Bilateral Lower Limb Biomechanics During Side-Cutting in Unilateral Patellar Tendinopathy

March 8, 2026 updated by: Peking University Third Hospital

Comparison of Bilateral Lower Limb Biomechanics During Side-Cutting Between Patients With Unilateral Patellar Tendinopathy and Healthy Controls

Patellar tendinopathy (PT) is a common overuse injury in sports that involve jumping and directional changes. The biomechanical differences between individuals with PT and healthy controls during side-cutting, as well as whether both legs are similarly affected, remain unclear. This study aimed to compare the kinematics and kinetics of the affected leg in patients with PT, their unaffected leg, and healthy controls during side-cutting. Methods: Thirty patients with PT and thirty healthy participants performed a side-cutting task. Motion capture and force plates were used to collect data. Five peak ground reaction forces (GRFs) and the corresponding hip, knee, and ankle joint angles and moments were analyzed. Statistical comparisons were performed using t-tests with Bonferroni correction.

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.

Detailed Description

Patellar tendinopathy (PT) is a musculoskeletal disorder characterized by localized pain at the junction of the inferior pole of the patella and the patellar tendon insertion. It is considered an overuse injury, predominantly affecting highly active populations participating in sports that involve repetitive jumping, running, and side-cutting, such as volleyball, soccer, and basketball, where the patellar tendon repeatedly stores and releases energy. The long-term accumulation of mechanical load in these activities can lead to structural changes in the tendon. Current biomechanical research on patellar tendinopathy has primarily focused on jumping tasks. Previous studies suggest that individuals with PT tend to adopt a pain-avoidance strategy by reducing knee flexion during landing to decrease patellar tendon loading, and they also demonstrate significantly reduced knee extension moments and rates of moment development at initial contact. However, some studies have found no significant differences in knee flexion angle or extension moment compared to healthy controls, yet these individuals still exhibit increased local patellar tendon stress, indicating that patellar tendon loading may be triplanar and should not be analyzed solely in the sagittal plane, highlighting the importance of also considering the frontal and transverse planes. Notably, research using individualized finite element models has systematically quantified the effects of femoral and tibial rotations in the frontal and horizontal planes on peak principal stress in the patellar tendon, showing that rotation in the horizontal plane has a significant impact on tendon stress. Since the hip joint serves as the proximal driver of femoral horizontal rotation, hip motion in the horizontal plane warrants particular attention. However, biomechanical studies examining hip, knee, and ankle joint mechanics in the horizontal plane in individuals with PT remain scarce. The side-cutting maneuver is a complex task involving single-leg landing, change of direction, and push-off, during which the lower limb experiences multi-directional impact forces from the sagittal, frontal, and horizontal planes. Research on side-cutting has primarily focused on acute injuries, such as anterior cruciate ligament rupture, with limited attention to chronic conditions like PT. Existing evidence not only confirms that side-cutting increases patellar tendon loading but also suggests that individuals with anterior knee pain may be at greater risk of injury during side-cutting, emphasizing the need for biomechanical studies of side-cutting in PT populations. A proposed framework divides the side-cutting maneuver into three phases: the initial contact-deceleration phase, the stance pivot phase, and the push-off phase, which are defined by five peak ground reaction force events, including four horizontal and one vertical peak. Previous research indicates that multi-planar loading tasks, particularly horizontal landing phases, are more sensitive than vertical landing tasks in detecting aberrant biomechanical patterns in individuals with PT. Although ground reaction forces do not directly represent patellar tendon loading, they reflect the external horizontal and vertical loads experienced by the lower limb. Therefore, using a ground reaction force-based phase analysis framework for side-cutting is particularly valuable in examining vertical and horizontal movement strategies in individuals with PT. Based on this framework, the present study aims to assess, during side-cutting, the magnitudes of each peak ground reaction force and the corresponding three-dimensional joint angles and moments of the knee, hip, and ankle in the affected limb of individuals with PT, their unaffected limb, and healthy controls.

