Evaluation of sit-to-stand motion using a pressure distribution measurement system--effect of differences in seat hardness on sit-to-stand motion.

PURPOSE: This study examined differences between standing from an ordinary seat and standing from a low-repulsion mat using a pressure distribution measurement system (BIG-MAT) and identified parameters to determine sit-to-stand (STS) motion difficulty.

METHOD: Ten healthy male volunteers (aged 30-38 years) participated. During STS motion from an ordinary seat and from a low-repulsion urethane mat, plantar surface pressure changes of both feet and the centre of pressure (COP) trajectory were recorded for 7  s. This series of tests was performed four times in each subject. Left and right pressure changes and COP changes were evaluated. Differences in the measurements between the low-repulsion mat and the ordinary seat were compared using the paired t-test.

RESULTS

COP changes were similar to those previously reported. Time from hindfoot peak to forefoot peak was significantly shorter with the ordinary chair than with the mat (p < 0.05). Percent change in forefoot pressure at forefoot peak and hindfoot peak (p < 0.01) and percent change in forefoot pressure at forefoot peak and stabilisation (p < 0.05) were significantly different.

CONCLUSIONS

Time from hindfoot peak to forefoot peak and percent change in forefoot pressure at forefoot peak and hindfoot peak were the best indicators of STS motion difficulty.