Coin rotation task (CRT): a new test of motor dexterity.

Coin-rotation task (CRT), a measure of rapid, coordinated finger movements, was devised as a convenient, easily administered bedside test of motor dexterity; however, very little psychometric data exist regarding this task. The current project was undertaken to (a) provide preliminary normative data, (b) examine the convergent and discriminant validity of the task when compared with other standardized motor measures, and (c) examine the diagnostic accuracy of the CRT. The sample of 86 male participants included 60 controls and 26 patients with unilateral lesions of the left (n = 13) and right (n = 13) hemispheres. The CRT was not significantly correlated with age or education; non-adjusted left- and right-hand normative data are provided. The CRT demonstrated good convergent and divergent validity when compared with other standardized motor measures. The CRT was successful in differentiating control and brain damaged groups with mild motor impairment, and demonstrated an overall classification rate of 84.9%. Levels of sensitivity and specificity of the CRT were comparable with or better than other standardized tests of manual dexterity. The CRT offers a valid, quick, and convenient bedside measure of subtle motor impairment.