Glenohumeral Internal Rotation Deficit (GIRD)NCT07372274
Effect of Glenohumeral Internal Rotation Deficit on Shoulder Endurance and Stability in Adolescent Male Volleyball Players
An observational study of Glenohumeral Internal Rotation Deficit (GIRD), run by Saglik Bilimleri Universitesi at 1 site in Turkey (Türkiye).
Trial summary
This study aims to investigate whether glenohumeral internal rotation deficit (GIRD) is associated with shoulder endurance and functional stability in male adolescent volleyball players aged 14 to 18 years who do not have shoulder pain. Read more about this study
- Who is it for?
- Ages 14 to 18 years, men onlyHealthy volunteers can take part
- Conditions the study is for
- Glenohumeral Internal Rotation Deficit (GIRD)
- What is being tested?
- Glenohumeral Rotation ROM, Shoulder Endurance, and Upper Extremity Stability Testing
- How many people
- 52 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 5 Nov 2024to 30 Dec 2025
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 14 to 18 years
- Men only
- Healthy volunteers accepted
- Child, Adult
Study population: The study population consists of adolescent male volleyball players aged 14-18 years with at least 3 years of licensed volleyball experience.
Who may be able to join
- Male adolescent volleyball players aged 14-18 years
- Be a licensed volleyball player for at least 3 years.
- Be male and currently without shoulder symptoms (no current shoulder complaint)
Who cannot join
- Signs of possible shoulder impingement: 3 or more positive results out of 5 clinical shoulder tests (Neer test, Hawkins-Kennedy test, Painful Arc test 60°-120°, infraspinatus weakness, Empty Can test)
- Shoulder pain within the last 6 months.
- A history of shoulder surgery
Trial locations and contacts
1 site in 1 country.
Turkey (Türkiye)1 site
Faculty of Physiotherapy and Rehabilitation, University of Health Sciences
Ankara, Ankara, 06010
About this study
Official title: The Effects of Glenohumeral Internal Rotation Deficit on Posterior Shoulder Endurance and Upper Extremity Stability in Adolescent Male Volleyball Players
This study aims to investigate whether glenohumeral internal rotation deficit (GIRD) is associated with shoulder endurance and functional stability in male adolescent volleyball players aged 14 to 18 years who do not have shoulder pain. GIRD refers to a reduction in internal rotation range of motion of the dominant (spiking) shoulder compared with the non-dominant shoulder and is commonly observed in young athletes participating in overhead sports such as volleyball.
Participants will be divided into two groups based on shoulder range of motion measurements. Athletes with a loss of at least 10 degrees of internal rotation in the dominant shoulder compared to the non-dominant shoulder will be classified as having GIRD, while those without this difference will be classified as not having GIRD. Shoulder internal and external rotation range of motion will be measured using standardized clinical assessment methods.
Read more
Shoulder endurance and upper extremity functional stability will then be evaluated using clinically applicable performance-based tests, including the Shoulder Endurance Test, the Posterior Shoulder Endurance Test, and the Modified Closed Kinetic Chain Upper Extremity Stability Test. The results of these tests will be compared between athletes with and without GIRD.
The main research question of this study is whether the presence of GIRD in asymptomatic adolescent volleyball players is associated with reduced shoulder muscle endurance and decreased functional stability of the upper extremity. The study hypothesizes that athletes with GIRD will demonstrate lower posterior shoulder endurance and poorer upper extremity stability compared to athletes without GIRD.
Read the detailed description
Repetitive overhead sports activities are known to produce sport-specific adaptations in the glenohumeral joint. One of the most commonly observed adaptations is a reduction in glenohumeral internal rotation on the dominant side, referred to as glenohumeral internal rotation deficit (GIRD). Although GIRD has been widely investigated in adult athletes and in relation to shoulder pain and injury, less is known about its functional implications in asymptomatic adolescent athletes.
