Association Between Free-Living Sit-to-Stand Transition Characteristics, and Lower-Extremity Performance, Fear of Falling, and Stair Negotiation Difficulties Among Community-Dwelling 75 to 85-Year-Old Adults

Abstract

Background Good sit-to-stand (STS) performance is an important factor in maintaining functional independence. This study investigated whether free-living STS transition volume and intensity, assessed by a thigh-worn accelerometer, is associated with characteristics related to functional independence. Methods Free-living thigh-worn accelerometry was recorded continuously for 3–7 days in a population-based sample of 75-, 80-, and 85-year-old community-dwelling people (479 participants; women n = 287, men n = 192). The records were used to evaluate the number and intensity (angular velocity of the STS phase) of STS transitions. Associations with short physical performance battery (SPPB), 5-times-sit-to-stand test (5×STS), isometric knee extension force, self-reported fear of falls, and self-reported difficulty in negotiating stairs were also assessed. Results The number of STS transitions, mean and maximal angular velocity were lower in older age groups (p < .05). All variables were higher in men than in women (p < .001) and were positively associated with SPPB total points, knee extension force (r ranged from 0.18 to 0.39, all p < .001) and negatively associated with 5×STS (r = −0.13 – −0.24, all p < .05), lower extremity functional limitations (p < .01), fear of falls (p < .01), and stair negotiation difficulties (p < .01). Conclusions Free-living STS characteristics were related to lower-extremity performance, lower extremity functional limitations, self-reported fear of falls, and stair negotiation difficulties, which can be a sensitive indicator of impending functional decline. Moreover, STS transitions may provide an indicator of adequacy of lower-limb muscle strength among older individuals.

Association of Sit-to-Stand Capacity and Free-Living Performance Using Thigh-Worn Accelerometers among 60- to 90-Yr-Old Adults

“…Future studies could examine whether STS performance differs between working days and days off. Second, although we have found the accuracy of identifying STS transitions to be greater than 90% and the angular velocity determination to be accurate (14,15), there are always misclassifications of free-living movements. There is no way to know for sure whether a behavior that appears to be an STS transition in the free-living accelerometer data is actually an STS transition and whether an exceptional technique (e.g., arm utilization, seat height, assistance from another person) was used to perform a given STS transition.…”

“…The number of STS was determined as the mean of the transitions (number) per complete monitoring day. No participant exceeded 4 rad·s −1 in the laboratory (highest was 3.89 rad·s −1 ), and therefore we filtered out any STS transitions above 4 rad·s −1 from the data before the estimation of the maximum free-living angular velocity (14). A total of 73 transitions were removed because of this (from 64 participants), and this was 0.036% of all 97,401 transitions detected in this data set.…”

“…Freeliving STS transitions were identified from the accelerometer data using the open access and universal algorithm that we have developed, which detects STS transitions and quantifies the angular velocity of the transition. The structure, source code (26), and properties of the algorithm are described elsewhere (14,15). The quantification accuracy of angular velocity against 2D motion analysis was good, and the detection accuracy of STS transitions was 93.3% (15).…”

“…On average, community-dwelling older adults have been reported to perform 45 STS transitions per day (13,14). The combination of the relatively high capacity demand, and the fact that people engage with the STS multiple times a day makes this movement a potential candidate for free-living strength-demanding activity monitoring.…”

“…The combination of the relatively high capacity demand, and the fact that people engage with the STS multiple times a day makes this movement a potential candidate for free-living strength-demanding activity monitoring. Wearable sensor technology has made it possible to measure and detect STS transitions based on thigh angular velocity in free-living environment (14)(15)(16)(17)(18). The test capacity of STS transitions in the laboratory and clinical settings has commonly been studied using the 5ÂSTS test completion time (19,20).…”