ACL ReconstructionRTP-VJNCT07297511
Application of Multiple Vertical Jump Tests in Return-to-Play Assessment for Anterior Cruciate Ligament Reconstruction Athletes
An observational study of ACL Reconstruction, run by Kaohsiung Medical University at 1 site in Taiwan.
Trial summary
Anterior cruciate ligament (ACL) injury is a common sports-related injury, particularly in sports that require extensive jumping and cutting movements. Although anterior cruciate ligament reconstruction (ACLR) surgery can restore knee stability, many athletes still face the risk of re-injury after returning to… Read more about this study
- Who is it for?
- Ages 18 to 35 yearsHealthy volunteers can take part
- Conditions the study is for
- ACL Reconstruction
- How many people
- 36 participants
- Where
- 1 siteTaiwan
- Study dates
- 29 Dec 2025to 30 Jan 2026
- How long will I take part?
- 1 Day
- 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 35 years
- All sexes
- Healthy volunteers accepted
- Adult
Study population: The study population consists of two distinct groups: (1) ACLR athletes: elite athletes aged 18-35 years who have undergone unilateral anterior cruciate ligament reconstruction using hamstring or gracilis autograft with a minimum of 6 months post-operative. These participants will be recruited from orthopedic clinics, sports medicine centers, and rehabilitation facilities in the region. (2) Healthy controls: age, sex, and athletic-level matched individuals aged 18-35 years with no history of lower extremity injuries, recruited from local athletic facilities, university sports programs, and community sports organizations. Both groups must have elite athlete status, defined as prior participation in national-level sports competitions. The ACLR group represents athletes in the late rehabilitation phase preparing for return-to-play, while the healthy control group serves as a reference for normal biomechanical performance.
Who may be able to join
- 1.Age 18-35 years
- 2.Unilateral anterior cruciate ligament (ACL) rupture confirmed by magnetic resonance imaging (MRI)
- 3.Positive Lachman test grade ≥2 pre-operatively
- 4.Anterior cruciate ligament reconstruction (ACLR) using hamstring or gracilis autograft
- 5.Post-operative time ≥6 months
- 6.Completed rehabilitation program with clearance from orthopedic surgeon or physical therapist
- 7.Quadriceps strength symmetry index ≥90%
- .Elite athlete status (prior participation in national-level competitions)
Who cannot join
- Other lower extremity injuries or pathologies (including other knee ligament injuries)
- Contralateral lower limb injury within the past 3 months
- Quadriceps strength symmetry index <90%
- Non-elite athlete status (no prior national-level competition participation)
- Incomplete rehabilitation or lack of medical clearance
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Taiwan1 site
Kaohsiung Medical University
Kaohsiung City
Teng C Y Undergraduate student of Sports Medicine, Bachelor's degree, +886-958-392-604, a266422a@gmail.com
Guo L Y Professor and Dean of the College of Health Sciences, Doctorate, +8867-3121101 ext. #2646 #614, yuen@kmu.edu.tw
About this study
Official title: The Application of Vertical Jump Performance in Return-to-Play Assessment for Anterior Cruciate Ligament Reconstruction Athletes
Anterior cruciate ligament (ACL) injury is a common sports-related injury, particularly in sports that require extensive jumping and cutting movements. Although anterior cruciate ligament reconstruction (ACLR) surgery can restore knee stability, many athletes still face the risk of re-injury after returning to competition.Current return-to-play assessment relies primarily on single-plane horizontal hop tests and symmetry indices (LSI ≥ 90%); however, an increasing body of research suggests that these tests may not comprehensively reflect functional deficits in the vertical plane, repeated hopping, or high-intensity sport-specific activities.This study hypothesizes that incorporating multiple vertical jump tests-including single-leg vertical jumps and 10-second repeated vertical jumps-combined with advanced force plate analytics (such as Reactive Strength Index [RSI] and Time to Stabilization [TTS])-can more sensitively reveal residual neuromuscular control deficits following surgery. This approach would provide evidence-based guidance for return-to-play decision-making, thereby improving athletes' long-term athletic performance and safety.
