Risk Factors of Shoulder Injuries in Youth Volleyball Players

Shoulder injuries are usual in volleyball players. Nowadays, few prospective studies assessed risk factors of shoulder injuries in this sport. So, the objective of this study is to assess the risk factors of injuries in youth volleyball players. For that purpose, the following factors will be taken into consideration : shoulder internal/external rotators strength, shoulder range of motion, scapular dyskinesis, functional tests (medicine ball throw and upper quarter Y balance test), training load and psychosocial factors (POMS questionnaire).

About 100 youth volleyball players (13-20 years), playing at least 8 hours volleyball in a week will be included in the study. At the beginning of the 2019-2020 season, they will have to take part at the following evaluations : 1. Clinical evaluation : * Scapular dyskinesis assessment (normal, subtle abnormality and obvious abnormality) * Scapular upward rotation at 0°, 45°,90° and 120° with an inclinometer. * Rounded shoulder posture * Posterior shoulder stiffness * Internal/external rotation range of motion (at 90° of abduction) 2. Medicine ball throw : From a cocking position, players have to throw a 800g medicine ball as far as possible (3 trials). Only the best result will be retained for analysis. Volunteers have 2 minutes of rest between trials. 3. Upper Quarter Y Balance Test : In a facial drop position, the purpose of this test is to bring the plastic board as far as possible in the 3 directions (supero-lateral, infero-lateral, medial). 3 trials are performed by each subject and only the best test is kept for analysis. A rest period of one minute is provided between tests to avoid fatigue. 4. Strength assessment (isokinetic test) : Internal and external rotators strength (concentric 60°/s, eccentric 60°/s and concentric 240°/s) are measured with an isokinetic device (Cybex Norm) at 90° of abduction. 5. Psychosocial factors assessment : Players will have to fill in POMS questionnaire (65 questions), that give information about stress and well-being. After that, players will be followed during all the 2019-2020 season and will have to fill in a form each month about the potential injuries they had during the previous month.