Postural Control in Elderly Subjects

TLDR

Postural control declines in the elderly due to loss of pressoreceptor cues and impaired muscle spindle reflexes. The study assessed postural stability in 23 octogenarians using a force platform while perturbing lower‑limb sensory input with calf‑muscle vibration and foam‑covered platforms. Elderly participants exhibited higher sway velocities than younger controls, and perturbing muscle spindles or pressoreceptors did not worsen instability, but visual deprivation reduced stability by about 50%, indicating a heavy reliance on vision that may increase fall risk.

Abstract

The postural stability of 23 subjects aged 85 years or over was studied with a force platform. The sensory function of the lower limbs was disturbed with small vibrators placed on both calf muscles and/or by placing the subjects on a platform covered with foam plastic. When compared with a group (n= 100) of 50–60-year-old subjects, the elderly subjects had significantly higher sway velocities even during non-perturbed conditions. The perturbation of muscle spindles with vibration and/or pressoreceptor function with foam plastic did not increase the postural instability of the elderly subjects. Visual deprivation had a significant effect on postural stability, and the visual influx contributed about 50% of the postural stability. Postural control is reduced as a result of loss of sensory cues of pressoreceptors and also deterioration in function of stretch reflexes initiated from muscle spindles. The very elderly seem to rely on visual control of posture; this is slow, which can be one reason for susceptibility to falls.