Physical Performance and 3D Shoulder Kinematics of Asymptomatic Unilateral/Bilateral Overhead Athletes and Non-athletes

Physical Performance and 3D Shoulder Kinematics of Asymptomatic Unilateral/Bilateral Overhead Athletes and Non-athletes

This study compares the performance and 3-dimensional shoulder kinematics between sides in unilateral overhead-throwers (volleyball attackers), bilateral overhead athletes (swimmers) and non-athletes during two physical performance measures of the upper extremity, one in an open kinetic chain position (unilateral seated shot put test) and the other in a closed kinetic chain position (upper quarter Y balance test)

3-dimensional shoulder kinematics (e.g., scapular angular position/displacement) at key events of each test will be described and compared across sides and groups. For the unilateral seated shot put test, the events are based on humeral motion: a) initiation of humeral motion, b) maximal humeral flexion, c) end of humeral motion. For the upper quarter Y balance test the events are the a) initiation of free hand motion on "GO", b) maximal reach on the medial direction, c) maximal reach on superolateral direction, and d) maximal reach on the inferolateral direction (kinematics measured on the stance upper extremity). The best of 3 maximal-effort trials on each side will be used for analysis. Warm-up exercises and two submaximal practice trials will be performed for preparation for maximal efforts and familiarization with the tests. A rest period of at least one minute between trials will be given to guarantee good physiological conditions to maximally perform. Further resting time will be allowed, if necessary, upon request of the participant.

Inclusion Criteria:

• Perform at least 150 degrees of arm elevation

Exclusion Criteria:

• history of shoulder dislocation
• surgery in the upper extremity ≥ 6 months
• injury in the past month
• evident abnormalities in posture and movement of the upper body quadrant
• pain at the time of testing