Optimizing Movement After Anterior Cruciate Ligament Injury

Fifty percent of teenagers and young adults who suffer an anterior cruciate ligament (ACL) injury develop knee osteoarthritis (OA) within 15 years. The resulting pain, reduced quality-of-life, and increased risk for co-morbidity lead to substantial healthcare costs, inability to fulfill work and personal responsibilities, and reduced long-term health. Degeneration in articular cartilage, connective tissue that covers the ends of bones in the knee, is the hallmark of early OA development after knee injury. This deterioration can be measured by an imaging biomarker for OA development on quantitative magnetic resonance imaging (MRI). Harmful increases in MRI markers of the knee's articular cartilage occur within months of ACL injury and indicate preventative interventions should begin soon after injury. However, evidence-based interventions to prevent OA do not exist.

This project will challenge the traditional OA paradigm that too much joint loading (e.g. "wear and tear") causes cartilage breakdown. A multi-disciplinary team has developed a novel visual biofeedback paradigm using portable force plates that can increase knee loading during squats within a single session after ACL reconstruction (ACLR). This study will determine the efficacy of the visual biofeedback program initiated two weeks after ACLR by assessing movement biomechanics and MRI changes in cartilage after six months later. Successful completion of this project will establish the first rehabilitation intervention to effectively and optimally load the knee joint early after ACLR, providing the initial steps to prevent OA after ACL injury.

Study Overview

• Status: Completed
• Conditions: Knee Osteoarthritis; Anterior Cruciate Ligament Injuries
• Intervention / Treatment: Procedure: Squat Biofeedback; Procedure: Standard Care

Detailed Description

Fifty percent of teenagers and young adults who suffer an anterior cruciate ligament (ACL) injury develop radiographic knee osteoarthritis (OA) within 15 years. The resulting pain, reduced quality-of-life, and increased risk for co-morbidity lead to substantial healthcare costs, inability to fulfill work and personal responsibilities, and reduced long-term health. Degeneration in articular cartilage, connective tissue that covers the ends of bones in the knee, is the hallmark of early OA development after knee injury. This deterioration can be measured by increased T2 and T1rho relaxation time on quantitative magnetic resonance imaging (MRI), an imaging biomarker for OA development. Harmful increases in MRI markers of the knee's articular cartilage occur within months of ACL injury and indicate preventative interventions should begin soon after injury. However, evidence-based interventions to prevent OA do not exist. The investigators have shown that after ACL reconstruction (ACLR), patients exhibit asymmetric movement patterns characterized by up to 62% lower knee joint loading during walking and squatting in the injured limb at two months after ACLR. These knee joint loading patterns remain 40% lower at six months. Emerging evidence suggests knee joint unloading patterns after ACL injury may increase the risk for OA development. Currently, no studies have examined the efficacy of movement-focused interventions during the first months after ACLR, which explains the lack of evidence-based interventions that successfully increase knee loading early after ACLR. This gap presents a barrier to the long-term goal of preventing OA in young, active individuals before irreversible knee degeneration occurs. This project will challenge the traditional OA paradigm that too much joint loading (e.g. "wear and tear") causes cartilage breakdown. The multi-disciplinary team spanning rehabilitation, orthopaedics, radiology and biomechanics has developed a novel visual biofeedback paradigm using portable force plates that can increase knee loading during squats within a single session after ACLR. This data suggest movement is modifiable using visual feedback, but its efficacy beyond a single training session is unknown. This study will determine the efficacy of the visual biofeedback program initiated two weeks after ACLR by assessing movement biomechanics and MRI changes in cartilage microstructure six months later. Successful completion of this project will establish the first rehabilitation intervention to effectively and optimally load the knee joint early after ACLR, providing the initial steps in the team's work to prevent OA after ACL injury.

• Study Type: Interventional
• Enrollment (Actual): 34
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Nebraska
    • Omaha, Nebraska, United States, 68198
      • University of Nebraska Medical Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 13 years to 35 years (Child, Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Acute anterior cruciate ligament (ACL) injury in the past 6 months
• ACL reconstruction in the past month or have a planned ACL reconstruction

Exclusion Criteria:

• Previous knee injury or surgery (contralateral knee)
• Body mass index (BMI) over 35 kg/m2
• Concomitant posterior cruciate ligament reconstruction or cartilage procedure that includes extended weight bearing restrictions and/or changes to cartilage structure
• Current or planned pregnancy during study duratuiom

