StepWatchTM Activity Monitor Research Articles

Concurrent validity and reliability of an activity monitoring for rehabilitation (AMoR) platform for step counting and sitting/lying time in post-stroke individuals

ABSTRACT Background Objective and reliable measurements to investigate daily behavior patterns in people with stroke could help therapeutic interventions after a stroke. Objective To evaluate whether the Activity Monitoring for Rehabilitation (AMoR) platform has adequate concurrent validity and reliability for step counting and time spent sitting/lying in people post-stroke and to investigate its percentage accuracy for step counting at different walking speeds. Methods Cross-sectional observational study. Fifty chronic post-stroke subjects used the AMoR platform and SAM simultaneously while a Video camera recorded the same activities during clinical trials. Spearman’s correlation coefficient, the mean absolute percentage error, the intraclass correlation coefficient and Bland-Altman plot analyses were used to estimate the validity and reliability of the AMoR platform and StepWatchTM Activity Monitor (SAM). The accuracy percentage was calculated for each device and plotted as a function of the walking speed during the 10-meter walk test (10MWT). Results There was a very high correlation for step counting in all tests and a high correlation for time spent sitting/lying. The mean absolute percentage error values remained below 4% for step counting and time sitting/lying. The AMoR platform also showed excellent reliability for step counting and sitting/lying time, with values within the limit of agreement in the Bland-Altman plots. A high percentage of accuracy for step counting in the AMoR platform was observed during the 10MWT. Conclusion The AMoR platform is valid and reliable for step counting and time spent sitting/lying, with a high percentage of accuracy at different walking speeds in the post-stroke population.

How shoulder immobilization influences daily physical activity \u2013 an accelerometer based preliminary study

BackgroundTo investigate the influence of shoulder immobilization on daily physical activity.IntroductionThe harmful effect of sedentary behavior does not receive much attention in orthopedic surgery even though immobilization, especially of the lower extremity, has been associated with reduced physical activity. Immobilization of the shoulder is common after reconstructive shoulder surgery and could also potentially lead to reduced physical activity and have a negative effect on a patient’s general health.MethodTwenty-one healthy volunteers were immobilized in an orthosis (DJO Ultrasling III) for 10 h on two consecutive days. In the following week, activity was measured on the same days without the orthosis. Activity including gait cycles per minute and total gait cycles per day was measured by accelerometer based step count StepWatchTMActivity Monitor. Average age was 26 +/− 3 years. A questionnaire was administered to evaluate subjective activity.ResultsParticipants wearing the shoulder orthosis were significantly less active than without immobilization by 2227.5 gait cycles/day (5501.2 with SO, 7728.7 without SO). Also, significantly more time in sedentary behavior occurred (< 400 steps/h) when the shoulder was immobilized. Patients were significantly more active without shoulder orthosis in medium level activities (800–999 steps/h). Differences for low (400–799 steps/h) and high activity levels (> 1000 steps/h) were not statistically significant. Subjective limitations while wearing the orthosis were graded at 2.343 on a scale of 0–4.ConclusionResults of this study show that even in young, healthy volunteers immobilization of the shoulder in an orthosis for 2 days leads to significantly reduced activity levels. A negative influence on general health, especially in older patients who are immobilized for up to 6 weeks, can potentially occur. Promoting physical activity during the immobilization period should be part of rehabilitation after injuries/surgery of the shoulder.Trial registrationRetrospectively registered in DRKS (DRKS00017636).

