Eccentric Phase Biomechanics of the Countermovement Jump After Anterior Cruciate Ligament Reconstruction (DECAL)

February 25, 2026 updated by: Forelli Florian, Haute Ecole ARC Sante

Analysis of Biomechanical Alterations During the Eccentric Phase of the Countermovement Jump in Patients After Anterior Cruciate Ligament Reconstruction

Purpose: This study aims to better understand how force is produced during a vertical jump in individuals approximately six months after anterior cruciate ligament reconstruction compared with healthy individuals. After this type of knee surgery, many patients recover well clinically but may still present strength differences between the operated and non-operated leg. These differences are not always visible during routine clinical testing but may influence performance and potentially increase the risk of reinjury. By analyzing how force is generated during a standardized countermovement jump, this study seeks to identify whether biomechanical alterations persist at this stage of recovery and to improve decision-making related to rehabilitation and return to sport.

Study Design: This is an observational comparative study. Participants who have undergone anterior cruciate ligament reconstruction using a hamstring tendon graft will be assessed between five and seven months after surgery. Their results will be compared with those of healthy recreationally active individuals without a history of recent knee injury. No experimental treatment or modification of rehabilitation will be introduced as part of this study.

Procedures: Participants will complete a brief standardized warm-up followed by three maximal vertical countermovement jumps performed on a force platform. During the test, participants will keep their hands on their hips and will be instructed to jump as quickly and as high as possible. The force platform measures ground reaction forces from each leg separately, allowing detailed analysis of the lowering phase (when the body bends before jumping) and the push-off phase (when the body propels upward). The entire testing session lasts only a few minutes and reflects movements commonly used in rehabilitation and sports settings.

Measurements: The primary measurements include jump height and the mean force produced by each leg during both the eccentric (lowering) and concentric (push-off) phases of the jump. The study will also calculate limb symmetry indices to determine the degree of difference between the operated and non-operated legs. These measurements provide objective information about neuromuscular recovery and functional performance after surgery.

Risks: The procedures involve physical activity comparable to exercises already performed during standard rehabilitation. The risks are minimal and similar to those encountered during routine physical training. Participants may stop the test at any time if they experience discomfort.

Potential Benefits: Participants may not receive direct personal benefit from taking part in the study. However, the results may contribute to improving rehabilitation strategies, refining criteria used for return-to-sport decisions, and enhancing long-term functional outcomes after anterior cruciate ligament reconstruction. A better understanding of persistent biomechanical alterations may ultimately help reduce the risk of secondary injury and optimize recovery pathways.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
100

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

Yes

Sampling Method

Probability Sample

Study Population

The study population includes adults aged 18 to 40 years. The post-anterior cruciate ligament reconstruction cohort consists of individuals who underwent primary reconstruction using a hamstring tendon autograft and are evaluated between 5 and 7 months after surgery, following completion of standard rehabilitation and medical clearance for functional testing. The healthy control cohort includes recreationally active individuals with no history of anterior cruciate ligament injury, no prior lower limb surgery, and no lower extremity injury within the past 12 months. All participants must be able to perform maximal effort jumping and isokinetic strength testing.

Description

Inclusion Criteria:

  • Post-Anterior Cruciate Ligament Reconstruction Cohort:

Age between 18 and 40 years

Primary anterior cruciate ligament reconstruction using a hamstring tendon autograft

Assessment performed between 5 and 7 months post-surgery

Completion of standard postoperative rehabilitation

Medical clearance for functional testing

Ability to perform maximal effort jumping and strength testing

Healthy Control Cohort:

Age between 18 and 40 years

Recreationally active (minimum two sessions of physical activity per week)

No history of anterior cruciate ligament injury

No lower limb surgery

No lower extremity injury within the past 12 months

No current knee pain or functional limitation

Exclusion Criteria:

  • Previous anterior cruciate ligament reconstruction on either knee (except the index surgery for the ACL group)

Concomitant ligament reconstruction (e.g., posterior cruciate ligament, medial collateral ligament, lateral collateral ligament)

