Finger-movement tracking scores in healthy subjects.

The purpose of this study was to examine the effects of age, sex, and hand preference on precise control of voluntary movement at the index finger metacarpophalangeal joint in able-bodied volunteers. An electrogoniometer was attached to this joint and connected to a computer. The computer screen displayed a sine wave target that each subject attempted to track with careful extension and flexion finger movements. Accuracy index scores were calculated for the extension phases, flexion phases, and the total sine wave. Each subject performed three tracking trials and the average for each of the above scores was computed. The results showed that younger subjects tracked significantly more accurately than older subjects and men tracked significantly more accurately than women. Also, the subjects tracking with the nonpreferred hand (15 right, 105 left) tracked significantly more accurately than those subjects tracking with the preferred hand (112 right, 8 left) in the flexion phases of the test. The data from these able-bodied subjects provide a base for comparison of patients' data, which may be helpful in the early recognition and monitoring of problems with precision in movement control.