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

January 13, 2026 updated by: National Taiwan University Hospital

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.

Study Overview

Status

Completed

Conditions

Detailed Description

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.

Study Type

Observational

Enrollment (Actual)

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

Taiwan
- - Taipei, Taiwan
    - National Taiwan University Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

20 years to 99 years (Adult, Older Adult)

Accepts Healthy Volunteers

Sampling Method

Non-Probability Sample

Study Population

The participants are overhead athletes with scapular dyskinesis (SD) who played overhead sports activities at least 3 hours/week.

Description

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.)

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

What is the study measuring?

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) Time Frame: Through study completion, an average of 10 months	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 Time Frame: Through study completion, an average of 10 months	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 Time Frame: Through study completion, an average of 10 months	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

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

National Taiwan University Hospital

Investigators

Principal Investigator: Jiu-Jenq Lin, National Taiwan University Hospital

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

October 16, 2022

Primary Completion (Actual)

February 23, 2023

Study Completion (Actual)

February 23, 2023

Study Registration Dates

First Submitted

October 12, 2022

First Submitted That Met QC Criteria

January 26, 2023

First Posted (Actual)

February 6, 2023

Study Record Updates

Last Update Posted (Actual)

January 15, 2026

Last Update Submitted That Met QC Criteria

January 13, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

202208053RINA

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Studies a U.S. FDA-regulated device product

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.