This study is designed to explore the association between GIRD and shoulder-related functional performance parameters in adolescent volleyball players. The focus of the protocol is on muscle endurance and dynamic upper extremity stability, which are key components of shoulder function during repetitive overhead tasks. The study specifically examines whether alterations in glenohumeral rotation are reflected in measurable differences in performance-based clinical tests, even in the absence of pain or reported injury.
Standardized physical assessment procedures are used to quantify shoulder rotation and functional performance. All measurements are performed by trained assessors using consistent testing protocols to minimize inter-rater and intra-rater variability. Testing is conducted under controlled laboratory conditions to ensure uniformity across participants.
The analytical approach is based on between-group comparisons according to the presence or absence of GIRD. Statistical methods are selected to evaluate differences in endurance and stability outcomes and to quantify the magnitude of these differences. Sample size estimation is based on previously published data examining shoulder endurance and stability outcomes in overhead athletes.
This protocol aims to contribute to the understanding of early functional changes associated with shoulder motion adaptations in adolescent volleyball players and to inform future injury prevention and training strategies in youth overhead sports.
- Being tested
- Glenohumeral Rotation ROM, Shoulder Endurance, and Upper Extremity Stability Testing
- Keywords
- Glenohumeral internal rotation deficit, adolescent athletes, volleyball players
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Glenohumeral Rotation ROM, Shoulder Endurance, and Upper Extremity Stability TestingOther
Participants undergo a standardized shoulder assessment session. Glenohumeral internal and external rotation range of motion is measured using a goniometric clinical procedure with the shoulder positioned in standardized alignment. Functional performance is assessed using a battery of tests including a shoulder endurance test, a posterior shoulder endurance test, and a modified closed kinetic chain upper extremity stability test. All procedures are performed in a controlled laboratory setting by trained assessors following a consistent protocol.
| Study group | Role | What they receive |
|---|---|---|
| Glenohumeral internal rotation deficit (GIRD) Group | GIRD Present (≥10° internal rotation deficit) Receives: Other: Glenohumeral Rotation ROM, Shoulder Endurance, and Upper Extremity Stability Testing | |
| Non-Glenohumeral internal rotation deficit (GIRD) Group | No GIRD (<10° internal rotation deficit) Receives: Other: Glenohumeral Rotation ROM, Shoulder Endurance, and Upper Extremity Stability Testing |
What is being measured
The primary outcome is the main question the study is designed to answer.
Shoulder Endurance Test (SET) Duration
Shoulder endurance measured as time to volitional fatigue (seconds) during the Shoulder Endurance Test. Participants stand with the back against a wall and perform repeated movements from 90° shoulder flexion to 90° abduction with 90° external rotation and back, using a 1-m green TheraBand anchored to achieve ~100% elongation. Cadence is metronome-controlled and progressively increased (60 bpm, then 90, 120, and 150 bpm). Score range: 0 seconds to no upper limit; higher seconds indicate better endurance.
Measured: Through study completion, an average of 1 year
Secondary outcomes (2)
Posterior Shoulder Endurance Test (PSET) Duration
Posterior shoulder endurance measured as time (seconds) the participant can maintain the test position while holding an individually calculated external load. In prone position with the test arm over the table edge, the shoulder is positioned at 90° flexion; the participant elevates the arm to 90° abduction (thumb up) and maintains contact with a level bar apparatus. The test ends if contact is lost or compensatory movements occur. Score range: 0 seconds to no upper limit; higher seconds indicate better posterior shoulder endurance
Measured: through study completion, an average of 1 year
Modified Closed Kinetic Chain Upper Extremity Stability Test (Modified CKCUEST) Score
Upper extremity functional stability measured as the mean number of touches completed in 15 seconds during the Modified Closed Kinetic Chain Upper Extremity Stability Test. Hand placement is standardized using the distance between the acromion processes. From a push-up position, participants alternately touch the dorsal surface of the contralateral hand and return to start as many times as possible. Three trials are performed; the mean of three trials is the score. Score range: 0 touches to no upper limit; higher values indicate better stability.