Read the detailed description
This cross-sectional study compares biomechanical performance between ACLR athletes (>6 months post-op) and healthy controls to evaluate whether vertical jump protocols reveal greater limb asymmetries compared to traditional horizontal hop tests. Following a 5-minute stationary bicycle warm-up and familiarization trials, participants perform four unilateral tasks on both limbs: Single-Legged Hop for Distance (SHD), Crossover Hop for Distance (CHD), Single-Legged Vertical Countermovement Jump (SLVJ), and 10-Second Repeated Single-Legged Vertical Jump (SLVJs). All tasks are performed with hands on hips to minimize compensatory motion. Three successful trials are recorded per limb per task with 3-minute rest intervals between sets. Trials are discarded if participants land on the contralateral limb, lose balance, or fail to land on the force plate. Vertical ground reaction forces are collected using a dual-force plate system (Hawkin Dynamics, 3rd Generation) at 1000 Hz. Data processing calculates Limb Symmetry Index (LSI), Modified Reactive Strength Index (RSI) from SLVJs as Jump Height divided by Movement Time, Time to Stabilization (TTS) defined as the duration for vGRF to stabilize within ±5% of body weight, and eccentric/concentric impulse.
- Conditions
- ACL Reconstruction
- Keywords
- ACL reconstruction, vertical jump test, return to play
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Health: Control group | The group include athletes with no lower limbs injury.Participants must be aged 18-35 years and must be elite athletes who have competed in national-level competitions. | |
| ACL reconstruction | Participants must be aged 18-35 years with unilateral ACL rupture confirmed by MRI, Lachman test grade ≥2, and reconstruction using hamstring or gracilis autograft with at least 6 months post-operative. Participants must have completed rehabilitation with clearance from an orthopedic surgeon or physical therapist, demonstrate no other lower extremity injuries, and have no contralateral lower limb injury within the past 3 months. Additionally, quadriceps strength symmetry index must be ≥90%, and participants must be elite athletes who have competed in national-level competitions. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Limb asymmetry index,LSI
Limb Symmetry Index (LSI) calculated as (|Uninvolved limb value - Involved limb value| / (Uninvolved limb value + Involved limb value)) × 100% for each of the four jump tasks: Single-Legged Hop for Distance (SHD), Crossover Hop for Distance (CHD), Single-Legged Vertical Countermovement Jump (SLVJ), and 10-Second Repeated Single-Legged Vertical Jump (SLVJs). LSI values will be compared between ACLR athletes and healthy controls to determine whether vertical jump protocols reveal greater limb asymmetries than traditional horizontal hop tests. Primary analysis will examine whether LSI differences in vertical jump tasks are statistically significantly lower (indicating greater asymmetry) than horizontal hop tasks, revealing residual neuromuscular deficits not detected by conventional return-to-play assessment.
Measured: At baseline (single testing session; no longitudinal follow-up)
Secondary outcomes (5)
Modified Reactive Strength Index
Modified Reactive Strength Index (mRSI) calculated as Flight Time(s) divided by Time to Take-off(s) for the 10-Second Repeated Single-Legged Vertical Jump (SLVJs) task.
Measured: At baseline (single testing session; no longitudinal follow-up)
Time to Stabilization (seconds)
Time to Stabilization (TTS) measured during the Single-Legged Vertical Countermovement Jump (SLVJ) task, defined as the time required for vertical ground reaction force (vGRF) to return to and stabilize within ±5% of the participant's body weight following landing.
Measured: At baseline (single testing session; no longitudinal follow-up)
Single-Legged Hop for Distance (centimeter)
Single-Legged Hop for Distance (SHD) measured as the maximum horizontal distance(centimeter) achieved during a single maximal hop on the tested leg, performed bilaterally.
Measured: At baseline (single testing session; no longitudinal follow-up)
Crossover Hop for Distance (centimeter)
Crossover Hop for Distance (CHD) measured as the total horizontal distance covered during three consecutive hops crossing a centerline, performed bilaterally with emphasis on stability and continuity.
Measured: At baseline (single testing session; no longitudinal follow-up)
Jump Height(meter)
Jump Height measured during the Single-Legged Vertical Countermovement Jump (SLVJ) and 10-Second Repeated Single-Legged Vertical Jump (SLVJs) tasks, calculated from the flight time (time from takeoff to landing) using force plate data.
