Acute Effects of Focal Vibration on Posterior Shoulder Tightness and Tissue Stiffness in Overhead Athletes

NCT07757945 | Active Not Recruiting

• 1 other identifier: 2026-013
• Study Type: interventional
• Target: 36
• Locations: 1 country
• Sites: 1

Brief Summary

This study aims to investigate the acute effects of focal vibration on posterior shoulder tightness, posterior shoulder muscle stiffness, and glenohumeral range of motion in overhead athletes. A total of 36 overhead athletes aged 18-25 years who have regularly participated in overhead sports for at least four years will be included. Participants will be randomly allocated to either the focal vibration group or the sham control group using block randomization. All outcome assessments will be performed immediately before and immediately after a single intervention session. The primary outcome measure is posterior shoulder tightness, assessed using the Horizontal Adduction Test. Secondary outcome measures include posterior shoulder muscle stiffness, assessed using the IndentoPRO digital tissue indentometer, and passive glenohumeral internal and external rotation range of motion, measured using the GYKO inertial sensor. The primary research question is whether focal vibration has an acute effect on posterior shoulder tightness, muscle stiffness, and glenohumeral range of motion in overhead athletes. It is hypothesized that participants receiving focal vibration will demonstrate greater reductions in posterior shoulder tightness and muscle stiffness, as well as greater improvements in glenohumeral range of motion, compared with those receiving the sham intervention.

Conditions

Posterior Shoulder Tightness

Keywords

Posterior Shoulder Tightness; Shoulder Muscle Stiffness; Overhead Athletes

Outcome Measures

Primary Outcomes (1)

• Posterior Shoulder Tightness (Horizontal Adduction Test)

  Posterior shoulder tightness will be assessed using the Horizontal Adduction Test. Participants will lie in the supine position while the scapula is stabilized by the examiner. The shoulder will be passively moved into horizontal adduction until the first point of scapular movement is detected. The horizontal adduction angle will be measured using a digital inclinometer. Lower values indicate greater posterior shoulder tightness, whereas higher values indicate improved shoulder flexibility.

  Immediately before and immediately after a single intervention session

Secondary Outcomes (2)

• Posterior Shoulder Muscle Stiffness

  Immediately before and immediately after a single intervention session

• Glenohumeral Internal and External Rotation Range of Motion

  Immediately before and immediately after a single intervention session

Study Arms (2)

Experimental: Focal Vibration Group

EXPERIMENTAL

Focal Vibration Participants receive a single session of focal vibration applied to the posterior shoulder muscles using a focal vibration device. The intervention is administered according to a standardized protocol. Posterior shoulder tightness, posterior shoulder muscle stiffness, and passive glenohumeral internal and external rotation range of motion are assessed immediately before and immediately after the intervention.

Device: Focal Vibration

Sham Comparator: Sham Focal Vibration Group

SHAM COMPARATOR

Sham Comparator: Sham Focal Vibration Participants receive a single session of sham focal vibration using the same device and treatment setup without delivering therapeutic vibration. Outcome measures, including posterior shoulder tightness, posterior shoulder muscle stiffness, and passive glenohumeral internal and external rotation range of motion, are assessed immediately before and immediately after the sham intervention using the same standardized protocol.

Device: Sham Focal Vibration

Interventions

Focal Vibration DEVICE

A standardized single-session focal vibration intervention applied to the posterior shoulder muscles using fixed vibration parameters. The protocol is designed to evaluate the immediate effects of focal vibration on posterior shoulder tightness and related shoulder functions in overhead athletes and includes a sham-controlled comparison to distinguish treatment effects from placebo.

Also known as: Focal vibration therapy

Experimental: Focal Vibration Group

Sham Focal Vibration DEVICE

The sham focal vibration intervention is performed using the same device, application duration, and application site as the active intervention. However, the device is configured not to deliver therapeutic vibration. This approach is intended to maintain participant blinding and to determine whether the observed effects are attributable to focal vibration rather than placebo effects.

Sham Comparator: Sham Focal Vibration Group

Eligibility Criteria

• Age: 18 Years - 25 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64)

You may qualify if:

• Aged between 18 and 25 years. Regular participation in an overhead sport for at least 4 years. Participating in regular training at least 4 times per week. Willing to participate voluntarily in the study and able to provide written informed consent.

You may not qualify if:

• History of shoulder surgery within the previous 6 months. History of shoulder, neck, or upper extremity injury within the previous 3 months.
• Participation in intense upper extremity training within the previous 48 hours. Presence of infection, skin lesions, or open wounds around the shoulder region. Diagnosis of a systemic rheumatologic or neurological disease. Unwillingness to participate in the study or refusal to provide written informed consent.

Sponsors & Collaborators

• Saglik Bilimleri Universitesi: lead

Study Sites (1)

Faculty of Physiotherapy and Rehabilitation, University of Health Sciences Ankara

Ankara, Turkey (Türkiye)

Location

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator, PT PhD

Study Record Dates

• First Submitted: August 6, 2026
• First Posted: August 11, 2026
• Study Start: February 5, 2026
• Primary Completion (Estimated): August 30, 2026
• Study Completion (Estimated): September 15, 2026
• Last Updated: August 11, 2026

Record last verified: 2026-08

Data Sharing

• IPD Sharing: Will not share

Locations

TU (1)