Volleyball PlayerNCT07784530
Eye-Hand Cross-Dominance and Upper Extremity Performance in Volleyball Players
An observational study of Volleyball Player, run by Istinye University at 1 site in Turkey (Türkiye).
Trial summary
Eye and hand dominance may influence visuomotor coordination, motor control, and upper extremity performance in athletes. Crossed eye-hand dominance occurs when the dominant eye and dominant hand are located on opposite sides of the body. Read more about this study
- Who is it for?
- Ages 18 to 30 yearsHealthy volunteers can take part
- Conditions the study is for
- Volleyball Player
- What is being tested?
- Volleyball Players With Crossed Eye-Hand Dominance and Volleyball Players Without Crossed Eye-Hand Dominance
- How many people
- 30 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 30 Aug 2026to 30 Nov 2026
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
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 18 to 30 years
- All sexes
- Healthy volunteers accepted
- Adult
Study population: Male and female volleyball players aged 18 to 30 years who have regularly participated in volleyball for at least three years and currently train at least three days per week will be recruited.
Who may be able to join
- Aged between 18 and 30 years.
- Male or female volleyball player.
- At least three years of active volleyball participation.
- Currently training at least three days per week.
- No upper extremity injury within the previous six months.
- Normal or corrected-to-normal visual acuity with eyeglasses or contact lenses.
- Willing to participate and able to provide written informed consent.
Who cannot join
- History or presence of an acute or chronic musculoskeletal disorder that may affect study assessments.
- Presence of a neurological or vestibular system disorder.
- Presence of visual field loss, strabismus, or a severe refractive error that cannot be adequately corrected.
- History of shoulder, elbow, or hand surgery within the previous six months.
- Not currently participating regularly in volleyball or structured exercise.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Turkey (Türkiye)1 site, 1 recruiting
- Recruiting
Istinye University
Istanbul, 34010
Kubra Kardes, Asst.Prof, 05387115631, kubrakoce@gmail.com
About this study
Official title: Comparison of Upper Extremity Muscle Strength and Motor Performance Between Volleyball Players With and Without Crossed Eye-Hand Dominance
Eye and hand dominance may influence visuomotor coordination, motor control, and upper extremity performance in athletes. Crossed eye-hand dominance occurs when the dominant eye and dominant hand are located on opposite sides of the body. However, evidence regarding the relationship between crossed eye-hand dominance and upper extremity performance in volleyball players remains limited.
This observational cross-sectional study aims to compare upper extremity muscle strength and motor performance between volleyball players with and without crossed eye-hand dominance. Participants' eye and hand dominance will be determined using standardized assessments. Upper extremity muscle strength and motor performance outcomes will then be measured and compared between the two groups.
- Conditions
- Volleyball Player
- Being tested
- Volleyball Players With Crossed Eye-Hand Dominance, Volleyball Players Without Crossed Eye-Hand Dominance
- Keywords
- Eye-Hand Dominance, Volleyball Players, Upper Extremity Performance
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Volleyball Players With Crossed Eye-Hand DominanceOther
Volleyball players whose dominant eye and dominant hand are on opposite sides of the body. For example, right-eye dominance with left-hand dominance or left-eye dominance with right-hand dominance. Participants will undergo upper extremity muscle strength and motor performance assessments. No intervention will be administered.
Volleyball Players Without Crossed Eye-Hand DominanceOther
Volleyball players whose dominant eye and dominant hand are on the same side of the body. For example, right-eye dominance with right-hand dominance or left-eye dominance with left-hand dominance. Participants will undergo the same upper extremity muscle strength and motor performance assessments. No intervention will be administered.
| Study group | Role | What they receive |
|---|---|---|
| Group 1: Volleyball Players With Crossed Eye-Hand Dominance | Not described Receives: Other: Volleyball Players With Crossed Eye-Hand Dominance | |
| Group 2: Volleyball Players Without Crossed Eye-Hand Dominance | Not described Receives: Other: Volleyball Players Without Crossed Eye-Hand Dominance |
What is being measured
The primary outcome is the main question the study is designed to answer.
Dominant Eye
Eye dominance will be determined using the Miles Test. The participant will focus on a distant target with both eyes open and will then close each eye separately. The eye with which the target remains centered will be classified as the dominant eye. Eye dominance will be used with hand dominance to classify participants as having crossed or non-crossed eye-hand dominance.
Measured: 4 weeks
Bilateral Shoulder Muscle Strength
Bilateral shoulder flexion, extension, and abduction muscle strength will be measured using a validated handheld myometer. Measurements will be recorded separately for the right and left sides. Higher force values indicate greater shoulder muscle strength, whereas lower values indicate lower muscle strength.
