Age-dependent changes in position sense in human proximal interphalangeal joints.

USING a position matching paradigm, the ability of subjects to detect displacements at the proximal interphalangeal joint of the index finger was tested. These displacements were imposed at an angular velocity of 2 degrees per minute which is below the threshold for movement detection. An older group of subjects whose mean age (± s.e.m.) was 56.6 ± 3.2 years showed significantly poorer performance in detecting the position of the index finger than a group of younger subjects (23.7 ± 0.5 years). Analysis of the correlation between age and magnitude of matching error gave a positive correlation coefficient of 0.466 which was statistically significant. However, there was no systematic bias in judgements of finger position by the older group. These results indicate that the sense of position of the fingers decrements with age.