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Control; Standard care	Procedure: Standard Care; The intervention group will receive standard care post-operative physical therapy.
Experimental: Experimental; Squat biofeedback intervention	Procedure: Squat Biofeedback; The intervention group will complete bilateral squats with each limb on a separate portable force plate. They will receive real-time visual feedback on a 32-inch screen during all squats. Biofeedback conditions will be progressed from simplest (ground reaction force only) to most complex (ground reaction force plus center of pressure). This intervention will be included in additional to standard care post-operative physical therapy.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Knee Flexion Moment Impulse	Participants completed 3 sets of 5 bilateral bodyweight squats with arms crossed at the chest, with the middle 3 of each set (9 total) averaged and reported. The external knee flexion moment was calculated using an inverse dynamics approach. The interlimb ratio (injured limb / uninjured limb) of the knee flexion moment impulse during descent and ascent of bilateral squatting was analyzed at post-intervention. A value of 1 represents symmetric knee flexion moment impulse; a value less than 1 represents a smaller knee flexion moment impulse in the injured compared to uninjured limb.	Immediately post-intervention (within approximately 1 week after completing intervention)
Cartilage T2 Relaxation Time	Percent change in cartilage T2 relaxation time will be measured by a magnetic resonance imaging (MRI) scan. A positive percent change represents longer (worse) T2 relaxation times at 6 months compared to baseline testing. The cartilage region reported is the weightbearing area of the medial femoral condyle.	Baseline (immediately before intervention, 2-6 weeks after anterior cruciate ligament reconstruction) and 6 months after anterior cruciate ligament reconstruction.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Knee Flexion Moment Impulse	Participants completed 3 sets of 5 bilateral bodyweight squats with arms crossed at the chest, with the middle 3 of each set (9 total) averaged and reported. The external knee flexion moment was calculated using an inverse dynamics approach. The interlimb ratio (injured limb / uninjured limb) of the knee flexion moment impulse during descent and ascent of bilateral squatting was analyzed at 6 months. A value of 1 represents symmetric knee flexion moment impulse; a value less than 1 represents a smaller knee flexion moment impulse in the injured compared to uninjured limb.	6 months after anterior cruciate ligament reconstruction.
Vertical Ground Reaction Force Impulse	Participants completed 3 sets of 5 bilateral bodyweight squats with arms crossed at the chest, with the middle 3 of each set (9 total) averaged and reported. The vertical ground reaction force impulse was calculated. The interlimb ratio (injured limb / uninjured limb) of the vertical ground reaction force impulse during descent and ascent of bilateral squatting was analyzed at post-intervention. A value of 1 represents symmetric vertical ground reaction force impulse; a value less than 1 represents a smaller vertical ground reaction force impulse in the injured compared to uninjured limb.	Immediately post-intervention (approximately 1 week after intervention)
Vertical Ground Reaction Force Impulse	Participants completed 3 sets of 5 bilateral bodyweight squats with arms crossed at the chest, with the middle 3 of each set (9 total) averaged and reported. The vertical ground reaction force impulse was calculated. The interlimb ratio (injured limb / uninjured limb) of the vertical ground reaction force impulse during descent and ascent of bilateral squatting was analyzed at 6 months. A value of 1 represents symmetric vertical ground reaction force impulse; a value less than 1 represents a smaller vertical ground reaction force impulse in the injured compared to uninjured limb.	6 months after anterior cruciate ligament reconstruction.
Peak Knee Flexion Moment	Participants completed 5 valid trials of walking in each limb. The external knee flexion moment was calculated using an inverse dynamics approach. The interlimb ratio (injured limb / uninjured limb) of the peak knee flexion moment during walking was analyzed at post-intervention. A value of 1 represents symmetric peak knee flexion moment; a value less than 1 represents a smaller peak knee flexion moment in the injured compared to uninjured limb.	Immediately post-intervention (within approximately 1 week after completing intervention)
Peak Knee Flexion Moment	Participants completed 5 valid trials of walking in each limb. The external knee flexion moment was calculated using an inverse dynamics approach. The interlimb ratio (injured limb / uninjured limb) of the peak knee flexion moment during walking was analyzed at 6 months. A value of 1 represents symmetric peak knee flexion moment; a value less than 1 represents a smaller peak knee flexion moment in the injured compared to uninjured limb.	6 months after anterior cruciate ligament reconstruction.
Quadriceps Strength	Participants completed 3 trials of maximal isometric quadriceps strength testing using an isokinetic dynamometer at each limb, with the best trial in each limb used for analysis. The interlimb ratio (injured limb / uninjured limb) of maximum quadriceps strength was analyzed at post-intervention. A value of 1 represents symmetric quadriceps strength; a value less than 1 represents less quadriceps strength in the injured compared to uninjured limb.	Immediately post-intervention (within approximately 1 week after completing intervention)
Quadriceps Strength	Participants completed 3 trials of maximal isometric quadriceps strength testing using an isokinetic dynamometer at each limb, with the best trial in each limb used for analysis. The interlimb ratio (injured limb / uninjured limb) of maximum quadriceps strength was analyzed at 6 months. A value of 1 represents symmetric quadriceps strength; a value less than 1 represents less quadriceps strength in the injured compared to uninjured limb.	6 months after anterior cruciate ligament reconstruction.

Collaborators and Investigators

• Sponsor: University of Nebraska
• Collaborators: National Institute of General Medical Sciences (NIGMS)
• Investigators: Principal Investigator: Elizabeth A Wellsandt, DPT, PhD, University of Nebraska

Publications and helpful links

General Publications

• Wellsandt MJ, Weldon N, Werner DM, McManigal ML, Tao MA, Rosenthal MD, Sajja BR, Wichman CS, Baker A, Johnson C, Specht Z, Weaver BA, Knarr B, Nabower C, Wellsandt E. Efficacy of a Squat Visual Biofeedback Program After ACL Reconstruction: Protocol for a Prospective, Parallel, Randomized Controlled Trial. Int J Sports Phys Ther. 2025 Sep 2;20(9):1364-1376. doi: 10.26603/001c.142879. eCollection 2025.

Study record dates

Study Major Dates

• Study Start (Actual): November 11, 2021
• Primary Completion (Actual): June 5, 2024
• Study Completion (Actual): June 5, 2024

Study Registration Dates

• First Submitted: May 2, 2022
• First Submitted That Met QC Criteria: May 2, 2022
• First Posted (Actual): May 6, 2022

Study Record Updates

• Last Update Posted (Actual): February 20, 2026
• Last Update Submitted That Met QC Criteria: February 2, 2026
• Last Verified: June 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Wounds and Injuries; Arthritis; Joint Diseases; Rheumatic Diseases; Leg Injuries; Osteoarthritis; Knee Injuries; Anterior Cruciate Ligament Injuries; Osteoarthritis, Knee; Health Services Administration; Health Care Quality, Access, and Evaluation; Quality of Health Care; Quality Indicators, Health Care; Standard of Care
• Other Study ID Numbers: 0652-21-FB; U54GM115458 (U.S. NIH Grant/Contract)

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