Effect of occupational keyboard typing on magnetic resonance imaging of the median nerve in subjects with and without symptoms of carpal tunnel syndrome.

Objective: To examine the effects of occupational keyboard typing on median nerve shape and T2 relaxation and on forearm muscle T2 in professional typists with and without symptoms of carpal tunnel syndrome.

Design: Based on the Levine Carpal Tunnel Syndrome Symptom Severity scale (LCTSS), 12 female professional typist volunteers were divided into asymptomatic (LCTSS < 1.3, n = 5) and symptomatic (LCTSS > 1.