Measured: through study completion, an average of 1 year
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 Jan 2026
- Study start5 Nov 2024
- Primary completion30 Oct 2025
- Study completion30 Dec 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Glenohumeral Internal Rotation Deficit (GIRD)Studies of the same condition, open and under way.
- More trials run by Saglik Bilimleri UniversitesiThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Cross-sectional
- Enrolment
- 52 participants (actual)
Sponsor and investigators
- Lead sponsor
- Saglik Bilimleri Universitesi
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Seda Uluşahin, Saglik Bilimleri Universitesi
- Investigators
- Seda Bicici Ulusahin, PhD, Principal investigator, Saglik Bilimleri Universitesi
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07372274
- Sponsor's protocol ID
- 2024-534
- Status last verified
- Jan 2026
- First submitted
- 13 Jan 2026
- Last updated
- 28 Jan 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: No plan to share individual participant data (IPD) at this time
Study at a glance
From the registry record, last updated by the sponsor on 28 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effects of Glenohumeral Internal Rotation Deficit on Posterior Shoulder Endurance and Upper Extremity Stability in Adolescent Male Volleyball Players
- ClinicalTrials.gov ID
- NCT07372274
- Acronym / sponsor ID
- 2024-534
- Keywords
- Glenohumeral internal rotation deficit, adolescent athletes, volleyball players
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 52 participants (actual)
- Lead sponsor
- Saglik Bilimleri UniversitesiUniversity, hospital or other
- Study start
- 5 Nov 2024 (actual)
- Primary completion
- 30 Oct 2025 (actual)
- Study completion
- 30 Dec 2025 (actual)
- First posted
- 28 Jan 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study aims to investigate whether glenohumeral internal rotation deficit (GIRD) is associated with shoulder endurance and functional stability in male adolescent volleyball players aged 14 to 18 years who do not have shoulder pain. GIRD refers to a reduction in internal rotation range of motion of the dominant (spiking) shoulder compared with the non-dominant shoulder and is commonly observed in young athletes participating in overhead sports such as volleyball.
Participants will be divided into two groups based on shoulder range of motion measurements. Athletes with a loss of at least 10 degrees of internal rotation in the dominant shoulder compared to the non-dominant shoulder will be classified as having GIRD, while those without this difference will be classified as not having GIRD. Shoulder internal and external rotation range of motion will be measured using standardized clinical assessment methods.
Shoulder endurance and upper extremity functional stability will then be evaluated using clinically applicable performance-based tests, including the Shoulder Endurance Test, the Posterior Shoulder Endurance Test, and the Modified Closed Kinetic Chain Upper Extremity Stability Test. The results of these tests will be compared between athletes with and without GIRD.
The main research question of this study is whether the presence of GIRD in asymptomatic adolescent volleyball players is associated with reduced shoulder muscle endurance and decreased functional stability of the upper extremity. The study hypothesizes that athletes with GIRD will demonstrate lower posterior shoulder endurance and poorer upper extremity stability compared to athletes without GIRD.
Detailed description
Repetitive overhead sports activities are known to produce sport-specific adaptations in the glenohumeral joint. One of the most commonly observed adaptations is a reduction in glenohumeral internal rotation on the dominant side, referred to as glenohumeral internal rotation deficit (GIRD). Although GIRD has been widely investigated in adult athletes and in relation to shoulder pain and injury, less is known about its functional implications in asymptomatic adolescent athletes.
This study is designed to explore the association between GIRD and shoulder-related functional performance parameters in adolescent volleyball players. The focus of the protocol is on muscle endurance and dynamic upper extremity stability, which are key components of shoulder function during repetitive overhead tasks. The study specifically examines whether alterations in glenohumeral rotation are reflected in measurable differences in performance-based clinical tests, even in the absence of pain or reported injury.
Standardized physical assessment procedures are used to quantify shoulder rotation and functional performance. All measurements are performed by trained assessors using consistent testing protocols to minimize inter-rater and intra-rater variability. Testing is conducted under controlled laboratory conditions to ensure uniformity across participants.
