This right-handed, 22-year-old guitarist presents with a 4.5-year history of left arm symptoms, which worsen with prolonged guitar playing. Discomfort is localized at the left antecubital fossa and might spread to the volar wrist and pectoral muscle region. A swelling is sometimes felt
at the proximal forearm, occasionally associated with erythema. Discomfort is sometimes worse in the morning after a long day of guitar playing. In general, he feels that his muscles are weaker than before, as he has not been using them as much, but there is no localized muscle weakness, numbness,
or tingling.