Assessment of the presence of independent flexor digitorum superficialis function in the small fingers of professional string players: is this an example of natural selection?

This study estimated the prevalence of independent flexor digitorum superficialis function in the small fingers of 90 violin and viola players. The hypothesis tested was that the independent digital movements required in this population would select out those with absent flexor digitorum superficialis function. Professional string players were tested clinically, using standard and modified tests, for flexor digitorum superficialis function. Two additional physical tests were applied: the gap and stretch tests. These tests assess ring finger movement once the small finger is placed and the instrument is held in the chin-hold position. A statistically significant reduction in the prevalence of absent flexor digitorum superficialis function was confirmed in the musicians compared with a control group and published meta-analysis. This suggests that independent flexor digitorum superficialis function is important for professional musicians playing at an elite level.