Descriptive data of subjects included in the study.

<p>Values are mean ± SD. CSA; cross-sectional area. There were no significant differences between patient and control groups in either dominant or non-dominant arms.</p>*<p>Significant differences: dominant vs. non-dominant arm, paired data Student-t test, p<0.001. Instrumentalists by instrument (controls/patients): Piano (3/5), Guitar (2/0), Electric guitar (1/2), Saxophone (1/1), Clarinet (1/1), Double bass (0/1), Drums (0/1).</p

Representative time courses of metabolite raw amplitudes, intracellular pHs, and total Pi/PCr ratios during exercise.

<p>A, MRS pattern A; B, MRS pattern B; PCr, phosphocreatine; Pi, inorganic phosphate (N-Pi, neutral-pH peak; L-Pi, low-pH peak). Data were obtained from 64 s spectra and the displayed symbol times are the centre point of the time periods.</p

Representative ³¹P spectra of the finger extensor muscles at rest and during exercise.

<p>A, MRS pattern A (control); B, MRS pattern B (patient). Peak assignments: ATP, adenosine triphosphate; PCr, phosphocreatine; Pi, inorganic phosphate (N-Pi, neutral-pH peak; L-Pi, low-pH peak). The spectra are the sum of 32 scans (64 s) The displayed spectra times are the centre points of such time periods. Note the appearance of a second and acidic Pi peak (L-Pi) in pattern B spectra. Exercise in the chosen example of pattern A was performed for a longer time period without Pi splitting, but only the same time points as in pattern B example are shown for comparison purposes.</p