The effect of altered hand position and motor skills on stereognosis.

Overview

PURPOSE: Poor stereognosis has been considered to be indicative of abnormal cerebral sensory function, and therefore a relative contraindication for upper extremity surgery in hemiplegic cerebral palsy. The effect of hand position and motor function on stereognosis has not been studied; decreased hand mobility can decrease a person's ability to recognize objects in the hand and can be an important component of stereognosis. METHODS: Twenty-one normal subjects had their nondominant arm positioned to simulate the hemiplegic hand posture of forearm pronation and wrist and digital flexion. Subjects were asked to identify 12 common objects in 3 successive trials, with the first and third trials in the simulated hemiplegic position and the second trial in normal hand position and motor function. This accounted for a learning effect. RESULTS: Normal subjects had significantly (p < .0001) decreased stereognosis when placed in a simulated hemiplegic hand position with decreased digital and wrist extension, identifying fewer items (means 7.6 and 9.3 in successive trials) in the hemiplegic hand position than in the normal hand position (mean 11.7). CONCLUSIONS: Decreased stereognosis in cerebral palsy patients might be related to altered hand mobility and not solely to central nervous system dysfunction. It should be used cautiously when guiding surgical indication, as it may be surgically correctable.