The analytical approach is based on between-group comparisons according to the presence or absence of GIRD. Statistical methods are selected to evaluate differences in endurance and stability outcomes and to quantify the magnitude of these differences. Sample size estimation is based on previously published data examining shoulder endurance and stability outcomes in overhead athletes.
This protocol aims to contribute to the understanding of early functional changes associated with shoulder motion adaptations in adolescent volleyball players and to inform future injury prevention and training strategies in youth overhead sports.
Study design
- Observational model
- Cohort
- Time perspective
- Cross-sectional
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Glenohumeral internal rotation deficit (GIRD) Group | – | Other: Glenohumeral Rotation ROM, Shoulder Endurance, and Upper Extremity Stability TestingGIRD Present (≥10° internal rotation deficit) |
| Non-Glenohumeral internal rotation deficit (GIRD) Group | – | Other: Glenohumeral Rotation ROM, Shoulder Endurance, and Upper Extremity Stability TestingNo GIRD (<10° internal rotation deficit) |
Who may qualify
- Ages
- 14 to 18 years
- Sex
- Male only
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult
- Study population
- The study population consists of adolescent male volleyball players aged 14-18 years with at least 3 years of licensed volleyball experience.
Key inclusion criteria (3 listed)
- Male adolescent volleyball players aged 14-18 years
- Be a licensed volleyball player for at least 3 years.
- Be male and currently without shoulder symptoms (no current shoulder complaint)
Key exclusion criteria (3 listed)
- Signs of possible shoulder impingement: 3 or more positive results out of 5 clinical shoulder tests (Neer test, Hawkins-Kennedy test, Painful Arc test 60°-120°, infraspinatus weakness, Empty Can test)
- Shoulder pain within the last 6 months.
- A history of shoulder surgery
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Glenohumeral Rotation ROM, Shoulder Endurance, and Upper Extremity Stability TestingParticipants undergo a standardized shoulder assessment session. Glenohumeral internal and external rotation range of motion is measured using a goniometric clinical procedure with the shoulder positioned in standardized alignment. Functional performance is assessed using a battery of tests including a shoulder endurance test, a posterior shoulder endurance test, and a modified closed kinetic chain upper extremity stability test. All procedures are performed in a controlled laboratory setting by trained assessors following a consistent protocol. | Other | Glenohumeral internal rotation deficit (GIRD) Group, Non-Glenohumeral internal rotation deficit (GIRD) Group |
Primary outcome
Shoulder Endurance Test (SET) Duration
Time frame: Through study completion, an average of 1 year
Shoulder endurance measured as time to volitional fatigue (seconds) during the Shoulder Endurance Test. Participants stand with the back against a wall and perform repeated movements from 90° shoulder flexion to 90° abduction with 90° external rotation and back, using a 1-m green TheraBand anchored to achieve ~100% elongation. Cadence is metronome-controlled and progressively increased (60 bpm, then 90, 120, and 150 bpm). Score range: 0 seconds to no upper limit; higher seconds indicate better endurance.
2 secondary outcomes
Posterior Shoulder Endurance Test (PSET) Duration
Time frame: through study completion, an average of 1 year
Modified Closed Kinetic Chain Upper Extremity Stability Test (Modified CKCUEST) Score
Time frame: through study completion, an average of 1 year
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 28 Jan 2026.
- Individual participant dataSharing planned: No. No plan to share individual participant data (IPD) at this time
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Seda Bicici Ulusahin, PhD principal investigator
Saglik Bilimleri Universitesi
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Glenohumeral Internal Rotation Deficit (GIRD), run by Saglik Bilimleri Universitesi at 1 site in Turkey (Türkiye).
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 28 Jan 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Turkey (Türkiye). Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Shoulder Endurance Test (SET) Duration (time frame: Through study completion, an average of 1 year). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 28 Jan 2026.