Effects of Virtual Reality-Based Optokinetic Stimulation on Landing Technique and Dynamic Knee Valgus in Athletes
Effects of Optokinetic Stimulation Added to Drop Vertical Jump Training on Landing Error Scores and Dynamic Knee Valgus: An Assessor-Blinded Randomized Controlled Trial
This pilot study will examine whether adding virtual reality-based optokinetic stimulation to jump-landing training changes landing technique and inward knee movement in young adult athletes. Optokinetic stimulation involves watching moving visual scenes through a virtual reality headset.
Twenty licensed basketball or volleyball athletes aged 18-24 years will be randomly assigned to two groups. Both groups will complete the same jump-landing training, consisting of two blocks of 10 repetitions with performance feedback. One group will also receive seated virtual reality-based optokinetic stimulation before each training block.
Landing technique will be assessed using the Landing Error Scoring System. Inward knee movement will be assessed by measuring the frontal plane projection angle during single-leg squats. Assessments will take place before training, after training, and one week later to determine whether any changes are retained. The assessor will not know which group each participant has been assigned to.
Study Overview
Status
Conditions
Intervention / Treatment
Detailed Description
This two-arm, parallel-group, assessor-blinded randomized controlled study will investigate the immediate and one-week retention effects of virtual reality-based optokinetic stimulation added to drop vertical jump training.
Before randomization, all candidates will complete a five-minute virtual reality familiarization session. System usability and simulator sickness symptoms will be assessed to determine eligibility. Twenty eligible athletes will be randomly allocated to jump-landing training alone or the same training supplemented with virtual reality-based optokinetic stimulation.
Both groups will complete a standardized warm-up and task familiarization, followed by baseline assessment. Training will consist of two blocks of 10 drop vertical jumps from a 30-cm box toward a target positioned at a distance equal to 50% of the participant's height. Participants will rest for 30 seconds between repetitions and five minutes between training blocks. Performance feedback based on landing errors will be provided after each block.
In the experimental group, optokinetic stimulation will be delivered using a Meta Quest 3S headset while participants sit in a supported chair with their feet on the floor. A custom virtual environment will display moving balloons against a sky background. Participants will track a red target balloon with their eyes while keeping their head as still as possible. Foreground stimuli will move at 30 degrees per second, with the background moving in the opposite direction at twice that speed. Before each training block, participants will receive three 60-second exposures in each direction, providing six minutes of active stimulation per block and 12 minutes across the session, excluding rest periods. The headset will be removed before jump training.
The primary outcome will be landing technique assessed using the Landing Error Scoring System from frontal and sagittal video recordings. The secondary outcome will be the frontal plane projection angle during single-leg squatting, calculated as the mean of three successful repetitions at the deepest squat position. Both outcomes will be assessed at baseline, after training, and at a one-week retention visit by an assessor blinded to group allocation. Post-training and retention assessments will be performed without additional corrective instructions or performance feedback.
Simulator sickness symptoms will be monitored in the virtual reality group. Stimulation will be stopped if moderate or severe symptoms occur, safe continuation is not possible, or the participant wishes to stop. The System Usability Scale will be used for eligibility screening, and the Simulator Sickness Questionnaire will be used for tolerability screening and symptom monitoring; neither will be treated as an efficacy outcome.
Study Type
Enrollment (Estimated)
Phase
- Not Applicable
Contacts and Locations
Study Contact
- Name: Büşra Tamgüç, PT, MSc
- Phone Number: 05313373355
- Email: busra.tamguc.9@gmail.com
Study Locations
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Istanbul, Turkey (Türkiye)
- Istanbul Nisantasi University
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Contact:
- Büşra Tamgüç
- Phone Number: 05313373355
- Email: busra.tamguc.9@gmail.com
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Participation Criteria
Eligibility Criteria
Ages Eligible for Study
Accepts Healthy Volunteers
Genders Eligible for Study
Description
Inclusion Criteria:
- Aged 18-24 years.
Body mass index between 18.5 and 25 kg/m².
Currently participating as an active, licensed basketball or volleyball athlete.
No trunk or lower-extremity injury within the previous six months.
Frontal plane projection angle greater than 10 degrees during the single-leg squat test.
System Usability Scale classification of A+, corresponding to the 96th-100th percentile, following virtual reality familiarization.
Ability to tolerate a five-minute virtual reality familiarization session, with a Simulator Sickness Questionnaire total score of 20 or less after the session.
Provision of written informed consent.
Exclusion Criteria:
- History of trunk or lower-extremity injury within the previous six months.
History of lower-extremity fracture or dislocation.
History of low back pain.
Musculoskeletal abnormalities.
Visual, auditory, vestibular, or neurological impairments that prevent performance of the study tasks.
