Time history of upper-limb muscle activity during isolated piano keystrokes.

Playing-related musculoskeletal disorders (PRMDs) in pianists can lead to the cessation of performance-related activities. A better understanding of the impact of performance parameters on muscle activities could help improve prevention of pianists' PRMDs. The purpose of this study was to assess the effect of touch and articulation (two performance parameters) on muscle activity and to compare analysis based on scalar and time-history values. Activity of nine upper-limb muscles were recorded in 12 professional classical pianists during the performance of slow-paced isolated keystrokes using pressed and struck touch and staccato and tenuto articulation. A two-way (touch and articulation) ANOVA with repeated measures was performed on time history and single-point values of muscle activations. Pressed touch prime mover muscle was the triceps brachii while struck touch entailed progressive deactivation of anti-gravity muscles before the keystroke. Compared to tenuto articulation, staccato articulation induced a muscular burst on shoulder muscles. Our results suggest that warm-up routines aiming to prevent PRMDs should integrate different types of touch and articulation. Staccato articulation appears however to be an important risk factor of PRMDs located at the shoulder structure. Temporal analysis was a more reliable tool to interpret pianists' muscle activity during keystrokes.