Eye-Hand Cross-Dominance and Upper Extremity Performance in Volleyball Players

NCT07784530 | Recruiting

• 1 other identifier: 2026/01
• Study Type: observational
• Target: 30
• Locations: 1 country
• Sites: 1

Brief 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. 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

Keywords

Eye-Hand Dominance; Volleyball Players; Upper Extremity Performance

Outcome Measures

Primary Outcomes (5)

• 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.

  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.

  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.

  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.

  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.

  4 weeks

Secondary Outcomes (5)

• Medicine Ball Throw Distance

  4 weeks

• Closed Kinetic Chain Upper Extremity Stability Test Score

  4 weeks

• Scapular Muscular Endurance Time

  4 weeks

• Upper Quarter Y-Balance Test Reach Distance

  4 weeks

• Light-Based Reaction Time

  4 weeks

Study Arms (2)

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

Interventions

Volleyball Players With Crossed Eye-Hand Dominance OTHER

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.

Group 1: Volleyball Players With Crossed Eye-Hand Dominance

Volleyball Players Without Crossed Eye-Hand Dominance OTHER

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.

Group 2: Volleyball Players Without Crossed Eye-Hand Dominance

Eligibility Criteria

• Age: 18 Years - 30 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)
• Sampling Method: Probability Sample

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.

You may qualify if:

• 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.

You may not qualify if:

• 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.

Sponsors & Collaborators

• Istinye University: lead

Study Sites (1)

Istinye University

Istanbul, 34010, Turkey (Türkiye)

RECRUITING

Central Study Contacts

Kubra Kardes, Asst. Prof.

CONTACT

05387115631; kubrakoce@gmail.com

Study Design

• Study Type: observational
• Observational Model: CASE CROSSOVER
• Time Perspective: CROSS SECTIONAL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Asst. Prof.

Study Record Dates

• First Submitted: August 21, 2026
• First Posted: August 25, 2026
• Study Start: August 30, 2026
• Primary Completion (Estimated): November 15, 2026
• Study Completion (Estimated): November 30, 2026
• Last Updated: October 1, 2026

Record last verified: 2026-09

Locations

TU (1)