Are novel outcome measures for Charcot–Marie–Tooth disease sensitive to change? The 6-minute walk test and StepWatch™ Activity Monitor in a 12-month longitudinal study

Charcot–Marie–Tooth (CMT) is the most common inherited neuropathy, yet has no available pharmacological therapy. Past pharmacotherapy trials failed to provide positive results, possibly due to a poor choice of outcome measures. We previously performed a study in which we validated the 6-minute walk test and StepWatch™ Activity Monitor in CMT. The aim of the current study was to determine if these outcome measures are sensitive to change over a 12-month period. In this longitudinal multicenter study, 149 out of 169 initially enrolled patients were re-evaluated after 12 months using the 6-minute walk test, StepWatch™ Activity Monitor and other outcome measures commonly adopted in CMT disease. Statistical analysis showed a worsening of the CMT-Neuropathy Score (p < 0.05), strength of distal muscles measured by myometry (p < 0.05) and StepWatch™ Activity Monitor outputs (p < 0.05). The 10 meter walking test (p > 0.05), muscular strength as detected by clinical evaluation (p > 0.05), 6-minute walk test (p > 0.05), pain (p > 0.05) and quality of life (p > 0.05) showed no change. In the current study, patients showed clinical worsening over 12 months, confirmed by a reduction of activity as detected by StepWatch™ Activity Monitor. The 6-minute walk test failed to detect change.

A prospective randomized comparison of the minimally invasive direct anterior and the transgluteal approach for primary total hip arthroplasty

BackgroundThe presented prospective randomized controlled single-centre study compares the clinical outcome up to 12 months after total hip arthroplasty using a minimally invasive single-incision direct anterior (DAA) and a direct transgluteal lateral approach.MethodsA total of 123 arthroplasties were evaluated utilizing the Harris Hip Score (HHS), the extra short musculoskeletal functional assessment questionnaire (XSFMA), the Short Form 36 (SF-36) health survey, a Stepwatch™ Activity Monitor (SAM), and a timed 25 m foot walk (T25-FW). Postoperative x-ray images after THA were reviewed to determine inclination and stem positioning.ResultsAt final follow-up, the XSFMA functional index scores were 10.3 (anterior) and 15.08 (lateral) while the bother index summed up to a score of 15.8 (anterior) and 21.66 (lateral) respectively, thus only differing significantly for the functional index (p = 0.040 and p = 0.056). The SF-36 physical component score (PCS) was 47.49 (anterior) and 42.91 (lateral) while the mental component score (MCS) summed up to 55.0 (anterior) and 56.23 (lateral) with a significant difference evident for the PCS (p = 0.017; p = 0.714). Patients undergoing THA through a DAA undertook a mean of 6402 cycles per day while those who had undergone THA through a transgluteal approach undertook a mean of 5340 cycles per day (p = 0.012). Furthermore, the obtained outcome for the T25-FW with 18.4 s (anterior) and 19.75 s (lateral) and the maximum walking distance (5932 m and 5125 m) differed significantly (p = 0.046 and p = 0.045). The average HHS showed no significant difference equaling 92.4 points in the anterior group and 91.43 in the lateral group (p = 0.477). The radiographic analysis revealed an average cup inclination of 38.6° (anterior) and 40.28° (lateral) without signs of migration.ConclusionIn summary, our outcomes show that after 1 year THA through the direct anterior approach results in a higher patient activity compared to THA utilizing a transgluteal lateral approach while no differences regarding hip function are evident.Trial registrationDRKS00014808 (German Clinical Trial Register DRKS); date of registration: 31.05.2018.

Objectively measured versus self-reported physical activity in children and adolescents with cancer

ObjectiveExisting research recognizes low levels of physical activity in pediatric patients with cancer, but much uncertainty exists about their capability to self-reflect physical activity levels. The objective of this study was to compare results of subjective self-reports and objective accelerometers regarding levels of daily walking as well as moderate-to-vigorous physical activities.MethodsResults of the objective assessment tool StepWatchTM Activity Monitor and self-reporting with a standardized questionnaire were compared in 28 children and adolescents during cancer treatment.ResultsThe patients were 13.8±2.8 years of age and 3.4±2.0 months after cancer diagnosis. The Bland-Altman plots indicated a fairly symmetrical under- and over-estimation for daily minutes of walking with the limits of agreement ranging from -100.8 to 87.3 min (d = -6.7 min). Mean difference for moderate-to-vigorous physical activity was almost zero but limits of agreement are ranging from -126.8 to 126.9 min. The comparison for the days with at least 60 min of moderate-to-vigorous physical activity showed a marked difference with 3.0±2.6 self-reported days versus only 0.1±0.4 measured days.ConclusionsThese findings suggest that physical activity in pediatric cancer patients should preferably be assessed with objective methods. Greater efforts are needed to implement supervised exercise interventions during treatment incorporating methods to improve self-reflection of physical activity.

