walk4life elite is a spring - lever pedometer that includes a step counter , activity time , and distance displayed in miles walked . the omron hj-112 is a piezoelectric pedometer that records number of steps during walking and jogging activities . a more detailed description of the omron hj-112 and its functions have been described in previous research ( hasson , haller , pober , staudenmayer , & freedson , 2009 ) . very limited research is available on the walk4life elite and omron hj-112 step count accuracy during walking at low treadmill speeds and no research is available involving community - dwelling older adults . all pedometers used in this study were checked for calibration using a shake test ( vincent & sidman , 2003 ) . these pedometers have been some of the more commonly used in recent research ( abel et al . , 2011 ; bassett et al . , 2008 ; feito , bassett , & thompson , 2012 ; hasson et al . , 2009 ) . bend , oregon ) is a dual mode accelerometer ( registers accelerometer counts and step counts ) that uses a piezoelectric accelerometer mechanism . a more detailed description of the actical and its functions has been described in previous research ( esliger et al . , 2007 ; heil , 2006 ) . the few studies that are available on the dual mode actical step count function ( johnson , meltz , hart , schmudlach , clarkson , & broman , 2014 ; esliger et al . 2007 ; feito , bassett , & thompson , 2012 ; feito , bassett , thompson , & tyo , 2012 ) have not included older adults ( age  60 ) . the actical accelerometers used in this study were checked using manufacturer - recommended hardware and software , and calibrated if necessary . at the end of each test the actical step counts and three pedometer step counts were recorded while walking on an indoor track and walking on a motor - driven treadmill at various speeds . directly observed step counts ( recorded with a hand - tally device ) served as the criterion . the testing took place over the course of 6.69  3.4 days , and each person wore the same pair of shoes for all trials . all devices were worn concurrently on an elastic belt on their right waist / hip , following the manufacturer s recommendations for placement on the body , during testing . participants were first asked to complete a 200-m walk around an indoor track ( field setting ) . participants walked at a self - selected pace while two investigators using hand - tally counters walked behind the participant , to avoid influencing pace . the amount of time it took to complete the 200-m walk was measured to calculate each participant s self - selected pace ( schneider , crouter , lukajic , & bassett , 2003 ; storti , pettee , brach , talkowski , richardson , & kriska , 2007 ) . at the end of the 200-m walk , the participants were told to stand still , and the number of steps detected by each pedometer was then recorded . participants then walked on a treadmill at three different speeds : 0.67 ms , 0.894ms , and 1.12 ms for 5 min at each speed with treadmill gradient set at 0 . these treadmill speeds have been used previously to examine activity monitor accuracy in community - dwelling older adults ( grant et al . , 2008 ) and healthy adults ( crouter , schneider , karabulut , & bassett , 2003 ; feito , bassett , & thompson , 2012 ; le masurier , lee , & tudor - locke , 2004 ) . the participants received instructions for walking on the treadmill and were allowed time to adapt to the various walking speeds . before each bout , participants stood still ( straddling the treadmill belt ) for a 2-min washout period . this was performed to ensure that any steps detected by the accelerometer before the official bout were not considered in the analysis ( le masurier & tudor - locke , 2003 ) . the 2-min washout period was repeated between each bout and after the last one . at the end of each bout , the number of steps detected by each pedometer was recorded and the units were reset to zero before the subsequent bouts . observed steps were counted by two researchers , using hand - tally counters , with the average of the two being recorded if counted steps differed . one - way within - participants repeated measure analyses of variance ( anovas ) were used to assess significant differences between actual steps taken and estimated step counts registered by the activity monitors for all four conditions ( self - selected pace walking and three treadmill walking speeds ) . post hoc analyses for the anova procedures were performed if significance were found using pairwise comparisons with bonferroni adjustments . the one - way anova for treadmill walking speed at 1.12 ms only used 28 participants data due to 1 participant unable to walk at this speed . mean absolute percent error ( mape ) was calculated between observed steps and actical / pedometer - determined steps  mape = ( [ actical / pedometer steps observed steps ) / observed steps ]  100and was used as another outcome measure . a smaller mape represents better accuracy , and less than 3% is considered acceptable pedometer accuracy ( bassett et al . , 2008 ) . altman plots were also used to demonstrate level of agreement between criterion measures and estimated step counts registered by the activity monitors during self - selected pace walking and walking at three different treadmill speeds ( bland & altman , 1986 ) . statistical analyses were performed using spss 18.0 ( statistical package for the social sciences , inc , chicago , illinois ) . for all analyses , a p value < .05 was used to indicate statistical significance . means and standard deviations were reported for descriptive data . there was no statistical difference between any of the activity monitors step counts and actual steps taken during self - selected pace walking , wilks s  = 0.76 , f(4 , 25 ) = 2 , p = .13 , and all mape values were acceptable ( 2.62% ) . during treadmill walking at 0.67 ms , all the activity monitors step counts were significantly different from actual steps taken , wilks s  = 0.16 , f(4 , 25 ) = 33.58 , p < .001 . post hoc analysis revealed that the three pedometers and accelerometer step counts were significantly different ( all p < .001 ) and all mape were unacceptable ( 38.06% ) . during treadmill walking at 0.894 ms , activity monitors step counts were significantly different from actual steps taken , wilks s  = 0.27 , f(4 , 25 ) = 16.55 , p < .001 . post hoc analysis revealed that the omron hj-112 pedometer step counts were the only ones not statistically different from actual steps taken ( p = .16 ) , and the mape was 3.5% . the yamax sw-200 and walk4life pedometers step counts were both significantly different at p < .001 , while the actical accelerometer step counts were significantly different at p = .002 . during treadmill walking at 1.12 ms speed , activity monitors step counts were significantly different from actual steps taken , wilks s  = 0.42 , ( 4 , 24 ) = 8.24 , p < .001 . post hoc analysis revealed that the yamax sw-200 step counts were significantly different from actual steps taken ( p = .012 ) and had an unacceptable mape value = 11.48% . all other devices step counts were not significantly different from actual steps taken and had acceptable mape values < 2.58% . post hoc power estimates = 1 for anovas examining differences between actual steps taken and steps registered by activity monitors at treadmill walking speeds 0.671 ms and 0.894 ms . post hoc power estimates were .99 and .92 for anovas examining differences between actual steps taken and steps registered by activity monitors at treadmill walking speed 1.12 ms and self - selected pace walking , respectively . table 2 presents the mape values for all activity monitors during self - selected pace and treadmill walking . altman plots for each activity monitors step count results for self - selected pace and treadmill walking . table 3 presents the estimated step counts registered for all activity monitors during self - selected pace and treadmill walking . mean absolute percentage error ( mape ) in self - selected pace and treadmill walking . note . om = omron hj-112 model ; ym = yamax sw-200 model ; w4l = walk4life elite model ; ms = meters per second on treadmill . altman plots depicting error scores ( actual steps  estimated step ) for the yamax sw-200 during ( a ) self - selected pace , ( b ) treadmill walking at 0.67 ms , ( c ) treadmill walking at 0.894 ms , and ( d ) treadmill walking at 1.12 ms . note . altman plots depicting error scores ( actual steps  estimated step ) for the walk4life elite during ( a ) self - selected pace , ( b ) treadmill walking at 0.67 ms , ( c ) treadmill walking at 0.894 ms , and ( d ) treadmill walking at 1.12 ms . note . altman plots depicting error scores ( actual steps  estimated step ) for the omron hj-112 during ( a ) self - selected pace , ( b ) treadmill walking at 0.67 ms , ( c ) treadmill walking at 0.894 ms , and ( d ) treadmill walking at 1.12 ms . note . altman plots depicting error scores ( actual steps  estimated step ) for the actical during ( a ) self - selected pace , ( b ) treadmill walking at 0.67 ms , ( c ) treadmill walking at 0.894 ms , and ( d ) treadmill walking at 1.12 ms . note . step counts registered by four different devices , for overground walking at a self - selected pace ( ssp ) and treadmill walking at three speeds . note . om = omron hj-112 model ; ym = yamax sw-200 model ; w4l = walk4life elite model ;  = standard deviation ; ms = meters per second on treadmill . the purpose of this study was to examine the step count function of pedometers ( spring - lever vs. piezoelectric ) and an accelerometer in a group of community - dwelling older adults during self - selected pace and treadmill walking in comparison with actual steps taken . all activity monitors performed exceptionally well for walking around an indoor track at self - selected pace . there was no statistical difference between the activity monitors step counts and actual steps taken during self - selected pace walking and all mape values were < 3% . ( 2008 ) for the yamax sw-200 who reported < 2% mape values in a group of community - dwelling older adults ( mage = 72 ) with similar self - selected pace values during an outdoor walking protocol . conversely , cyarto et al . ( 2004 ) reported higher mape values for the yamax in a group of community - dwelling older adults ( mage = 71 ) walking a 13-m course with self - selected pace values ranging from 0.95 ms to 1.61 ms . ( 2008 ) also reported higher mape values for the yamax sw-200 in a group of community - dwelling older adults ( mage = 79 ) during a 100-step walking test . the reported self - selected pace values ranged from < 0.80 ms to > 1.0 ms , which were slower than the values in the current study . 2008 ) reported a low relationship between the yamaxsw-200 and actual steps taken over a 161-m walking trial by older adults ( mage = 77 ) living in assisted - living facilities . the reported average self - selected pace of participants in their study was much slower than the participants in the current study . this supports the notion that older adults who reside in an assisted - living facility walk at a slower pace than community - dwelling older adults . cyarto et al . also demonstrated that community - dwelling older adults walk at a faster pace when compared with older adults residing in a nursing home . ( 2004 ) also reported acceptable mape values for the walk4life elite pedometer for self - selected pace walking in adults . ( 2011 ) found that the omron hj-112 did not have superior step counting accuracy at self - selecting walking speed in adults . the actical accelerometer self - selected walking results from this study were similar to those of authors ( 2014 ) who reported no differences between actual steps and actical - recorded steps while walking around a track in young adults . previous studies that have examined the actical step count function in children and adults in a controlled setting ( treadmill walking ) have shown it to perform exceptionally well at walking speeds > 1.12 ms and 2.19 ms ( authors , 2014 ; colley et al . , 2013 ; esliger et al . 