Measured: 4 weeks
Bilateral Elbow Muscle Strength
Bilateral elbow flexion and extension muscle strength will be measured using a validated handheld myometer. Measurements will be recorded separately for the right and left sides. Higher force values indicate greater elbow muscle strength, whereas lower values indicate lower muscle strength.
Measured: 4 weeks
Bilateral Handgrip Strength
Handgrip strength will be measured bilaterally using a digital hand dynamometer. Three measurements will be performed for each hand, and the mean value will be recorded. Higher values indicate greater handgrip strength, whereas lower values indicate lower handgrip strength.
Measured: 4 weeks
Hand-Eye Coordination
Hand-eye coordination will be assessed using the Alternate-Hand Wall Toss Test. The participant will throw a ball against a wall with one hand, catch it with the opposite hand, and repeat the sequence by alternating hands. The total number of successful throws and catches completed within 30 seconds will be recorded. A higher number indicates better hand-eye coordination and motor performance, whereas a lower number indicates poorer performance.
Measured: 4 weeks
Secondary outcomes (5)
Medicine Ball Throw Distance
Upper extremity explosive power will be assessed using the Medicine Ball Throw Test. The participant will sit with the back supported against a wall and the legs extended and will throw the medicine ball as far as possible. The longest valid throwing distance will be recorded in meters. A longer distance indicates greater upper extremity explosive power.
Measured: 4 weeks
Closed Kinetic Chain Upper Extremity Stability Test Score
Upper extremity functional stability, strength, power, and endurance will be assessed using the Closed Kinetic Chain Upper Extremity Stability Test. The participant will assume a push-up position with the hands placed on two markers positioned 90 centimeters apart. The total number of valid alternating touches performed within the specified test period will be recorded. A higher number of touches indicates better upper extremity functional performance and stability.
Measured: 4 weeks
Scapular Muscular Endurance Time
Scapular stabilizer muscle endurance will be assessed using the Scapular Muscular Endurance Test. An appropriately sized wooden rod will be positioned between the participant's elbows while the scapulae are maintained in a neutral position. The duration for which the participant can maintain the standardized position will be recorded in seconds. A longer duration indicates greater scapular muscular endurance.
Measured: 4 weeks
Upper Quarter Y-Balance Test Reach Distance
Upper extremity and trunk balance, mobility, and stability will be assessed using the Upper Quarter Y-Balance Test. Testing will begin with the non-dominant hand as the reaching hand. Maximum reach distances in the medial, inferolateral, and superolateral directions will be recorded. Greater reach distances and higher composite scores indicate better upper extremity dynamic balance and functional stability.
Measured: 4 weeks
Light-Based Reaction Time
Reaction time and neuromuscular control will be assessed using the BlazePod light-based reaction system. Participants will respond to randomly activated visual stimuli according to a standardized testing protocol. Reaction time will be recorded in milliseconds. A shorter reaction time indicates faster visual-motor responses, whereas a longer reaction time indicates slower responses.
Measured: 4 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Aug 2026
- Study start30 Aug 2026
- Primary completion15 Nov 2026 (estimated)
- Study completion30 Nov 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Volleyball PlayerStudies of the same condition, open and under way.
- 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
- Case crossover
- Time perspective
- Cross-sectional
- Enrolment
- 30 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Istinye University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Kubra Kardes, Istinye University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07784530
- Sponsor's protocol ID
- 2026/01
- Status last verified
- Sep 2026
- First submitted
- 21 Aug 2026
- Last updated
- 1 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 1 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Comparison of Upper Extremity Muscle Strength and Motor Performance Between Volleyball Players With and Without Crossed Eye-Hand Dominance
- ClinicalTrials.gov ID
- NCT07784530
- Acronym / sponsor ID
- 2026/01
- Conditions
- Volleyball Player
- Keywords
- Eye-Hand Dominance, Volleyball Players, Upper Extremity Performance
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 30 participants (estimated)
- Lead sponsor
- Istinye UniversityUniversity, hospital or other
- Study start
- 30 Aug 2026 (actual)
- Primary completion
- 15 Nov 2026 (estimated)
- Study completion
- 30 Nov 2026 (estimated)
- First posted
- 25 Aug 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.
Eye and hand dominance may influence visuomotor coordination, motor control, and upper extremity performance in athletes. Crossed eye-hand dominance occurs when the dominant eye and dominant hand are located on opposite sides of the body. However, evidence regarding the relationship between crossed eye-hand dominance and upper extremity performance in volleyball players remains limited.
