Article

The ability to perform a sit-to-stand (STS) motion is important for ambulatory
adults to function independently and maintain daily activities. Roughly 6% of
community-dwelling older adults experience significant difficulties with STS, a
major risk factor for institutionalization. While mechanical STS assistance can
help address this problem, full dependence on STS assistance provided by devices
such as lift chairs can lead to atrophy of the leg muscles. We investigated the
mechanics of assisted STS motion in order to better understand how load-sharing
STS mechanisms may facilitate STS motions while still requiring activation of the
leg muscles. Experiments were conducted with 17 nondisabled older adults
performing unassisted and assisted STS rises with grab bar, arm, seat, and waist
assistance. Each mode of rise was evaluated based on a subject questionnaire and
key biomechanical metrics relating to stability, knee effort reduction, and rise
trajectory. Results show that the seat- and waist-assist modes provide
statistically significant improvements in stability metrics and reductions in
required knee torques over unassisted rises and bar assistance. The assists most
preferred by the subjects were the seat and bar assists. Overall, our results
favor a seat-assisted STS modality for nonclinical applications and indicate
further testing of this modality with a clinical population.

Langue : ANGLAIS