Pregnancy.
Malignancy or metabolic disease.
Cybersickness symptoms that prevent toleration of the virtual reality application.
Study Plan
How is the study designed?
Design Details
- Primary Purpose: Prevention
- Allocation: Randomized
- Interventional Model: Parallel Assignment
- Masking: Single
Arms and Interventions
Participant Group / Arm |
Intervention / Treatment |
|---|---|
|
Experimental: VR-OKS Group
Participants will complete a single session of drop vertical jump training consisting of two blocks of 10 repetitions, with 30 seconds of rest between repetitions and five minutes between blocks. Performance feedback will be provided after each block. Seated virtual reality-based optokinetic stimulation will be administered before each training block, consisting of three 60-second exposures in each direction, totaling six minutes of active stimulation per block |
Following a standardized warm-up and task familiarization, participants will perform two blocks of 10 drop vertical jumps from a 30-cm box toward a target positioned at 50% of their height. After landing on both feet, participants will immediately jump as high and forward as possible and maintain the final landing position for five seconds. Rest periods will be 30 seconds between repetitions and five minutes between blocks. Feedback based on real-time landing error scores will be provided after each block. Optokinetic stimulation will be delivered through a Meta Quest 3S headset while participants sit in a supported chair with their feet on the floor. Participants will track a red balloon with their eyes while keeping their head as still as possible. Foreground stimuli will move at 30 degrees per second, with the background moving in the opposite direction at twice that speed. Three 60-second exposures will be delivered in each direction before each training block, with 30-60-second rest periods. Active stimulation will total six minutes per block and 12 minutes across the session, excluding rest. The headset will be removed before jump training. |
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Active Comparator: Control Group
Participants will complete the same single-session drop vertical jump training as the experimental group, consisting of two blocks of 10 repetitions, with 30 seconds of rest between repetitions and five minutes between blocks. Performance feedback will be provided after each block. No additional optokinetic stimulation will be administered before the training blocks. |
Following a standardized warm-up and task familiarization, participants will perform two blocks of 10 drop vertical jumps from a 30-cm box toward a target positioned at 50% of their height. After landing on both feet, participants will immediately jump as high and forward as possible and maintain the final landing position for five seconds. Rest periods will be 30 seconds between repetitions and five minutes between blocks. Feedback based on real-time landing error scores will be provided after each block. |
What is the study measuring?
Primary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
|---|---|---|
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Landing Error Scoring System (LESS) Score
Time Frame: Baseline (before training), immediately after the training session, and one week after training (retention).
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Landing technique will be assessed using the 17-item Landing Error Scoring System (LESS) from frontal and sagittal video recordings of the drop vertical jump task. Total scores range from 0 to 19 points, with higher scores indicating more landing errors and poorer landing technique. Participants will complete five successful trials at each assessment, and the mean total score across these five trials will be used for analysis. Assessments will be performed by an assessor blinded to group allocation. Changes over time will be compared between groups. |
Baseline (before training), immediately after the training session, and one week after training (retention).
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Secondary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
|---|---|---|
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Frontal Plane Projection Angle (FPPA) During Single-Leg Squat
Time Frame: Baseline (before training), immediately after the training session, and one week after training (retention).
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Dynamic knee valgus will be assessed using two-dimensional frontal-plane video analysis during a single-leg squat on the dominant limb. The frontal plane projection angle (FPPA), expressed in degrees, will be measured at the deepest squat position using lines connecting the anterior superior iliac spine, the midpoint of the patella, and the midpoint of the ankle joint. The mean of three successful repetitions will be used for analysis. Changes over time will be compared between groups by an assessor blinded to group allocation.Assessments will be performed by an assessor blinded to group allocation. Changes over time will be compared between groups. |
Baseline (before training), immediately after the training session, and one week after training (retention).
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Collaborators and Investigators
Sponsor
Study record dates
Study Major Dates
Study Start (Estimated)
Primary Completion (Estimated)
Study Completion (Estimated)
Study Registration Dates
First Submitted
First Submitted That Met QC Criteria
First Posted (Actual)
Study Record Updates
Last Update Posted (Actual)
Last Update Submitted That Met QC Criteria
Last Verified
More Information
Terms related to this study
Keywords
Other Study ID Numbers
- SBETKK202610
Plan for Individual participant data (IPD)
Plan to Share Individual Participant Data (IPD)?
IPD Plan Description
Individual participant data will not be shared with researchers outside the study team, in accordance with the confidentiality provisions of the approved study protocol and informed consent form. Study findings will be reported in aggregate form through scientific publications and presentations.
Drug and device information, study documents
Studies a U.S. FDA-regulated drug product
Studies a U.S. FDA-regulated device product
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