Differently designed playgrounds and preschooler’s physical activity play

ABSTRACTNew playground concepts – favouring natural play characteristics – emerge. The aim of our free play study is to explore the relation between newly established natural playgrounds and the widely spread contemporary ones in terms of physical activity levels. The playground features differ in vegetation, topography, size and play equipment. The children’s locomotive activity was measured with the StepWatch™ Activity Monitor – a pedometer. Research with known groups of preschool children on urban playgrounds should serve a future transfer of results to institutional play areas. Within this pilot study, results indicate that there is no significant difference in mean locomotive activity during free play on diverse playgrounds. However, results show high variability of activity between the playgrounds in terms of active children and rather sedentary ones. In conclusion, kindergarten environments should be more diverse incorporating elements of nature and contemporary playgrounds to serve all levels of activity.

Objectively-measured sedentary time and cardiometabolic health in adults with severe obesity

It is unknown whether sedentary behavior is independently associated with the cardiometabolic health of adults with severe obesity. Additionally, there is debate regarding how best to derive meaningful indices of sedentary time (ST) from activity monitor data. A convenience sample of adults with severe obesity (N=927; 79% female, median age 45y, median body mass index (BMI) 46kg/m2) completed a research assessment at one of ten US hospitals in 2006–2009 prior to bariatric surgery. Cardiometabolic health was assessed via physical measures, fasting blood samples and medication use. Indices of ST were derived from StepWatch™ activity monitor data with minimum bout durations of 1min, 10min and 30min. Cross-sectional associations were examined. Median (25th, 75th percentile) ST was 9.3h/d (8.1, 10.5) in ≥1min bouts, 6.5h/d (5.2, 8.0) in ≥10min bouts, or 3.2h/d (2.1, 4.5) in ≥30min bouts. Associations with ST were generally strongest with the ≥10min bout duration. Independent of moderate-to-vigorous intensity physical activity, BMI and other potential confounders, 1h/day ST in ≥10min bouts was associated with higher odds of diabetes by 15% (95%CI: 1.05–1.26), metabolic syndrome by 12% (95%CI: 1.01–1.24) and elevated blood pressure by 14% (95%CI: 1.02–1.26), and was associated with 1.4cm (95%CI: 0.9–1.9) larger waist circumference. Findings indicate the importance of considering ST as a distinct health risk among adults with severe obesity, and suggest a 10min minimum duration may be preferable to 1min or 30min for establishing ST from activity monitor data.

Walking activity of children with cerebral palsy and children developing typically: a comparison between the Netherlands and the United States

Purpose: To compare walking activity of children with and without cerebral palsy (CP) between the Netherlands and the United States. Methods: A cross-sectional analysis on walking activity data from an international retrospective comparison study including a convenience sample of 134 walking children aged 7–12 years with spastic CP, classified as Gross Motor Function Classification System (GMFCS) level I (N = 64), II (N = 49) or III (N = 21), and 223 typically developing children (TDC) from the Netherlands and the United States. Walking activity was assessed during a one-week period using a StepWatch™ activity monitor. Outcomes were the daily number of strides, daily time being inactive and spent at low (0–15 strides/min), moderate (16–30 strides/min) and high stride rate (31–60 strides/min). Walking activity was compared between countries using multiple linear regression analyses. Results: Walking activity of TDC was not significantly different between countries. Compared to their American counterparts, Dutch children in GMFCS level I and II showed less walking activity (p < 0.05), whereas Dutch children in GMFCS level III showed more walking activity (p < 0.05). Conclusion: The absence of differences in walking activity between Dutch and American TDC, and the presence of differences in walking activity between Dutch and American children with CP suggest that between-country differences affect walking activity differently in children with CP.Implications for RehabilitationPhysical activity of children with CP should be promoted in both the United States and the Netherlands.The between-country differences in walking activity illustrate that apart from the severity of the CP walking activity seems to be influenced by environmental aspects.In the promotion of physical activity, practitioners should pay attention to environmental barriers that families may experience for increasing physical activity.

