The Effects of Upper-Extremity Plyometric Combined Strength Training in Overhead Athletes With Shoulder Instability

NCT ID: NCT05857540

Last Updated: 2025-05-22

Basic Information

• Recruitment Status: ACTIVE_NOT_RECRUITING
• Clinical Phase: NA
• Total Enrollment: 64 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2023-05-20
• Study Completion Date: 2025-06-30

Brief Summary

The purpose of this randomized controlled trial is to investigate the additional effects of upper extremity plyometric training versus strength training alone in recreational overhead athletes with shoulder instability. The investigators hypothesis that compared to strengthening training alone, plyometric training combined with strengthening training will significantly improve shoulder isokinetic strength, proprioception, scapular kinematics, symptoms of shoulder instability, and shoulder function.

Detailed Description

Background: Shoulder instability is a common problem in active young adults with a wide spectrum ranging from microinstability, subluxation to dislocation. In patients with instability of Stanmore polar type 2 or 3, recurrent shoulder instability may be related to abnormal movement patterns but not result from trauma. Non-operative management is suggested to this subgroup as the first-line treatment. Previous rehabilitation protocols including progressive shoulder muscles strengthening and neuromuscular control training have shown positive effects on functional outcomes in individuals with shoulder instability. Recent protocols for shoulder instability usually include various types of plyometric training to prepare injured athletes to return to sports. Plyometric training in lower extremity has been wildly used for knee injury prevention. In upper extremity, plyometrics also has been shown to improve isokinetic strength, throwing performance, and proprioception in healthy subjects and healthy overhead athletes. However, it is still not well-understood that whether a strengthening training combined with plyometrics would be more effective to improve shoulder neuromuscular control and shoulder function in subjects with instability. The purpose of this study is to investigate the additional effects of upper extremity plyometric training in recreational overhead athletes with anterior shoulder instability. The investigators hypothesis that compared to strengthening training alone, plyometric training combined with strengthening training will significantly improve strength, proprioception, shoulder kinematic and muscle activity, shoulder pain and shoulder function.

Methods: A total of 64 participants with anterior shoulder instability will be randomized to either an experimental group (plyometric and strengthening training) or a control group (strengthening training). Both groups will receive a 50-minute supervised training protocol twice a week for 6 weeks. The primary outcomes include (1) isokinetic assessment of internal and external rotation (peak torque, time to peak torque, and amortization time); (2) proprioception (active and passive joint position sense); (3) seated medicine ball throw test (distance in cm). The secondary outcomes include (1) shoulder pain and instability with 10-cm visual analogue scale (VAS); (2) shoulder function assessed with the Disability of Arm, Shoulder and Hand (DASH) questionnaire; (3) Global rating of change (GRC). GRC will be measured after the end of 12 session of intervention, and all the other outcomes will be measured at baseline and following 12 sessions of exercise training. The two-way repeated measures ANOVAs will be used to compare primary and secondary outcome variables between groups. The significant level was set at 0.05.

Conditions

Glenohumeral Subluxation; Shoulder Subluxation; Shoulder Instability Subluxation Bilateral

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: SINGLE

Study Groups

Plyometric training group

Participants in this group will receive upper extremity plyometric training in body weight or with weight ball and strengthening exercises with band, dumbbell and barbell. The difficulty and intensity of the movement protocol will increase weekly. They will be trained 2 times per week for 6 weeks with an average duration of 50 min per session.

Group Type: EXPERIMENTAL

Plyometric and strengthening exercises

Intervention Type: PROCEDURE

Each session includes 2 upper-extremity plyometric exercises in bodyweight or with weight ball for 15-20 minutes and 4-5 strengthening exercises with band, dumbbell or barbell for 30-35 minutes. The difficulty of the movement protocol will increase weekly. They will be trained 2 times per week for 6 weeks with an average duration of 50 min per session.

Strengthening training group

Participants in this group will receive upper extremity strengthening exercises with band, dumbbell and barbell. The intensity of the movement protocol will increase weekly. They will be trained 2 times per week for 6 weeks with an average duration of 50 min per session.

Group Type: ACTIVE_COMPARATOR

Strengthening exercise

Intervention Type: PROCEDURE

Each session includes 5 upper-extremity strengthening exercises with band, dumbbell or barbell for 50 minutes. The difficulty of the movement protocol will increase weekly. They will be trained 2 times per week for 6 weeks with an average duration of 50 min per session.

Interventions

Plyometric and strengthening exercises

Each session includes 2 upper-extremity plyometric exercises in bodyweight or with weight ball for 15-20 minutes and 4-5 strengthening exercises with band, dumbbell or barbell for 30-35 minutes. The difficulty of the movement protocol will increase weekly. They will be trained 2 times per week for 6 weeks with an average duration of 50 min per session.

Intervention Type: PROCEDURE

Strengthening exercise

Each session includes 5 upper-extremity strengthening exercises with band, dumbbell or barbell for 50 minutes. The difficulty of the movement protocol will increase weekly. They will be trained 2 times per week for 6 weeks with an average duration of 50 min per session.

Intervention Type: PROCEDURE

Eligibility Criteria

Inclusion Criteria

1. Have experience of at least 1 of the following symptoms of shoulder instability during upper extremity movement: (a) pain, clicking, a sense of the shoulder coming apart, (b) dead-arm syndrome, or (c) subluxation of the joint.

2. Self-reported decreased performance or feeling fear to perform shoulder movements during sports or daily activities

3. Positive findings on ≥ 1 of the following 5 tests: load and shift test, apprehension, relocation, & surprise tests, Gagey hyperabduction test, sulcus sign, Feagin test

4. Recreational overhead athletes who keep practicing ≥ 4 hours/week in the recent 1 month and with ≥ 1 year overhead sports experience

Exclusion Criteria

1. Full contact sport athletes

2. Severe shoulder instability with > 5 shoulder dislocations history

3. Obvious shoulder bony/labrum lesion in the dominant side warranted for surgery first as decided by the orthopedic surgeon

4. Previous surgery or fracture in the shoulder area on the dominant side within 1 year

5. Voluntary instability (the ability to deliberately dislocate one's shoulder)

6. During acute phase after shoulder dislocation event

7. Not suitable to start plyometric training yet: Shoulder muscle weakness (manual muscle test <3) or range of motion limitation (<90 abduction, <70 external rotation) in the dominant side

8. Pregnancy

9. Cancer, neck pain, brain & neurological impairment

10. Ehlers-Danlos syndrome or Marfan syndrome

11. Unable to attend 6 weeks supervised training

• Minimum Eligible Age: 20 Years
• Maximum Eligible Age: 40 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

National Yang Ming Chiao Tung University

OTHER

Sponsor Role: lead

Responsible Party

Yin-Liang Lin

Assistant Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Yin-Liang Lin, PhD

Role: PRINCIPAL_INVESTIGATOR

National Yang Ming Chiao Tung University

Locations

National Yang Ming Chiao Tung University

Taipei, Taipei, Taiwan

Countries

Taiwan

Other Identifiers

YM111161F

Identifier Type: -

Identifier Source: org_study_id