Body sway and vibration perception thresholds in normal aging and in patients with polyneuropathy.

Abstract

Body sway and vibration perception in the lower limbs were measured in 32 normal subjects and 25 patients with peripheral neuropathies; nerve conduction studies were also performed in the patients with neuropathies. Body sway was measured by means of force-plate posturography, and three methods were used to assess vibration perception: a neurothesiometer, a semiquantitative tuning fork, and the bone vibrator of a conventional audiometer. Body sway and vibration perception were increased in the patients with peripheral neuropathies, and there was significant correlation between these measures. These findings, together with the lack of correlation between sway and muscle strength, indicate that the main source of unsteadiness in these patients is the loss of proprioceptive information. Vibration perception and body sway did not correlate with the electrophysiological variables, indicating that these measures assess different aspects of peripheral nerve function. In all subjects there was close correlation between vibration perception as assessed by the neurothesiometer and the audiometer, indicating that the audiometer could be used to screen proprioceptive fimction in patients with balance disorders. In normal subjects age correlated with vibration perception (measured with the neurothesiometer and audiometer) and also with body sway standing on foam. This suggests that the increased body sway in elderly people may partly be due to reduced proprioception in the lower limbs. (y Neurol Neurosurg Psychiatry 1995;58:335-340)

Contributions of altered sensation and feedback responses to changes in coordination of postural control due to aging

“…In fact, our results indicate that the mean ankle control gains were generally (if not always significantly) higher for the elderly than the young subjects, suggesting that the older subjects were able to generate sufficient ankle torque in our test of quiet standing. This agrees with Bergin et al [29] who suggested that a lack of proprioception, rather than weakness, cause older subjects to be unsteady. Additionally, Hughes et al [30] found that subject with impaired ankle range of motion did not perform differently on measures of postural sway than those with unimpaired ankle dorsiflexion.…”

“…In fact, overall feedback gain changed significantly only for condition 3, but not for condition 6. We propose that the increased sway of elderly subjects in the platform sway-referenced conditions is due to sensor noise or decreased ability to detect small motions of the platform, while the increased sway during visual sway-referencing is due to re-weighting of the various sensors. It has been suggested that proprioceptive input is the most important for maintenance of balance and that visual input cannot fully compensate for an impairment in proprioception [2,29]. The difference between young and elderly subjects in response to both platform and visual sway-referencing on SOT condition 6 is due to both an increase in the amount of sway and a change in the coordination of sway.…”

Independent effects of peripheral nerve dysfunction on lower-extremity physical function in old age: the Women's Health and Aging Study.

“…That 90% of women with severe PND could not complete the tandem stand suggests that this simple test may be specific for identifying individuals with the most severe deficits. Our findings are consistent with previous studies demonstrating associations between PND measured by VPT and impaired proprioception (24,25,29). A key question that cannot be answered here is whether further adjustment for PNDassociated impairments would have abolished the residual association between PND and functional limitations.…”

The Effects of Knee and Ankle Muscles Surrounding the Knee and Ankle Joints on One-Leg Static Standing Balance

“…Human balance is maintained through a complex process involving sensory detection of body motion, integration of sensorimotor information within the central nervous system, and the execution of appropriate musculoskeletal responses 6) . Factors influencing balance such as age 7,8) , muscle weakness 9) , vibration sense 10) , respiration 11) , and visual input 12) have been studied. However there have been no studies on the effect of muscular fatigue on balance yet.…”