Quantifying thumb rotation during circumduction utilizing a video technique.

Abstract

Thumb rotation is an essential component of circumduction in order to achieve pulp to pulp contact. In order to evaluate opponensplasty, a device was developed to quantify thumb rotation utilizing a special jig to hold the hand and video analysis. Twenty-seven healthy volunteers (12 female and 15 male) were tested to obtain normative data. Thumb rotation was measured as the difference in angle between the thumb in abduction and extension and maximal circumduction. Rotation angles varied from 70 degrees to 110 degrees. No gender or right/left differences could be detected. We concluded that comparing rotation of the non-injured hand to the injured hand in evaluating opponensplasties can be used as an accurate measurement of thumb circumduction and opposition.