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The Effect of Unstable Loads on Scapular Kinematics and Muscle Activation During Overhead Press in Overhead Athletes With Subacromial Pain Syndrome

The Effect of Unstable Loads on Scapular Kinematics and Muscle Activation During Overhead Press in Overhead Athletes With Subacromial Pain Syndrome

Status
Recruiting
Phases
Unknown
Study type
Observational
Source
ClinicalTrials.gov
Registry ID
NCT07646899
Enrollment
27
Registered
2026-06-15
Start date
2024-09-26
Completion date
2026-06-30
Last updated
2026-06-15

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Subacromial Pain Syndrome

Brief summary

The research aims to compare the differences between stable and unstable load conditions during shoulder pressing in overhead athletes with SAPS and to compare the differences between SAPS and healthy athletes with stable and unstable load conditions.

Interventions

BEHAVIORALstable load shoulder press

Participants performed a shoulder press using a barbell loaded at their individual 15-repetition maximum

BEHAVIORALUnstable load shoulder press

Participants performed a shoulder press using a unstable loaded at their individual 15-repetition maximum

Sponsors

National Yang Ming Chiao Tung University
Lead SponsorOTHER

Study design

Observational model
CASE_ONLY
Time perspective
CROSS_SECTIONAL

Eligibility

Sex/Gender
ALL
Age
18 Years to 40 Years
Healthy volunteers
Yes

Inclusion criteria

The inclusion criteria for both the experimental and control groups were as follows: (1) amateur or recreational overhead athletes aged 18-40 years (e.g., volleyball, tennis, baseball); (2) sport participation history of more than 3 years; (3) weekly overhead sport participation of more than 4 hours; (4) ability to meet the minimum loading requirements of the equipment for both stable and unstable conditions, defined as a 15-repetition maximum (15RM) for stable shoulder press of ≥10 kg and unstable shoulder press of ≥8 kg. The individual inclusion criteria for the experimental group were: (1) diagnosis of subacromial pain syndrome, defined as at least 3 positive findings out of 5 clinical tests (Painful Arc test, Neer impingement test, Empty Can test, Hawkins-Kennedy impingement test, and Resisted External Rotation test); (2) Visual Analogue Scale (VAS) score of ≤3 during shoulder press performance; (3) symptoms present on the dominant side. The individual inclusion criteria for the control group were: absence of shoulder pain within the past 6 months, including no pain at the glenohumeral joint, acromioclavicular joint, sternoclavicular joint, scapulothoracic joint, or cervical spine. The

Exclusion criteria

were as follows: (1) history of surgical intervention for fracture or dislocation of the shoulder or elbow joint within the past 6 months; (2) direct trauma to the cervical spine or upper extremity within the past 1 month; (3) shoulder pain or neurological symptoms of cervical origin; (4) any condition preventing the completion of the experimental protocol; (5) bilateral shoulder pain.

Design outcomes

Primary

MeasureTime frameDescription
Scapular kinematics (degrees) during shoulder elevation measured by VIPER™ systemImmediately after the single sessionScapular upward rotation, posterior tilt, and external rotation angles (in degrees) were recorded during shoulder press using the VIPER™ electromagnetic tracking system. Data were collected at 30°, 60°, 90°, and 120° of humeral elevation, and reported as mean values for each angle.
Surface electromyography (TeleMyo2400T G2, Noraxon USA Inc., Scottsdale, AZ, USA)Immediately after the single sessionMuscle activation of upper trapezius, lower trapezius, serratus anterior, anterior deltoid, biceps brachii, triceps brachii, rectus abdominis, erector spinae during shoulder press
Barbell trajectory (measured with camera)Immediately after the single sessionThe trajectory was captured by attaching reflective markers to the end of the barbell and recording kinematic data at a sampling frequency of 60 Hz using a camera.

Secondary

MeasureTime frameDescription
Shoulder average pain intensityImmediately after the single sessionPain 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.

Countries

Taiwan

Contacts

CONTACTYi Chung Tsai, Master
sc969183@gmail.com(886)972877917

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Jun 16, 2026