|dc.description.abstract||Objective: Overuse injuries in violinists are a problem that has been primarily
analyzed through the use of questionnaires. Simultaneous 3D motion analysis and EMG
to measure muscle activity has been suggested as a quantitative technique to explore this
problem by identifying movement patterns and muscular demands which may predispose
violinists to overuse injuries. This multi-disciplinary analysis technique has, so far, had
limited use in the music world. The purpose of this study was to use it to characterize the
demands of a violin bowing task.
Subjects: Twelve injury-free violinists volunteered for the study. The subjects
were assigned to a novice or expert group based on playing experience, as determined by
Design and Settings: Muscle activity and movement patterns were assessed while
violinists played five bowing cycles (one bowing cycle = one down-bow + one up-bow)
on each string (G, D, A, E), at a pulse of 4 beats per bow and 100 beats per minute.
Measurements: An upper extremity model created using coordinate data from
markers placed on the right acromion process, lateral epicondyle of the humerus and
ulnar styloid was used to determine minimum and maximum joint angles, ranges of
motion (ROM) and angular velocities at the shoulder and elbow of the bowing arm.
Muscle activity in right anterior deltoid, biceps brachii and triceps brachii was assessed
during maximal voluntary contractions (MVC) and during the playing task. Data were
analysed for significant differences across the strings and between experience groups.
Results: Elbow flexion/extension ROM was similar across strings for both groups.
Shoulder flexion/extension ROM increaslarger for the experts. Angular velocity changes mirrored changes in ROM. Deltoid was
the most active of the muscles assessed (20% MVC) and displayed a pattern of constant
activation to maintain shoulder abduction. Biceps and triceps were less active (4 - 12%
MVC) and showed a more periodic 'on and off pattern. Novices' muscle activity was
higher in all cases. Experts' muscle activity showed a consistent pattern across strings,
whereas the novices were more irregular. The agonist-antagonist roles of biceps and
triceps during the bowing motion were clearly defined in the expert group, but not as
apparent in the novice group.
Conclusions: Bowing movement appears to be controlled by the shoulder rather
than the elbow as shoulder ROM changed across strings while elbow ROM remained the
same. Shoulder injuries are probably due to repetition as the muscle activity required for
the movement is small. Experts require a smaller amount of muscle activity to perform
the movement, possibly due to more efficient muscle activation patterns as a result of
practice. This quantitative multidisciplinary approach to analysing violinists' movements
can contribute to fuller understanding of both playing demands and injury mechanisms .||en_US