Comparison of seat, waist, and arm sit-to-stand assistance modalities in elderly population

Jeswin Jeyasurya, H. F. Machiel Van der Loos, Antony Hodgson, Elizabeth A. Croft

Research output: Contribution to journalArticleResearchpeer-review

18 Citations (Scopus)


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.

Original languageEnglish
Pages (from-to)835-844
Number of pages10
JournalJournal of Rehabilitation Research and Development
Issue number6
Publication statusPublished - 2013
Externally publishedYes


  • Assistive device
  • Assistive robotics
  • Assistive test bed
  • Biomechanics
  • Chair rise
  • Elderly
  • Load sharing
  • Mobility impairment
  • Seat assist
  • Sit-to-stand

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