Symptomatic meniscal repair limiting full participation in testing

Neurological disorders affecting lower limb function

Inflammatory joint disease

Pregnancy

Inability to perform maximal effort testing

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
ACLR
Individuals aged 18-40 years who underwent primary anterior cruciate ligament reconstruction using a hamstring tendon graft and are assessed between 5 and 7 months after surgery. Participants must have completed standard rehabilitation and be cleared for functional testing at the time of evaluation.
Other: Countermovement Jump Force Platform Assessment
Participants perform three maximal countermovement jumps on a calibrated force platform after a standardized warm-up. Hands are kept on the hips during testing. The platform records ground reaction forces from each limb separately during the eccentric (lowering) and concentric (push-off) phases of the jump. Jump height and limb symmetry indices are calculated. This procedure is used for biomechanical and functional assessment only and does not modify standard rehabilitation.
Other: Isokinetic Test
isokinetic dynamometry is performed to assess concentric quadriceps and hamstring strength at standardized angular velocities. Peak torque values and limb symmetry indices are calculated for quadriceps and hamstring
Healthy
Recreationally active individuals aged 18-40 years with no history of anterior cruciate ligament injury, no lower limb surgery, and no musculoskeletal injury affecting the lower extremities within the past 12 months. Participants must be physically active and free from current knee pain at the time of testing.
Other: Countermovement Jump Force Platform Assessment
Participants perform three maximal countermovement jumps on a calibrated force platform after a standardized warm-up. Hands are kept on the hips during testing. The platform records ground reaction forces from each limb separately during the eccentric (lowering) and concentric (push-off) phases of the jump. Jump height and limb symmetry indices are calculated. This procedure is used for biomechanical and functional assessment only and does not modify standard rehabilitation.
Other: Isokinetic Test
isokinetic dynamometry is performed to assess concentric quadriceps and hamstring strength at standardized angular velocities. Peak torque values and limb symmetry indices are calculated for quadriceps and hamstring

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Time Frame
Eccentric Mean Force
Time Frame: 3 and 6 months
3 and 6 months

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Time Frame
Concentric Mean Force
Time Frame: 3 and 6 months
3 and 6 months
Jump Height
Time Frame: 3 and 6 months
3 and 6 months
Quadriceps and Hamstring Peak Torque
Time Frame: 3 and 6 months
3 and 6 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Haute Ecole ARC Sante

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

  • Ricupito, R., Bravi, M., Santacaterina, F., Campardo, G., Guarise, R., Castellucci, R., Alaoui, I. B., & Forelli, F. (2025). Biomechanical Alterations in the Unweight Phase of the Single-Leg Countermovement Jump After ACL Reconstruction. Journal of functional morphology and kinesiology, 10(3), 296. https://doi.org/10.3390/jfmk10030296
  • Forelli, F., Moiroux-Sahraoui, A., Mazeas, J., Ly, W., Bialy, M., Douryang, M., Hewett, T. E., & De Fontenay, B. P. (2025). Evaluation of eccentric and concentric force during vertical jump after anterior cruciate ligament reconstruction: a comparative study. BMC sports science, medicine & rehabilitation, 17(1), 259. https://doi.org/10.1186/s13102-025-01301-4
  • Forelli, F., Moiroux-Sahraoui, A., Nekhouf, B., Bouzekraoui Alaoui, I., Vandebrouck, A., Duffiet, P., Ratte, L., Bialy, M., Bjerregaard, A., Mazeas, J., Douryang, M., & Rambaud, A. (2025). Is Deceleration the Key Element in Vertical Jump Performance to Return to Sport After Anterior Cruciate Ligament Reconstruction With Hamstring Graft? A Preliminary Study. International journal of sports physical therapy, 20(9), 1321-1329. https://doi.org/10.26603/001c.142878

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
March 2, 2022

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
March 31, 2025

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
March 31, 2025

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
February 25, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 25, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
March 4, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
March 4, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 25, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
March 1, 2022

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • DECAL ACL

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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