2007 ; feito , bassett , & thompson , 2012 ; feito et al . , 2012 ) . our results suggest that this is also true for older adults in a free - living setting as well . the actical accelerometer , walk4life elite , and omron hj-112 pedometers performed well for walking on a motorized treadmill at 1.12 ms speed , and mape values were < 3% . the actical treadmill walking at 1.12 ms results from this study are supported by feito , bassett , and thompson ( 2012 ) and feito et al . ( 2012 ) , who reported no differences between actual steps and actical - recorded steps while walking on a treadmill at 1.12 ms in normal and overweight adults . previous research ( crouter et al . , 2003 ; hasson et al . , 2009 ; melanson et al . , 2004 ) has shown the walk4life elite and omron hj-112 pedometers to accurately detect steps at this treadmill speed in adults . 2011 ) reported that the omron hj-112 did not accurately detect steps at this treadmill speed in adults . our results support previous findings regarding the yamax sw-200 susceptibility in registering steps while walking at this treadmill speed in adults and older adults ( colley et al . , 2013 ; feito , bassett , & thompson , 2012 ; grant et al . , 2008 ; horvath , taylor , marsh , & kriellaars , 2007 ; melanson et al . , 2004 ) . the actical step count function did not perform well while walking on a motorized treadmill at 0.67 ms and 0.894 ms speeds and had unacceptable mape values . ( 2012 ) , who reported a significant difference between actual steps and actical - recorded steps while walking on a treadmill at 0.67 ms in adults . previous studies have demonstrated the actical step count function susceptibility to walking at similar slow speeds on a treadmill for children and adults . it appears that regardless of age group , the actical step count function may be susceptible to registering steps at slow treadmill walking speeds 1.05 ms ( authors , 2014 ; colley et al . these walking speeds may be indicative of older adults who reside in assisted - living facilities or nursing homes ( bergman et al . , 2008 ; cyarto et al . , all pedometer - registered steps were significantly different from actual steps during treadmill walking at 0.67 ms and had unacceptable mape values . ( 2008 ) , who reported a significant difference for the yamax sw-200 pedometer in older adults at the same treadmill walking speeds . this relationship has also been previously shown in the adult population as well for both the yamax sw-200 and walk4life elite pedometers ( colley et al . , 2013 ; crouter et al . , 2003 ; feito , bassett , & thompson , 2012 ; melanson et al . , 2004 ) . during treadmill walking at 0.894 ms , the omron hj-112 pedometer was the only activity monitor with registered steps not significantly different from actual steps and an mape value slightly above acceptability ( 3.5% ) . this is the first study to demonstrate this relationship in older adults , and it is supported by authors ( 2014 ) who reported a similar relationship in young adults at this treadmill walking speed . these results support previous research that indicated that piezoelectric pedometers are more accurate in detecting steps at slower walking speeds in normal , overweight , and obese adults when compared with spring - lever pedometers ( crouter et al . , 2005 ; melanson et al . , 2004 this walking speed was indicative of some older adults , who resided either in assisted - living facilities or nursing homes ( bergman et al . the yamax sw-200 and walk4life elite pedometer - registered steps were significantly different from observed steps during treadmill walking at 0.894 ms . results are inconclusive for the walk4life elite pedometer at this treadmill speed in adults ( crouter et al . , 2003 ; melanson et al . , 2004 ) and the yamax sw-200 has shown similar susceptibility in both the older adult and adult populations ( authors , 2014 ; colley et al . , 2013 ; feito , bassett , & thompson , 2012 ; grant et al . , 2008 ; horvath et al . to gain a better understanding of the relationship between pa and health for the aging population , epidemiologists , exercise scientists , clinicians , and behavioral researchers must rely on objective measures of pa with supportive evidence specific to that population of interest . all activity monitors provided valid estimates of step counts during self - selected pace walking . the walk4life elite ( spring - lever ) , omron hj-112 ( piezoelectric ) , and actical accelerometer provided valid estimates of step counts walking at a constant speed of 1.12 ms . the omron hj-112 pedometer was the only monitor that provided valid estimates of step counts walking at a constant speed of 0.894 ms . it is recommended that pedometer and accelerometer be used in tandem ( if feasible ) to capture ambulatory behavior in community - dwelling older adults walking at this pace if the focus is on capturing steps , intensity , duration , and frequency of pa ( authors , 2014 ; hooker et al . , none of the activity monitors provided valid estimates of step counts walking at a constant speed of 0.67 ms , which may be indicative of older adults residing in an assisted - living facility . it is recommended that a different device be used to capture ambulatory behavior in this group such as the step watch 3 ( bergman et al . , 2008 ) . this study provides some preliminary evidence of validity for the actical accelerometer , walk4life elite , and omron hj-112 pedometers step count function in community - dwelling older adults where studies have been distinctly lacking .