Objective evaluation of fine motor manipulation-a new clinical tool

A new performance-based tool has been developed to accurately and precisely evaluate finger/hand function during manipulation of any object, independent of geometric and surface properties. The objectives of this study were to show test-retest reliability and evaluate criterion validity. Twenty healthy, right-handed participants were recruited. Three objects ranging in weight and size, requiring two or three fingers, were instrumented with a motion sensor that tracked 3D linear/angular motion. A computerized visual-guided tracking task was used to quantify motor performance during object manipulation. Two testing periods, one week apart were performed to evaluate test-retest reliability. Criterion validity was assessed by comparing performance with this tool to performance on commonly used clinical dexterity tests. Global performance, temporal accuracy, and amplitude consistency during manipulation of the objects compared with the reference waveform were highly reliable on the two testing occasions. Low-moderate correlations between the clinical dexterity tests and the task protocol indicate that different aspects of hand function were measured. The task protocol directly measures the ability of the hand to coordinate movement in response to a visual tracking target. Providing effective and objective ways to evaluate manual dexterity and hand function is a critical part of evidence-based practice.