A Pilot Walking Program Promotes Moderate-Intensity Physical Activity during Pregnancy

Walking may be a strategy for increasing moderate-intensity physical activity (MPA) during pregnancy. This study aimed to promote MPA among overweight and obese pregnant women, via walking, and to evaluate the effect of the intervention on maternal and birth outcomes. Thirty-seven overweight or obese pregnant women were randomly assigned to a walking intervention or control group. Anthropometric and objective PA (StepWatch™ Activity Monitor) data were collected for four 1-wk periods: weeks 10-14 (V1), weeks 17-19 (V2), weeks 27-29 (V3), and weeks 34-36 (V4) of gestation. Participants provided information about maternal and birth outcomes. A cadence of ≥ 80 steps per minute was defined as MPA, and "meaningful walking" was defined as moderate walking in ≥ 8-min bouts. ANOVA was used to determine the differences in walking amount and meaningful walks, the Kolmogorov-Smirnov test was used for walking intensity distribution analysis, and Fisher's exact test was used for maternal and infant outcomes analyses. Pearson correlation was used to examine the association between prepregnancy body mass index and gestational weight gain (GWG). There was significantly more MPA among women in the intervention group compared with those in the control group at V2 (overweight, P < 0.0001; obese, P < 0.025), V3 (overweight, P < 0.0001), and V4 (overweight, P < 0.0001; obese, P < 0.025). Women in the intervention group significantly increased their meaningful walks at V2 (P = 0.054), V3 (P = 0.01), and V4 (P = 0.014). There were trends for intervention group women to have more favorable maternal and birth outcomes compared with the control group. Rates of GWG at measurement points during pregnancy were significantly associated with preceding rates of GWG. The pilot, unsupervised walking intervention increased the MPA of overweight and obese women during pregnancy.

Daily stride rate activity and heart rate response in children with cerebral palsy

To compare daily stride rate activity, daily exercise intensity, and heart rate intensity of stride rate in children with cerebral palsy with that of typically developing children. Forty-three children with cerebral palsy, walking without (Gross Motor Function Classification System (GMFCS) I and II) or with (GMFCS III) an aid and 27 typically developing children (age range 7-14 years) wore a StepWatch™ activity monitor and a heart rate monitor. Time spent and mean heart rate reserve at each stride rate activity level and time spent in each mean heart rate reserve zone was compared. Daily stride rate activity was lower in children with cerebral palsy (39%, 49% and 79% in GMFCS I, II and III, respectively) compared with typically developing children (p < 0.05), while there were no differences in time spent at different mean heart rate reserve zones. Mean heart rate reserve at all stride rate activity levels was not different between typically developing children, GMFCS I and II, while mean heart rate reserve was higher for GFMCS III at stride rates < 30 strides/min (p < 0.05). Stride rate activity levels reflect the effort of walking, in children with cerebral palsy who are walking without aids, similar to that of typically developing, whereas children with cerebral palsy using walking aids show higher effort of walking. Despite a lower stride rate activity in cerebral palsy, daily exercise intensity seems comparable, indicating that the StepWatch™ monitor and the heart rate monitor measure different aspects of physical activity.

AB0487 Etanercept increases step activity in patients with active rheumatoid arthritis and short disease duration

BackgroundThere is strong evidence that TNF-alpha inhibitors improve disability and activities of daily living in patients with active rheumatoid arthritis (RA). However, the supporting data have been generated mainly by...

