Abstract
Postural control mechanism and risk factors for accidental falls were studied in elderly persons. Posturography measurement was performed with vibration to stimulate calf muscles at different frequencies from 20, 40, 60, 80, to 100 Hz arranged in a pseudo-random fashions.
Sway velocity was measured to reflect postural control under visual and non-visual conditions with and without vibration. Under non-visual conditions, sway velocity was increased in elderly persons. In elderly persons, postural stability was controlled much more by visual input than by referents due to deterioration of vestibular and proprioceptive control of posture. Romberg's quotient in elderly who fell frequently (fallers) differed significantly from that of those who did not fall frequently (non-fallers) (P<0.01).
Fallers did not use visual input to control their posture. Proprioception from calf muscles was poorer in fallers than in the non-fallers.
In risk factor analysis, lateral body sway, Romberg's quotient, poor vision, support, motility, parkinsonism and muscle hypotony were predictive for accidental falls.To prevent falls, rehabilitation programs should be attempted to enhance proprioreceptor or pressoreceptor cues. Visual input should be promoted by sufficient visual illumination and contrasting visual surroundings.
