The Accuracy of the Detection of Body Postures and Movements Using a Physical Activity Monitor in People after a Stroke

Background: In stroke rehabilitation not only are the levels of physical activity important, but body postures and movements performed during one’s daily-life are also important. This information is provided by a new one-sensor accelerometer that is commercially available, low-cost, and user-friendly. The present study examines the accuracy of this activity monitor (Activ8) in detecting several classes of body postures and movements in people after a stroke. Methods: Twenty-five people after a stroke participated in an activity protocol with either basic activities or daily-life activities performed in a laboratory and/or at home. Participants wore an Activ8 on their less-affected thigh. The primary outcome was the difference in registered time for the merged class “upright position” (standing/walking/running) between the Activ8 and the video recording (the reference method). Secondary analyses focused on classes other than “upright position”. Results: The Activ8 underestimated the merged class “upright position” by 3.8% (775 s). The secondary analyses showed an overestimation of “lying/sitting” (4.5% (569 s)) and of “cycling” (6.5% (206 s)). The differences were lowest for basic activities in the laboratory and highest for daily-life activities at home. Conclusions: The Activ8 is sufficiently accurate in detecting different classes of body postures and movements of people after a stroke during basic activities and daily-life activities in a laboratory and/or at home

A Novel Tool for Quantifying and Promoting Physical Activity in Youths With Typical Development and Youths Who Are Ambulatory and Have Motor Disability

Background. Several device-based instruments have been validated in the pediatric population, but none of these are clinically applicable and provide real-time feedback on actual physical activity in terms of postures and movements. A new device (Activ8) is promising for that purpose.Objective. The objective was to investigate the criterion validity of the Activ8 for measuring static (sitting, standing) and dynamic (walking, bicycling, running) activities, and for separating postures and movements within basic and complex activities in children and adolescents (youths) with typical development (TD) and peers with motor disability (not typical development [NTD]).Design. This was a criterion validation study.Methods. Ten participants with TD (mean age [standard deviation] = 14 [2.5] years) and 10 participants with NTD (mean age = 12.9 [2.1] years) performed a standardized series of basic and daily life (complex) activities. The Activ8 measured postures and movements, while camera recording served as a reference. The outcome measures were the mean time differences between the Activ8 output and video data for the merged categories "static" and "dynamic" and for the separate postures and movements.Results. For the merged categories static and dynamic, the criterion validity was found to be excellent both in participants with TD and participants with NTD within basic activities, and was found to be good to excellent in participants with TD and moderate to good in participants with NTD within complex activities. The detection of separate postures and movements was found to be poor to excellent in both groups within complex activities.Limitations. The sample of youths with NTD was small and limited to youths who could be considered to be at least ambulatory within a household.Conclusions. Activ8 is a valid tool when the merged categories static and dynamic are used to interpret physical activity in daily life in both youths with TD and youths with NTD and mild motor impairment. To optimize the quantification of separate postures and movements, adjustment of the existing algorithm is required

Does Activity-Based Rehabilitation With Goal Attainment Scaling Increase Physical Activity Among Younger Knee Arthroplasty Patients? Results From the Randomized Controlled ACTION Trial

Background: Especially in younger knee osteoarthritis patients, the ability to perform physical activity (PA) after knee arthroplasty (KA) is of paramount importance, given many patients’ wish to return to work and perform demanding leisure time activities. Goal Attainment Scaling (GAS) rehabilitation after KA may improve PA because it uses individualized activity goals. Therefore, our aim was to objectively quantify PA changes after KA and to compare GAS-based rehabilitation to standard rehabilitation. Methods: Data were obtained from the randomized controlled ACTION trial, which compares standard rehabilitation with GAS-based rehabilitation after total and unicompartmental KA in patients <65 years of age. At 2 time points, preoperatively and 6 months postoperatively, 120 KA patients wore a validated 3-dimensional accelerometer for 1 consecutive week. Data were classified as sedentary (lying, sitting), standing, and active (walking, cycling, running). Repeated measures analysis of variance was used to compare PA changes over time. Results: Complete data were obtained for 97 patients (58% female), with a mean age of 58 years (±4.8). For the total group, we observed a significant increase in PA of 9 minutes (±37) per day (P = .01) and significant decrease in sedentary time of 20 minutes (±79) per day (P = .02). There was no difference in standing time (P = .11). There was no difference between the control group and the intervention group regarding changes in PA, nor between the total KA group and the unicompartmental KA group. Conclusion: We found a small but significant increase in overall PA after KA, but no difference between GAS-based rehabilitation and standard rehabilitation. Likely, enhanced multidisciplinary perioperative strategies are needed to further improve PA after KA

Detection of body postures and movements in ambulatory adults with cerebral palsy: a novel and valid measure of physical behaviour

Background: Accurate measurement of physical behaviour is paramount to better understand lifestyle, health, and functioning, particularly in adults with physical disability as they may be at higher risk of sedentary lifestyle and subsequent negative health consequences. This study aimed: 1) to evaluate the criterion validity of a novel and clinically applicable activity monitor (AM, Activ8), in the detection of body postures and movements in adults with spastic cerebral palsy (CP); and 2) to evaluate the extent that the AM's positioning affects validity.Methods: In this cross-sectional study, 14 ambulatory adults with CP [9 men; mean (SD) age, 35.4 (13.1) years] performed standardized activities while wearing three Activ8 monitors - frontolateral thigh (primary position), frontal thigh, and pant pocket - and being video recorded (criterion measure). AM activity output was compared to synchronized video recordings. Absolute (seconds) and relative [(video time-AM time)/mean time, %] time differences between methods were calculated. Relative time differences of < 10% were indicative of good validity. Comparison of AM attachment positions was completed using Spearman Rho correlation coefficients and Meng's tests.Results: Criterion validity of the AM (frontolateral thigh) was good (average relative time differences: 0.25% for sitting, 4.69% for standing, 2.46% for walking, 1.96% for upright activity, 3.19% for cycling), except for running (34.6%). Spearman Rho correlation coefficients were greater between video/frontolateral thigh position than video/frontal thigh position and video/pant pocket position for body posture and movement categories sitting, standing, walking, and upright activity (p < 0.01 for all).Conclusions: The AM, positioned on the frontolateral thigh, demonstrated good criterion validity in ambulatory adults with CP. Though the Activ8 offers potential as an objective measure of physical activity, appropriate positioning is paramount for valid measurement