Effects of Ai Chi on Scapular Muscle Activation in Overhead Athletes With Scapular Dyskinesis

Study Overview
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Brief Summary
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Scapular dyskinesis (SD) is common in overhead athletes and negatively influence the athletes' performance, increasing the risk of shoulder injury. The kinetic chain (KC) exercises for SD rehabilitation that emphasize importance of core strength and scapula stability during skillful performance. Ai Chi, the aquatic exercises performed in functional positions, which are adequate for power transfer of KC. This study will investigate the effect of KC-based water exercises, Ai Chi, on scapular muscles in overhead athletes with SD.

Detailed Description
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The purpose of this study is to investigate muscle activations of the upper trapezius (UT), lower trapezius (LT), serratus anterior (SA), latissimus dorsi (LD), and muscle balance ratios of UT/LT, UT/SA I in overhead athletes with SD via KC-based exercise in water and on land. KC-based exercises including the movement patterns of Ai Chi which consist of shoulder flexion/ extension, horizontal abduction/ adduction, internal and external rotation, scapular protraction/retraction combined with spinal rotation.

Official Title
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Effects of Ai Chi on Scapular Muscle Activation in Overhead Athletes With Scapular Dyskinesis

Conditions
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Scapular Dyskinesis, Athletic Injuries, Muscle Weakness, Overuse Injury

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: The participants are overhead athletes with scapular dyskinesis (SD) who played overhead sports activities at least 3 hours/week. Exclusion Criteria: the individuals who have shoulder/neck pain in recent 3 months (VAS >7/10) severe shoulder trauma (the collision shoulder, shoulder sprains or strains) severe scoliosis (Cobb angle > 25 degrees) surgery of upper extremity (the shoulder, cervical spine and elbow) or cervical spine peripheral nerve injury or neurological disease (impaired sensation or motor function: numbness, tingle, muscle weakness) body mass index (BMI) >25 infectious disease (upper respiratory tract infection, skin infection, etc.)

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 99 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage of maximal voluntary isometric contraction of upper trapezius (UT), lower trapezius (LT), serratus anterior (SA), latissimus dorsi (LD) | The muscle activity of UT, LT, SA and LD of the dominant hand will be recorded for 3 trials of each exercises with 3-seconds concentric phase and 3-seconds eccentric phase. There is a 3-second rest between trails and one-minute rest between exercises. | Through study completion, an average of 10 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Muscle balance ratio of UT/SA | The muscle balance ratio will be calculated to represent the conditions of these force couples in scapular region. | Through study completion, an average of 10 months | 
| Muscle balance ratio of UT/LT | The muscle balance ratio will be calculated to represent the conditions of these force couples in scapular region. | Through study completion, an average of 10 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Ai Chi, Hydrotherapy, Scapular dyskinesis, Overhead athletes, muscle balance, kinetic chain