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.
60

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

  • China
    • Beijing Municipality
      • Beijing, Beijing Municipality, China
        • Beijing Key Laboratory of Research and Translation for Drugs and Medical Devices in Precision Diagnosis and Treatment of Sports

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

Non-Probability Sample

Study Population

Patients with PT were recruited from the outpatient clinic of Peking University Third Hospital and via hospital posters, whereas healthy controls were recruited through posters targeting healthy individuals. All participants read and signed the approved informed consent form before data collection.

Description

Inclusion criteria for the PT group were as follows:

  • Age 18-40 years and regular participation in sports, defined as engaging in physical activities for at least 90 minutes per week over the past three months, such as basketball, soccer, tennis, volleyball, long-distance running, and other sports activities,
  • Structural tendon changes on imaging, including tendon thickening, hypoechogenicity, and/or increased neovascularization on Doppler ultrasound, or increased signal intensity on T2-weighted Magnetic Resonance Imaging (MRI) sequences relative to normal tendon tissue, with observable localized edema, inflammation, or degenerative changes,
  • positive tenderness response upon palpation of the patellar tendon,
  • reproduction of patellar tendon pain during resisted knee extension and/or during a standardized single-leg squat test,
  • a score of ≤ 80 on the VISA-P (Victorian Institute of Sport Assessment-Patella) questionnaire.

Inclusion criteria for the control group were as follows:

  • Participants were reported regular participation in sports, defined as engaging in physical activities for at least 90 minutes per week over the past three months, such as basketball, soccer, tennis, volleyball, long-distance running, and other sports activities,
  • no history of knee injury,
  • no history of lower-limb surgery,
  • normal range of motion of the lower-limb joints (hip, knee, and ankle joints with no limitations in active or passive movements, within the normal physiological range),
  • no history of chronic joint disorders, including current or pre-existing knee pain, PT, or functional impairment
  • no evidence of patellar tendon pathology on ultrasound or MRI.

Exclusion criteria for both groups were as follows:

  • a history of trauma to other lower limb joints,
  • a history of surgery on any lower limb joint,
  • use of analgesic medication in the past two weeks,
  • the presence of other lower limb pathologies.

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.
control group
healthy individuals
Experimental group
patients with patellar tendinopathy

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
Measure Description
Time Frame
Vicon 3D gait test
Time Frame: Day 1 (single time point)
All subjects wore athletic shorts, fully exposing the waist and the area below the mid-thigh. After reflective markers were attached, participants familiarized themselves with the movement collection requirements and procedures according to the testing protocol. At the start of the formal test, participants began the approach run as soon as they heard the command "Start." They sprinted at maximal speed, accurately planting the tested leg on the second force plate, after which the contralateral leg stepped at an angle of approximately 45°. A one-minute rest interval was provided between trials, and participants were confirmed to be free of any obvious signs of fatigue or discomfort before each test. No pain was elicited throughout the testing session. Each participant completed three successful trials for each lower limb, defined as trials completed according to the experimental requirements within the prescribed time, from which complete kinematic and kinetic data were collected.
Day 1 (single time point)

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
Measure Description
Time Frame
Visual Analogue Scale for Pain and VISA-P Scale
Time Frame: Day 1 (single time point)
Visual Analogue Scale for Pain：The VAS scale is usually a horizontal or vertical line 10 cm long with "0" and "10" marked on both ends. "0" represents "no pain" and "10" represents "worst possible pain." VISA-P Scale：A patellar tendinopathy rating scale is a reliable indicator of severity and pain. The VISA-P scale covers three areas: symptoms, function, and mobility. It consists of eight questions with a maximum score of 100. The theoretical minimum score is 0, and higher scores indicate less severe pain.
Day 1 (single time point)
Surface electromyography signal parameters
Time Frame: Day 1 (single time point)
During the side-cutting tests in both participant groups, a Delsys wireless surface electromyography (sEMG) system was used to simultaneously monitor the EMG activity of the quadriceps, hamstrings, and gluteus medius muscles.
Day 1 (single time point)

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.
Peking University Third Hospital

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.
July 15, 2023

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.
May 30, 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.
May 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).
March 1, 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.
March 8, 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 11, 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 11, 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.
March 8, 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.
July 1, 2023

More Information

Terms related to this study

Keywords

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.
  • M20260228

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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