EMG power spectrum analysis of first dorsal interosseous muscle in pianists

Purpose: Long-term piano training may induce potential biochemical and stru ctural adaptations in hand intrinsic muscles or alter the motor strategy in the nervous systems. Methods: This study investigated, by electromyography (EMG) and strain gauge, whether this pedagogical training is aerobic or an aerobic by nature. Changes in EMG power spectrum during incremental isometr ic muscle contractions before and after a sustained, fatiguing muscular per formance were studied in the first dorsal interosseous muscle (FDI) of 13 f emale pianists and 15 sedentary controls. The maximal voluntary contraction (MVC) force of the FDI and the time needed to induce fatigue were also mea sured. Results: During fatigue, the median frequency (MF) shifted toward th e low frequencies in both groups. The MF of 50% and 25%MVC subsequent to fa tigue were significantly lower than those before fatigue in the control gro up (104.0 +/- 45.5 Hz vs 116.7 +/- 41.4 Hz at 50%, P < 0.05; 114.7 +/- 43.4 Hz vs 123.3 +/- 46.7 Hz at 25%, P < 0.05). There were no significant,MF ch anges within the pianists before and after fatigue. The root mean squares ( RMS) of 50%, 25%, and 10%MVC of control subjects after fatigue were signifi cantly higher than those before fatigue, but not in pianists. There was no difference in MF and RMS between the two groups at any level of %MVC before or after fatigue, but the pianists tended to show higher MF at each level of %MVC. Although the MVC was similar in both groups, the pianists, however , needed a much longer time to induce fatigue than controls (14.3 +/- 5.8 m in vs 5.8 +/- 3.3 min, P < 0.005). Conclusions: These observations are disc ussed in terms of the training-induced metabolic adaptations, the changes i n the strategy of motor unit recruitment, and the possibility of difference s in muscle fiber composition. This study indicates that piano training sho uld not be classified as power training, rather as endurance training. Such findings may also provide information about fine motor training for athlet es and other professionals.