Impact of Long Flexor Versus Intrinsic Dominance in the Generation of Arc of Finger Flexion.

Finger flexion is a composite movement involving both long flexors and intrinsic hand muscles. Previous studies have characterized this but have not investigated differences within the normal population. Were discrete finger motion patterns identified, this could guide rehabilitation programs following flexor tendon surgery. Twelve volunteers repeatedly flexed and extended at a comfortable speed, resting their hand on a horizontal surface. Video was recorded perpendicular to the little finger flexion plane, and the little finger tip position was identified frame by frame to create a composite curve. Its highest point was noted, and the horizontal distance was measured from this point to the palmar digital crease (Δ). In addition, 2 investigators independently reviewed frame-by-frame images and allocated subjects into groups based on the motion pattern. Δ demonstrated 2 clusters within our study population, and there was a statistically significant ( < .036) difference between groups. This study demonstrated that qualitative and quantitative differences exist in flexion curves between individuals.