Eye-Hand Cross-Dominance and Upper Extremity Performance in Volleyball Players
ConditionVolleyball Player
Trial statusRecruiting
Trial phaseNot listed
Trial typeObservational
Biological sexAll
Age18-30
SponsorIstinye University
About this trial
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.
Eligibility criteria
This trial accepts healthy volunteersQualifiers
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.
Disqualifiers
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.
Trial 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.
Trial design
Design model
Case-crossover
Time perspective
Cross-sectional
Treatments tested in this trial
Volleyball Players With Crossed Eye-Hand Dominance
Other interventionVolleyball 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 Dominance
Other interventionVolleyball 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.
Treatment groups
30 Participants
are divided into 2 treatment groupsGroup A: Group 1: Volleyball Players With Crossed Eye-Hand Dominance1 intervention
Group B: Group 2: Volleyball Players Without Crossed Eye-Hand Dominance1 intervention
Trial outcomes
Primary outcomes
1
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.
Time frame
4 weeks2
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.
Time frame
4 weeks3
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.
Time frame
4 weeks4
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.
Time frame
4 weeksSecondary outcomes
1
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.
Time frame
4 weeks2
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.
Time frame
4 weeks3
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.
Time frame
4 weeks4
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.
Time frame
4 weeksSponsors and contacts
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Source ClinicalTrials.gov