Plantar pressure and daily cumulative stress in persons affected by leprosy with current, previous and no previous foot ulceration

Not only plantar pressure but also weight-bearing activity affects accumulated mechanical stress to the foot and may be related to foot ulceration. To date, activity has not been accounted for in leprosy. The purpose was to compare barefoot pressure, in-shoe pressure and daily cumulative stress between persons affected by leprosy with and without previous or current foot ulceration.Nine persons with current plantar ulceration were compared to 15 with previous and 15 without previous ulceration. Barefoot peak pressure (EMED-X), in-shoe peak pressure (Pedar-X) and daily cumulative stress (in-shoe forefoot pressure time integral×mean daily strides (Stepwatch™ Activity Monitor)) were measured.Barefoot peak pressure was increased in persons with current and previous compared to no previous foot ulceration (mean±SD=888±222 and 763±335 vs 465±262kPa, p<0.05). In-shoe peak pressure was only increased in persons with current compared to without previous ulceration (mean±SD=412±145 vs 269±70kPa, p<0.05). Daily cumulative stress was not different between groups, although persons with current and previous foot ulceration were less active.Although barefoot peak pressure was increased in people with current and previous plantar ulceration, it did not discriminate between these groups. While in-shoe peak pressure was increased in persons with current ulceration, they were less active, resulting in no difference in daily cumulative stress. Increased in-shoe peak pressure suggests insufficient pressure reducing footwear in persons with current ulceration, highlighting the importance of pressure reducing qualities of footwear.

Accuracy and responsiveness of the stepwatch activity monitor and ActivPAL in patients with COPD when walking with and without a rollator

Purpose: To evaluate the measurement properties of the StepWatch™ Activity Monitor (SAM) and ActivPAL in COPD. Method: Whilst wearing both monitors, participants performed walking tasks at two self-selected speeds, with and without a rollator. Steps obtained using the monitors were compared with that measured by direct observation. Results: Twenty participants aged 73 ± 9 years (FEV1 = 35 ± 13% pred; 8 males) completed the study. Average speeds for the slow and normal walking tasks were 34 ± 7 m·min−1and 46 ± 10 m·min−1, respectively. Agreement between steps recorded by the SAM with steps counted was similar irrespective of speed or rollator use (p = 0.63) with a mean difference and limit of agreement (LOA) of 2 steps·min−1 and 6 steps·min−1, respectively. Agreement for the ActivPAL was worse at slow speeds (mean difference 7 steps·min−1; LOA 10 steps·min−1) compared with normal speeds (mean difference 4 steps·min−1; LOA 5 steps·min−1) (p = 0.03), but was unaffected by rollator use. The change in step rate between slow and normal walking via direct observation was 12 ± 7 steps·min−1 which was similar to that detected by the SAM (12 ± 6 steps·min−1) and ActivPAL (14 ± 7 steps·min−1). Conclusions: The SAM can be used to detect steps in people who walk very slowly including those who use a rollator. Both devices were sensitive to small changes.Implications for RehabilitationThe evaluation of physical activity (PA) before and after pulmonary rehabilitation in people with chronic obstructive pulmonary disease (COPD) has evolved to be an important outcome measure.Selecting an appropriate device to obtain valid measures of PA remains a challenge, especially for those individuals who walk slowly or use a rollator to assist with ambulation.The StepWatchTM Activity Monitor and the ActivPAL have been shown in this study to be sensitive to small changes in step rate, thus these devices can be used to assess changes in physical activity in individuals with COPD such as following pulmonary rehabilitation, including those who walk slowly or use a walking aid such as a rollator.

Are diurnal changes in foot sole sensation dependent on gait activity?

The foot sole is loaded during stance and gait and plantar cutaneous mechanoreceptors sense the local stress distribution. It is not clear whether the perception thresholds of these mechanoreceptors change during the day and how they respond to walking activities. The primary aim of the present study was to investigate diurnal changes of plantar sensitivity. Furthermore, the aim was to find out whether daily changes depend on the individual level of step activity. Twenty-six healthy subjects, 17 women and 9 men, aged 28.6 ± 6.7 years participated in the study. Detection thresholds to light touch were measured in six plantar regions with Semmes–Weinstein monofilaments in the morning, noon and afternoon. Step activity was recorded with a StepWatch™ Activity Monitor and analyzed for three periods (8 a.m.–4 p.m., 8 a.m.–12 p.m., 12 p.m.–4 p.m.). The hallux, the 3rd metatarsal head and the heel showed significantly decreased detection thresholds from 8 a.m. to 4 p.m. ( p ≤ 0.05). A fair correlation between the decrease of detection threshold and the total number of steps was found for the 3rd metatarsal head and the heel ( p ≤ 0.05). Foot sole sensation appears to improve during the day and seems to be associated with the step activity. This may reflect an improving transfer of afferent information to the central nervous system during the day as well as an adaptation of receptors to gait activity.

