Posterior Shoulder Tightness
Conditions
Keywords
Posterior Shoulder Tightness, Shoulder Muscle Stiffness, Overhead Athletes
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.
Detailed description
Repetitive overhead sports activities lead to sport-specific adaptations in the glenohumeral joint and the surrounding soft tissues. One of the most common adaptations is posterior shoulder tightness, which has been associated with reduced glenohumeral range of motion, altered scapulohumeral rhythm, impaired shoulder biomechanics, and an increased risk of shoulder injury. In addition, changes in the mechanical properties of the posterior shoulder muscles may adversely affect shoulder function and athletic performance. Therefore, identifying effective, evidence-based interventions to reduce posterior shoulder tightness is of considerable clinical importance. Focal vibration is a non-invasive therapeutic intervention that stimulates muscle spindles, enhances proprioceptive feedback, improves neuromuscular control, and may alter the mechanical properties of soft tissues. However, evidence regarding the acute effects of focal vibration on posterior shoulder tightness, muscle stiffness, and glenohumeral range of motion in overhead athletes remains limited. This study is designed as a single-blind, randomized, sham-controlled trial to investigate the acute effects of focal vibration on posterior shoulder tightness, posterior shoulder muscle stiffness, and glenohumeral internal and external rotation range of motion in overhead athletes. Participants will be randomly assigned to either the focal vibration group or the sham control group using block randomization. All assessments will be performed by the same investigator using standardized testing procedures immediately before and immediately after a single intervention session. Posterior shoulder tightness will be assessed using the Horizontal Adduction Test. The stiffness of the posterior deltoid, infraspinatus, and teres minor muscles will be measured using the IndentoPRO digital tissue indentometer. Passive glenohumeral internal and external rotation range of motion will be assessed using the GYKO inertial sensor. Between-group and within-group differences will be analyzed using appropriate statistical methods. This study aims to provide evidence regarding the acute effects of focal vibration on posterior shoulder tightness and the mechanical properties of posterior shoulder muscles, thereby contributing to evidence-based clinical practice in sports rehabilitation, performance enhancement, and shoulder injury prevention.
Interventions
DEVICEFocal Vibration
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.
DEVICESham Focal Vibration
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.
Sponsors
Saglik Bilimleri Universitesi
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Subject)
Eligibility
Sex/Gender
ALL
Age
18 Years to 25 Years
Healthy volunteers
No
Inclusion criteria
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.
Exclusion criteria
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.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Posterior Shoulder Tightness (Horizontal Adduction Test) | Immediately before and immediately after a single intervention session | 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. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Posterior Shoulder Muscle Stiffness | Immediately before and immediately after a single intervention session | Posterior shoulder muscle stiffness will be assessed using the IndentoPRO digital tissue indentometer. Stiffness of the posterior deltoid, infraspinatus, and teres minor muscles will be measured under standardized conditions with participants in a relaxed position. Muscle stiffness will be recorded in N/mm, with higher values indicating greater tissue stiffness and lower values indicating reduced muscle stiffness. |
| Glenohumeral Internal and External Rotation Range of Motion | Immediately before and immediately after a single intervention session | Passive glenohumeral internal and external rotation range of motion will be assessed using the GYKO inertial sensor. Measurements will be performed with participants in the supine position, the shoulder abducted to 90° and the elbow flexed to 90°. The scapula will be stabilized during testing to ensure standardized measurements. Range of motion will be recorded in degrees (°). Higher values indicate greater glenohumeral rotational mobility. |
Countries
Turkey (Türkiye)
Outcome results
None listed