Measured: At baseline (single testing session; no longitudinal follow-up)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 Dec 2025
- Study start29 Dec 2025 (estimated)
- Primary completion30 Jan 2026 (estimated)
- Study completion30 Jan 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for ACL ReconstructionStudies 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-control
- Time perspective
- Cross-sectional
- Enrolment
- 36 participants (estimated)
- Target duration
- 1 Day
Sponsor and investigators
- Lead sponsor
- Kaohsiung Medical University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Cheng-Yen Teng, Kaohsiung Medical University
- Investigators
- GUO L Y Professor and Dean of college, Ph.D., Study chair, Department of Sports Science, Kaohsiung Medical University, Taiwan
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07297511
- Sponsor's protocol ID
- KMUHIRB-F(II)-202 20046
- Other IDs
- KMUHIRB-F(II)-202 20046
- Acronym
- RTP-VJ
- Status last verified
- Jul 2025
- First submitted
- 9 Dec 2025
- Last updated
- 22 Dec 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: De-identified individual participant data (IPD) that underlie the main published results, including demographic characteristics and biomechanical outcome measures (e.g., jump height, limb symmetry index, RSI, TTS, and impulse), will be shared with qualified researchers upon reasonable request, after approval of a data use agreement and in accordance with applicable ethical and regulatory requirements.
Study at a glance
From the registry record, last updated by the sponsor on 22 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Application of Vertical Jump Performance in Return-to-Play Assessment for Anterior Cruciate Ligament Reconstruction Athletes
- ClinicalTrials.gov ID
- NCT07297511
- Acronym / sponsor ID
- RTP-VJ / KMUHIRB-F(II)-202 20046
- Conditions
- ACL Reconstruction
- Keywords
- ACL reconstruction, vertical jump test, return to play
- Study type
- Observational
- Recruitment status
- Not yet recruiting
- Enrolment
- 36 participants (estimated)
- Lead sponsor
- Kaohsiung Medical UniversityUniversity, hospital or other
- Study start
- 29 Dec 2025 (estimated)
- Primary completion
- 30 Jan 2026 (estimated)
- Study completion
- 30 Jan 2026 (estimated)
- First posted
- 22 Dec 2025 (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.
Anterior cruciate ligament (ACL) injury is a common sports-related injury, particularly in sports that require extensive jumping and cutting movements. Although anterior cruciate ligament reconstruction (ACLR) surgery can restore knee stability, many athletes still face the risk of re-injury after returning to competition.Current return-to-play assessment relies primarily on single-plane horizontal hop tests and symmetry indices (LSI ≥ 90%); however, an increasing body of research suggests that these tests may not comprehensively reflect functional deficits in the vertical plane, repeated hopping, or high-intensity sport-specific activities.This study hypothesizes that incorporating multiple vertical jump tests-including single-leg vertical jumps and 10-second repeated vertical jumps-combined with advanced force plate analytics (such as Reactive Strength Index [RSI] and Time to Stabilization [TTS])-can more sensitively reveal residual neuromuscular control deficits following surgery. This approach would provide evidence-based guidance for return-to-play decision-making, thereby improving athletes' long-term athletic performance and safety.
Detailed description
This cross-sectional study compares biomechanical performance between ACLR athletes (>6 months post-op) and healthy controls to evaluate whether vertical jump protocols reveal greater limb asymmetries compared to traditional horizontal hop tests. Following a 5-minute stationary bicycle warm-up and familiarization trials, participants perform four unilateral tasks on both limbs: Single-Legged Hop for Distance (SHD), Crossover Hop for Distance (CHD), Single-Legged Vertical Countermovement Jump (SLVJ), and 10-Second Repeated Single-Legged Vertical Jump (SLVJs). All tasks are performed with hands on hips to minimize compensatory motion. Three successful trials are recorded per limb per task with 3-minute rest intervals between sets. Trials are discarded if participants land on the contralateral limb, lose balance, or fail to land on the force plate. Vertical ground reaction forces are collected using a dual-force plate system (Hawkin Dynamics, 3rd Generation) at 1000 Hz. Data processing calculates Limb Symmetry Index (LSI), Modified Reactive Strength Index (RSI) from SLVJs as Jump Height divided by Movement Time, Time to Stabilization (TTS) defined as the duration for vGRF to stabilize within ±5% of body weight, and eccentric/concentric impulse.
