Investigating joint kinematics during a hoist-assisted sit-to-stand activity

Abstract

Assisting individuals to stand up from a chair, or sit-to-stand (STS), is a physically demanding task restricted by manual handling regulations. If a hoist was able to produce a normal STS movement pattern this would offer a safe option for both therapist and patient, satisfying both therapeutic and manual handling criteria. Twenty-two healthy subjects participated in the study. Each subject completed STS with and without hoist assistance. Two hoists were used: the Sara 3000 and the Encore. The STS movements were captured on digital camera and the knee and trunk angles were calculated at point of seat-off for unassisted STS, Sara 3000 STS and Encore STS. Data were analysed using a repeated measures ANOVA. Trunk angles during STS using both hoists were found to be different (P < 0.001) from that seen during normal STS. Knee angles measured when using the Sara 3000 hoist were different to those seen during unassisted (or normal) STS; however, knee angles at seat-off for the Encore hoist were similar to those seen during normal STS. This study analysed the movement patterns re-created by two hoists used in the clinical setting. Results showed that the Encore hoist is effective at re-creating normal knee angles at seat-off during the STS transfer, however, neither hoist is able to encourage the required normal trunk angle for independent STS.