Regional differences in mitochondrial capacity in the finger flexors of piano players

Abstract

Background: Near-infrared spectroscopy (NIRS) has been used to measure oxidative capacity, but regional differences have not been identified. Piano players are also a novel group of subjects for this lab. Methods: Controls (n = 13) and piano players (n = 8) were tested in a seated position on the right forearm. A fatigue test was performed for three minutes at 2, 4 and 6 Hz using electrical stimulation, which created an endurance index (EI) as the forearm fatigued. A six-cuff oxidative capacity test was performed using manual exercise to activate the muscle and allow for regional specificity. A rate constant (Rc) was generated from the mitochondrial capacity data. Results: Overall, piano players (Rc = 1.76 ± 0.6) and controls (Rc = 1.17 ± 0.3) have significant differences for the last two fingers (p = 0.01). While controls have significant differences between the index (Rc = 1.86 ± 0.5) and last two fingers (Rc = 1.17 ± 0.3) (p = 0.001), this difference was not observed in piano players. Overall, piano players (EI = 75.7 ± 12.3) and controls (EI = 73.0 ± 17.3) had no differences in endurance index values (p = 0.71). Conclusions: Piano players have significant differences in the mitochondrial capacity of the finger flexors that control the last two fingers compared to controls. The lack of difference between groups in the index fingers and overall endurance test suggests playing the piano produces training adaptations to the finger flexor muscles of the last two digits, which are rarely used by control subjects.