Walking ability during daily life in patients with osteoarthritis of the knee or the hip and lumbar spinal stenosis: a cross sectional study

BackgroundDegenerative musculoskeletal disorders are among the most frequent diseases occurring in adulthood, often impairing patients' functional mobility and physical activity. The aim of the present study was to investigate and compare the impact of three frequent degenerative musculoskeletal disorders -- knee osteoarthritis (knee OA), hip osteoarthritis (hip OA) and lumbar spinal stenosis (LSS) -- on patients' walking ability.MethodsThe study included 120 participants, with 30 in each patient group and 30 healthy control individuals. A uniaxial accelerometer, the StepWatch™ Activity Monitor (Orthocare Innovations, Seattle, Washington, USA), was used to determine the volume (number of gait cycles per day) and intensity (gait cycles per minute) of walking ability. Non-parametric testing was used for all statistical analyses.ResultsBoth the volume and the intensity of walking ability were significantly lower among the patients in comparison with the healthy control individuals (p < 0.001). Patients with LSS spent 0.4 (IQR 2.8) min/day doing moderately intense walking (>50 gait cycles/min), which was significantly lower in comparison with patients with knee and hip OA at 2.5 (IQR 4.4) and 3.4 (IQR 16.1) min/day, respectively (p < 0.001). No correlations between demographic or anthropometric data and walking ability were found. No technical problems or measuring errors occurred with any of the measurements.ConclusionsPatients with degenerative musculoskeletal disorders suffer limitations in their walking ability. Objective assessment of walking ability appeared to be an easy and feasible tool for measuring such limitations as it provides baseline data and objective information that are more precise than the patients' own subjective estimates. In everyday practice, objective activity assessment can provide feedback for clinicians regarding patients' performance during everyday life and the extent to which this confirms the results of clinical investigations. The method can also be used as a way of encouraging patients to develop a more active lifestyle.

Single-Case Study: Traditional Thermoplastic AFO Versus Adjustable Dynamic Response™—A Crossover Single-Case Study

Past studies have suggested that ankle-foot orthoses (AFOs) improve walking; however, it is unclear what biomechanical designs are most effective. This 10-week trial investigated the effects of a traditional thermoplastic style AFO compared with an Adjustable Dynamic Response™ (ADR™) AFO in a single-case subject. The subject was a 74-year-old man affected by postpolio syndrome with a prior history of AFO use. Patient usage and activity levels were measured with a StepWatch™ Activity Monitor, gait characteristics were measured with a GAITRite® System, and patient satisfaction was measured with a standardized AFO satisfaction questionnaire. The subject wore the traditional AFO for the first 5 weeks of the trial and the ADR™ AFO for the remaining 5 weeks of the trial. Weeks 1 and 5 were considered washout periods, and data were not collected for these weeks with the StepWatch Activity Monitor. Patient usage and activity levels were improved in the ADR™ AFO over the traditional AFO showing an average of 6,606 steps per day in the ADR™ AFO compared with 4,504 steps per day in the traditional AFO. The subject also spent more time engaged in moderate to high activity levels, versus low activity levels, in the ADR™ AFO compared with the traditional AFO. Gait characteristics, such as increased velocity and increased step length, were improved in both AFOs compared with no AFO at all with slightly higher improvements in the ADR™ AFO over the traditional AFO. The AFO satisfaction questionnaire suggested a higher level of patient satisfaction in the ADR™ AFO over the traditional AFO.