Dynamic Knee ValgusNCT07918612
Effects of Virtual Reality-Based Optokinetic Stimulation on Landing Technique and Dynamic Knee Valgus in Athletes
A study testing Drop Vertical Jump Training and Virtual Reality-Based Optokinetic Stimulation in people with Dynamic Knee Valgus and Jump-Landing Technique, run by Bahçeşehir University at 1 site in Turkey (Türkiye).
Trial summary
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. Read more about this study
- Who is it for?
- Ages 18 to 24 years
- Conditions the study is for
- Dynamic Knee Valgus, Jump-Landing Technique
- What is being tested?
- Drop Vertical Jump Training and Virtual Reality-Based Optokinetic Stimulation
- Type of treatment
- Medical device, Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 20 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- Nov 2026to Mar 2027
- Phase
- Interventional
- 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 24 years
- All sexes
- No healthy volunteers
- Adult
Who may be able to join
- 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.
Who cannot join
- 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.
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
Istanbul Nisantasi University
Istanbul
Büşra Tamgüç, 05313373355, busra.tamguc.9@gmail.com
About this study
Official title: 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.
Read the 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.
- Conditions
- Dynamic Knee Valgus, Jump-Landing Technique
- Being tested
- Drop Vertical Jump Training, Virtual Reality-Based Optokinetic Stimulation
- Keywords
- Optokinetic Stimulation, Virtual Reality, Drop Vertical Jump, Landing Error Scoring System, Frontal Plane Projection Angle
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Drop Vertical Jump TrainingBehavioural
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.
Virtual Reality-Based Optokinetic StimulationDevice
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.
| Study group | Role | What they receive |
|---|---|---|
| VR-OKS Group | Experimental | 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 Receives: Behavioral: Drop Vertical Jump Training; Device: Virtual Reality-Based Optokinetic Stimulation |
| Control Group | Active comparator | 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. Receives: Behavioral: Drop Vertical Jump Training |
What is being measured
The primary outcome is the main question the study is designed to answer.
Landing Error Scoring System (LESS) Score
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.
Measured: Baseline (before training), immediately after the training session, and one week after training (retention).
Secondary outcomes (1)
Frontal Plane Projection Angle (FPPA) During Single-Leg Squat
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.
Measured: Baseline (before training), immediately after the training session, and one week after training (retention).
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Nov 2026
- Study startNov 2026 (estimated)
- Primary completionMar 2027 (estimated)
- Study completionMar 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Dynamic Knee ValgusStudies 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
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Twenty eligible athletes will be randomly assigned in a 1:1 ratio to two parallel groups: drop vertical jump training supplemented with virtual reality-based optokinetic stimulation, or the same training without additional optokinetic stimulation. Outcomes will be assessed before training, after training, and at one-week retention.
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 20 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Bahçeşehir University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Büşra Tamgüç, Bahçeşehir University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07918612
- Sponsor's protocol ID
- SBETKK202610
- Status last verified
- Oct 2026
- First submitted
- 31 Oct 2026
- Last updated
- 5 Nov 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: 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.
Study at a glance
From the registry record, last updated by the sponsor on 5 Nov 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of Optokinetic Stimulation Added to Drop Vertical Jump Training on Landing Error Scores and Dynamic Knee Valgus: An Assessor-Blinded Randomized Controlled Trial
- ClinicalTrials.gov ID
- NCT07918612
- Acronym / sponsor ID
- SBETKK202610
- Conditions
- Dynamic Knee Valgus, Jump-Landing Technique
- Keywords
- Optokinetic Stimulation, Virtual Reality, Drop Vertical Jump, Landing Error Scoring System, Frontal Plane Projection Angle
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 20 participants (estimated)
- Lead sponsor
- Bahçeşehir UniversityUniversity, hospital or other
- Study start
- Nov 2026 (estimated)
- Primary completion
- Mar 2027 (estimated)
- Study completion
- Mar 2027 (estimated)
- First posted
- 5 Nov 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 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.
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 design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
- Model description
- Twenty eligible athletes will be randomly assigned in a 1:1 ratio to two parallel groups: drop vertical jump training supplemented with virtual reality-based optokinetic stimulation, or the same training without additional optokinetic stimulation. Outcomes will be assessed before training, after training, and at one-week retention.
| Arm | Type | Receives |
|---|---|---|
| VR-OKS Group | Experimental | Behavioral: Drop Vertical Jump Training, Device: Virtual Reality-Based Optokinetic StimulationParticipants 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 |
| Control Group | Active comparator | Behavioral: Drop Vertical Jump TrainingParticipants 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. |
Who may qualify
- Ages
- 18 to 24 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (8 listed)
- 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.
Key exclusion criteria (8 listed)
- 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.
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 |
|---|---|---|
| Drop Vertical Jump TrainingFollowing 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. | Behavioural | Control Group, VR-OKS Group |
| Virtual Reality-Based Optokinetic StimulationOptokinetic 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. | Device | VR-OKS Group |
Primary outcome
Landing Error Scoring System (LESS) Score
Time frame: Baseline (before training), immediately after the training session, and one week after training (retention).
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.
1 secondary outcome
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).
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 5 Nov 2026.
- Individual participant dataSharing planned: No. 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.
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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?
A study testing Drop Vertical Jump Training and Virtual Reality-Based Optokinetic Stimulation in people with Dynamic Knee Valgus and Jump-Landing Technique, run by Bahçeşehir 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 8 inclusion and 8 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: opening soon, as of the sponsor's last update on 5 Nov 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 Büşra Tamgüç, PT, MSc (05313373355, busra.tamguc.9@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Landing Error Scoring System (LESS) Score (time frame: Baseline (before training), immediately after the training session, and one week after training (retention).). 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 5 Nov 2026.