The Effects of Eccentric-focused Exercise on Posterior Shoulder Tightness in Symptomatic Overhead Athletes

Study Overview
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Brief Summary
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The aim of this study is to investigate the effects of shoulder eccentric exercise training on shoulder mobility, rotator cuff strength, pain and dysfunction, scapular kinematics and muscle activation in symptomatic overhead athletes with posterior shoulder tightness.

Detailed Description
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Overhead athletes commonly have posterior shoulder tightness due to repetitively high tensile loading during overhead throwing. However, intervention studies focused on posterior shoulder tightness in people with subacromial pain are still limited. Additionally, eccentric exercise was thought to improve the eccentric strength and neuromuscular control of posterior shoulder muscles to endure repetitively eccentric loading, which may improve posterior shoulder tightness and decrease the risk of subacromial pain. Nevertheless, no previous study investigated the influence of eccentric exercise on posterior shoulder tightness in overhead athletes. The aim of this study is to investigate the effects of shoulder eccentric exercise training on shoulder mobility, rotator cuff strength, pain and dysfunction, scapular kinematics and muscle activation in symptomatic overhead athletes with posterior shoulder tightness.

Official Title
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The Effects of Eccentric-focused Exercise on Shoulder Mobility, Rotator Cuff Strength, Pain and Dysfunction, Scapular Kinematics and Muscle Activation in Symptomatic Overhead Athletes With Posterior Shoulder Tightness

Conditions
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Posterior Shoulder Tightness

Intervention / Treatment
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* Other: Eccentric-focused exercises
* Other: Stretching exercises
* Other: Hot pack
* Other: Massage


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Participate in overhead sports over 4 hours per week Age between 20 to 50 years old Glenohumeral joint range of motion deficit: Shoulder internal rotation loss more than 15 degrees compared to the non-dominant side and total arc of motion loss more than 5 degrees or/and horizontal adduction range of motion lo more than 15 degrees compared to the non-dominant side Shoulder impingement syndrome criteria Exclusion Criteria: History of shoulder dislocation, fracture and operation History of direct contact in upper extremities or cervical region in the past one month Shoulder pain or neurological symptom caused by cervical problem VAS more than 5 during shoulder elevation Receive treatment for posterior shoulder tightness in the past 3 months

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 50 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Eccentric-focused exercise group<br>Three eccentric-focused exercises addition to the general treatment group | Other: Eccentric-focused exercises<br>* Three eccentric-focused exercises: Shoulder external rotator eccentric contraction in shoulder abduction 90 degree Shoulder external rotator eccentric contraction in shoulder abduction 0 degree Shoulder abductor eccentric contraction in shoulder abduction 90 degree<br>Other: Stretching exercises<br>* Modified sleeper stretch Modified cross-body stretch<br>Other: Hot pack<br>* Hot pack application on shoulder region<br>Other: Massage<br>* Massage for upper trapezius<br>|
| Active Comparator: General treatment group<br>hot pack application on shoulder region upper trapezius massage two stretching exercises (modified sleeper stretch and modified cross-body stretch) | Other: Stretching exercises<br>* Modified sleeper stretch Modified cross-body stretch<br>Other: Hot pack<br>* Hot pack application on shoulder region<br>Other: Massage<br>* Massage for upper trapezius<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Shoulder range of motion (measured with goniometer) | Shoulder external rotation, internal rotation, horizontal adduction range of motion in shoulder flexion 90 degrees | 4 weeks | 
| Rotator cuff functional strength ratio (Pro 4, Biodex Medical Systems, Inc., Shirley, NY, USA) | Eccentric strength of shoulder external rotator and concentric strength of shoulder internal rotator are measured with isokinetic | 4 weeks | 
| Shoulder pain | Pain is measured with Visual Analogue scale (VAS) Score range from 0 to 10. Scoring of 0 represents no pain and scoring of 10 represents pain as bad as it could possibly be. | 4 weeks | 
| Shoulder function | Shoulder function is measured with Disability of the Arm, Shoulder and Hand questionnaire (DASH) Score range from 0 to 100. The higher of the score, the more disability. | 4 weeks | 
| Shoulder endurance test | Participants will be instructed to execute a shoulder endurance test with the theraband®. Participants are asked to place their tested arm in a shoulder forward flexion 90-degree position, holding a 1-m long theraband® fixed at shoulder height on a graduated stick. Then, they are asked to pull the theraband® from the starting position to a 90-90 ending position at an alternated cadence given by a metronome. Males were asked to pull a green theraband® (2.1 kg) and females a red theraband ® (1.7 kg). | 4 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Electromagnetic tracking system (Liberty electromagnetic tracking system, Polhemus , Colchester, VT,) | Scapular kinematics during shoulder elevation task in scapular plane | 4 weeks | 
| Surface electromyography (TeleMyo 2400T G2, Noraxon USA Inc., Scottsdale, AZ, USA) | Muscle activation of infraspinatus, upper trapezius, lower trapezius and serratus anterior during shoulder elevation task in scapular plane | 4 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Posterior shoulder tightness, Eccentric exercise, Shoulder impingement syndrome