Impact of seat height and grab bars on postural stability and muscle activity of older females standing from a toilet.

BACKGROUND

Postural stability and muscle activity of older females were assessed during a sit-to-stand (STS) task completed from a standard North American toilet. Four STS toilet setups were examined: normal height (normalheight), raised seat (raisedseat), and normal and raised seats with bilateral grab bars (normalheightbars, raisedseatbars).

METHODS

Eight older (72 ± 6 years) and 8 younger females (21 ± 1 years) participated. Total movement time, STS difficulty measured as the time from hindfoot to forefoot plantar pressure peaks, and center of pressure (COP) displacement were evaluated. Surface electromyography (EMG) captured muscle activity in the vastus medialis (VM), biceps femoris, calf muscles, and tibialis anterior (TA).

RESULTS

Raisedseat, normalheightbars, and raisedseatbars reduced STS difficulty. Raising the seat reduced EMG activity in VM, TA, and calf muscles. Adding bars lowered biceps femoris and calf muscle EMG, and increased VM and TA activity. Normalheightbars and raisedseatbars lowered COP speed (P = .01) and displacement (P = .03) compared to normalheight and raisedseat. Conversely, raisedseat and raisedseatbars increased COP speed and displacement (P < .001) for young and older females.

CONCLUSION

Normalheightbars provides the most stability and reduces STS difficulty, making it the best intervention for improving postural stability in older females standing up from a toilet.