Relative effort changes during sit to stand and stand to sit transition following muscle damage

Abstract

Sit to stand transition (STST) is sometimes considered as the reverse task of the stand to sit transition (StST). The challenges of STST and StST are exemplified by the welfare issue of elderly humans being unable to rise from a chair and sit on a chair due to loss of muscle strength. STST and StST like any activity of daily living loads the musculoskeletal system (load) and muscles have to produce adequate force (capacity) for fulfilling the task safely.
The aim of this study was: a) to investigate the relative effort changes of STST and StST caused by DOMS and b) identifying which task is most demanding before and after muscle damage protocol. Eighteen physically active females participated in this study. Two-way ANOVA (4 times × 2 muscle groups) was used to analyze DOMS, two-way ANOVA (2 times × 2 tasks) was used to analyze the relative effort and two-way ANOVA (5 times × 2 muscle groups) was used to analyze isometric average peak torque. All muscle damage indices altered significantly after the eccentric exercise confirming that muscle damage did occur. In both tasks the relative effort is almost the same although the muscle activation and contraction is different. Those results could be helpful in rehabilitation of individuals with movement difficulties due to aging or other pathology.

Key words:

biomechanics, muscle damage, DOMS, sit to stand