Scapular and Cervical Neuromuscular Control Deficits in Musicians With and Without Playing Injuries.

Background: The art of professionally playing a musical instrument can be physically demanding. Such activity involves maintaining static postures and producing repetitive motions for countless hours of playing time between practice and performances, often with very little rest. More than 50% of musicians will develop upper extremity injuries and pain related to instrument use, which can negatively affect or interrupt their careers. Efficient cervical spine and shoulder girdle neuromuscular control is essential for upper quarter musculoskeletal injury prevention. Neuromuscular control deficits are linked to a higher upper extremity occupational injury incidence in most professions. However, no research to date has investigated if there are differences in scapular and cervical endurance and neuromuscular control between musicians with and without playing-related cervical and upper extremity musculoskeletal disorders. Design: Case-control study Setting: Musical venue and university setting. Participants: Eighty subjects including student musicians from different universities and professional musicians in Tennessee. Methods: Musicians will be consecutively recruited to fill in a questionnaire regarding the presence of cervical and upper extremity PRMSDs. Those subjects with PRMSDs (Yes-PRMSDs) will undergo clinical testing for the presence of scapular dyskinesis and cervical neuromuscular control and endurance deficits using the following tests: (1) cranio-cervical flexion test; (2) scapular dyskinesis test; and (3) deep neck flexor endurance test. Asymptomatic musicians (No-PRMSDs) will be recruited consecutively, matched by gender, type of instrument (string instrument or other) and number of hours played per week and tested following the same protocol. Reliability testing: To determine intrarater reliability prior to data collection, a convenience sample of twenty subjects not included in the study will be evaluated over two days for (1) Cranio-cervical flexion test; (2) Scapular dyskinesis test; and (3) deep neck flexor endurance test. Tests will be repeated with at least a 24-hour interval between testing sessions. Intra-class correlation coefficient (model 3, 2) for the two cervical tests and Kappa statistics model for the scapular dyskinesis test will be calculated for determination of intrarater reliability. Interventions: Subjects will complete a comprehensive demographic questionnaire that includes playing patterns, as well as general health related questions and fitness activities exposure. In a second visit, subjects in both groups will complete a test battery that includes cranio-cervical flexion test, scapular dyskinesis assessment and deep neck flexor endurance test. Blinding of the assessor as to the group in which subjects are members (Yes-PRMSDs versus No-PRMSDs) will be ensured. Purpose: The purposes of this research will be to investigate if there are differences in the presence of: (1) prior injury, playing patterns, and physical fitness habits; (2) scapular dyskinesis; and (3) cervical neuromuscular control and endurance deficits between musicians with and without playing related musculoskeletal Disorders (PRMSDs)