Hand span and digital motion on the keyboard: concerns of overuse syndrome in musicians

Abstract

Purpose: To investigate the hand motion of pianists when they performed an octave and a chord, which accounted for 74% of the piano techniques that the subjects practiced at the onset of overuse hand problems. The octave position was to strike 2 keys that were 16.7 cm apart simultaneously with the thumb and small finger, and the chord position was to strike 3 keys with 4.8 cm between the borders.

Methods: The abduction angle of both the thumbs and the small fingers of 10 pianists while playing a chord and an octave were measured repeatedly with a video-based passive marker detection system. The angles were compared between pianists with large hand spans and those with small hand spans.

Results: When playing the octave both the maximal and minimal abduction angles of the thumb were significantly larger for the smaller-hand pianists as compared with the pianists with larger hand spans. When playing the chord the maximal abduction angle of the thumb of small-hand-span pianists was significantly larger than that of large-hand-span pianists. The abduction of the small finger, however, did not differ during performance of either the octave or the chord.

Conclusions: These results suggest that the small-hand-span pianists must abduct the thumb more than large-hand-span pianists while minimizing movement of the small finger. This may cause de Quervain's tenosynovitis in pianists.