Study design
- Observational model
- Case-control
- Time perspective
- Cross-sectional
- Target follow-up
- 1 Day
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Health: Control group | – | –The group include athletes with no lower limbs injury.Participants must be aged 18-35 years and must be elite athletes who have competed in national-level competitions. |
| ACL reconstruction | – | –Participants must be aged 18-35 years with unilateral ACL rupture confirmed by MRI, Lachman test grade ≥2, and reconstruction using hamstring or gracilis autograft with at least 6 months post-operative. Participants must have completed rehabilitation with clearance from an orthopedic surgeon or physical therapist, demonstrate no other lower extremity injuries, and have no contralateral lower limb injury within the past 3 months. Additionally, quadriceps strength symmetry index must be ≥90%, and participants must be elite athletes who have competed in national-level competitions. |
Who may qualify
- Ages
- 18 to 35 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
- Study population
- The study population consists of two distinct groups: (1) ACLR athletes: elite athletes aged 18-35 years who have undergone unilateral anterior cruciate ligament reconstruction using hamstring or gracilis autograft with a minimum of 6 months post-operative. These participants will be recruited from orthopedic clinics, sports medicine centers, and rehabilitation facilities in the region. (2) Healthy controls: age, sex, and athletic-level matched individuals aged 18-35 years with no history of lower extremity injuries, recruited from local athletic facilities, university sports programs, and community sports organizations. Both groups must have elite athlete status, defined as prior participation in national-level sports competitions. The ACLR group represents athletes in the late rehabilitation phase preparing for return-to-play, while the healthy control group serves as a reference for normal biomechanical performance.
Key inclusion criteria (8 listed)
- 1.Age 18-35 years
- 2.Unilateral anterior cruciate ligament (ACL) rupture confirmed by magnetic resonance imaging (MRI)
- 3.Positive Lachman test grade ≥2 pre-operatively
- 4.Anterior cruciate ligament reconstruction (ACLR) using hamstring or gracilis autograft
- 5.Post-operative time ≥6 months
Key exclusion criteria (5 listed)
- Other lower extremity injuries or pathologies (including other knee ligament injuries)
- Contralateral lower limb injury within the past 3 months
- Quadriceps strength symmetry index <90%
- Non-elite athlete status (no prior national-level competition participation)
- Incomplete rehabilitation or lack of medical clearance
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Limb asymmetry index,LSI
Time frame: At baseline (single testing session; no longitudinal follow-up)
Limb Symmetry Index (LSI) calculated as (|Uninvolved limb value - Involved limb value| / (Uninvolved limb value + Involved limb value)) × 100% for each of the four jump tasks: Single-Legged Hop for Distance (SHD), Crossover Hop for Distance (CHD), Single-Legged Vertical Countermovement Jump (SLVJ), and 10-Second Repeated Single-Legged Vertical Jump (SLVJs). LSI values will be compared between ACLR athletes and healthy controls to determine whether vertical jump protocols reveal greater limb asymmetries than traditional horizontal hop tests. Primary analysis will examine whether LSI differences in vertical jump tasks are statistically significantly lower (indicating greater asymmetry) than horizontal hop tasks, revealing residual neuromuscular deficits not detected by conventional return-to-play assessment.
5 secondary outcomes
Modified Reactive Strength Index
Time frame: At baseline (single testing session; no longitudinal follow-up)
Time to Stabilization (seconds)
Time frame: At baseline (single testing session; no longitudinal follow-up)
Single-Legged Hop for Distance (centimeter)
Time frame: At baseline (single testing session; no longitudinal follow-up)
Crossover Hop for Distance (centimeter)
Time frame: At baseline (single testing session; no longitudinal follow-up)
Jump Height(meter)
Time frame: At baseline (single testing session; no longitudinal follow-up)
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 22 Dec 2025.
- Individual participant dataSharing planned: Yes. De-identified individual participant data (IPD) that underlie the main published results, including demographic characteristics and biomechanical outcome measures (e.g., jump height, limb symmetry index, RSI, TTS, and impulse), will be shared with qualified researchers upon reasonable request, after approval of a data use agreement and in accordance with applicable ethical and regulatory requirements.
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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.
GUO L Y Professor and Dean of college, Ph.D. study chair
Department of Sports Science, Kaohsiung Medical University, Taiwan
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 ACL Reconstruction, run by Kaohsiung Medical University at 1 site in Taiwan.
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 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: opening soon, as of the sponsor's last update on 22 Dec 2025. 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 Taiwan. 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 Teng C Y Kaohsiung Medical University, Bachelor (+886-958-392-604, a266422a@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Limb asymmetry index,LSI (time frame: At baseline (single testing session; no longitudinal follow-up)). 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 22 Dec 2025.