This observational cross-sectional study aims to compare upper extremity muscle strength and motor performance between volleyball players with and without crossed eye-hand dominance. Participants' eye and hand dominance will be determined using standardized assessments. Upper extremity muscle strength and motor performance outcomes will then be measured and compared between the two groups.
Study design
- Observational model
- Case crossover
- Time perspective
- Cross-sectional
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Group 1: Volleyball Players With Crossed Eye-Hand Dominance | – | Other: Volleyball Players With Crossed Eye-Hand Dominance |
| Group 2: Volleyball Players Without Crossed Eye-Hand Dominance | – | Other: Volleyball Players Without Crossed Eye-Hand Dominance |
Who may qualify
- Ages
- 18 to 30 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
- Study population
- Male and female volleyball players aged 18 to 30 years who have regularly participated in volleyball for at least three years and currently train at least three days per week will be recruited.
Key inclusion criteria (7 listed)
- Aged between 18 and 30 years.
- Male or female volleyball player.
- At least three years of active volleyball participation.
- Currently training at least three days per week.
- No upper extremity injury within the previous six months.
Key exclusion criteria (5 listed)
- History or presence of an acute or chronic musculoskeletal disorder that may affect study assessments.
- Presence of a neurological or vestibular system disorder.
- Presence of visual field loss, strabismus, or a severe refractive error that cannot be adequately corrected.
- History of shoulder, elbow, or hand surgery within the previous six months.
- Not currently participating regularly in volleyball or structured exercise.
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 |
|---|---|---|
| Volleyball Players With Crossed Eye-Hand DominanceVolleyball players whose dominant eye and dominant hand are on opposite sides of the body. For example, right-eye dominance with left-hand dominance or left-eye dominance with right-hand dominance. Participants will undergo upper extremity muscle strength and motor performance assessments. No intervention will be administered. | Other | Group 1: Volleyball Players With Crossed Eye-Hand Dominance |
| Volleyball Players Without Crossed Eye-Hand DominanceVolleyball players whose dominant eye and dominant hand are on the same side of the body. For example, right-eye dominance with right-hand dominance or left-eye dominance with left-hand dominance. Participants will undergo the same upper extremity muscle strength and motor performance assessments. No intervention will be administered. | Other | Group 2: Volleyball Players Without Crossed Eye-Hand Dominance |
Primary outcome
Dominant Eye
Time frame: 4 weeks
Eye dominance will be determined using the Miles Test. The participant will focus on a distant target with both eyes open and will then close each eye separately. The eye with which the target remains centered will be classified as the dominant eye. Eye dominance will be used with hand dominance to classify participants as having crossed or non-crossed eye-hand dominance.
Bilateral Shoulder Muscle Strength
Time frame: 4 weeks
Bilateral shoulder flexion, extension, and abduction muscle strength will be measured using a validated handheld myometer. Measurements will be recorded separately for the right and left sides. Higher force values indicate greater shoulder muscle strength, whereas lower values indicate lower muscle strength.
Bilateral Elbow Muscle Strength
Time frame: 4 weeks
Bilateral elbow flexion and extension muscle strength will be measured using a validated handheld myometer. Measurements will be recorded separately for the right and left sides. Higher force values indicate greater elbow muscle strength, whereas lower values indicate lower muscle strength.
Bilateral Handgrip Strength
Time frame: 4 weeks
Handgrip strength will be measured bilaterally using a digital hand dynamometer. Three measurements will be performed for each hand, and the mean value will be recorded. Higher values indicate greater handgrip strength, whereas lower values indicate lower handgrip strength.
Hand-Eye Coordination
Time frame: 4 weeks
Hand-eye coordination will be assessed using the Alternate-Hand Wall Toss Test. The participant will throw a ball against a wall with one hand, catch it with the opposite hand, and repeat the sequence by alternating hands. The total number of successful throws and catches completed within 30 seconds will be recorded. A higher number indicates better hand-eye coordination and motor performance, whereas a lower number indicates poorer performance.
5 secondary outcomes
Medicine Ball Throw Distance
Time frame: 4 weeks
Closed Kinetic Chain Upper Extremity Stability Test Score
Time frame: 4 weeks
Scapular Muscular Endurance Time
Time frame: 4 weeks
Upper Quarter Y-Balance Test Reach Distance
Time frame: 4 weeks
Light-Based Reaction Time
Time frame: 4 weeks
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 1 Oct 2026.
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.
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 Volleyball Player, run by Istinye University 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 7 inclusion and 5 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: looking for participants now, as of the sponsor's last update on 1 Oct 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?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Kubra Kardes, Asst. Prof. (05387115631, kubrakoce@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Dominant Eye (time frame: 4 weeks). The study lists 5 primary outcomes in all. 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 1 Oct 2026.