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

Abstract

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.

Feasibility and short-term effects of Activity Coach+: a physical activity intervention in hard-to-reach people with a physical disability

“…Objective measurement of PA PA during activities of daily living was objectively measured using the Activ8, a tri-axis accelerometer (2M Engineering, Valkenswaard, The Netherlands) [26]. The Activ8 was attached to the ventral side of the thigh (at 10 cm from proximal, in the middle in the frontal plane).…”

“…Time per activity per day was calculated as absolute time (minutes) and as percentage time (absolute time divided by total wear time  100%). Daily PA was expressed as percentage of time spent active, intensity of behaviour (counts/min), average number of active bouts, and mean duration of active bouts [26].…”

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

“…In the output file, a summation of time spent in specific body postures and movements over 5-minute epochs is given. The Activ8 reliably measures and classifies PA into 5 categories: lying/sitting, standing, walking, cycling, and running/high-intensity activity [22]. To obtain valid measurements, a minimum of 3-5 consecutive days of measuring is recommended [23].…”

“…If, for any reason, patients were unable to complete the measurement, we used a minimum of 3 measurement days for inclusion in the analysis. The accelerometer was attached with Tegaderm skin tape to the front of the nonoperated thigh, halfway between the hip and knee [22]. Patients were asked to keep a diary including dates, time in and out of bed, and nonwear, for instance patients were asked to remove the monitor when bathing or swimming.…”

Movement behavior remains stable in stroke survivors within the first two months after returning home

“…The device is able to store data for sixty days, and its battery life is at least 30 days [46]. The Activ8 has been validated in a community-living stroke population in terms of postures and in a healthy population in terms of energy expenditures [47,48].…”