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| ID | Type | Description | Link |
|---|---|---|---|
| U54GM115458 | U.S. NIH Grant/Contract | View source |
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| Name | Class |
|---|---|
| National Institute of General Medical Sciences (NIGMS) | NIH |
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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.
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.
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| Label | Type | Description | Intervention Names |
|---|---|---|---|
| Control | Active Comparator | Standard care |
|
| Experimental | Experimental | Squat biofeedback intervention |
|
| Name | Type | Description | Arm Group Labels | Other Names |
|---|---|---|---|---|
| Squat Biofeedback | Procedure | 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. |
| 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. |
| 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. |
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Inclusion Criteria:
Exclusion Criteria:
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| Name | Affiliation | Role |
|---|---|---|
| Elizabeth A Wellsandt, DPT, PhD | University of Nebraska | Principal Investigator |
| Facility | Status | City | State | ZIP | Country | Contacts |
|---|---|---|---|---|---|---|
| University of Nebraska Medical Center | Omaha | Nebraska | 68198 | United States |
| PubMed Identifier | Type | Citation | Retractions |
|---|---|---|---|
| 40904719 | Background | 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. |
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| ID | Title | Description |
|---|---|---|
| FG000 | Biofeedback Group | Provided real-time visual feedback on a screen during bilateral squat intervention. |
| FG001 | Control Group | Provided standard verbal instructions during bilateral squat intervention. |
| Title | Milestones | Reasons Not Completed | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Overall Study |
|
1 participant in the control group dropped from the study and did not complete any baseline testing.
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| ID | Title | Description |
|---|---|---|
| BG000 | Biofeedback Group | Provided real-time visual feedback on a screen during bilateral squat intervention. |
| BG001 | Control Group | Provided standard verbal instructions during bilateral squat intervention. |
| Units | Counts |
|---|---|
| Participants |
|
| Title | Description | Population Description | Parameter Type | Dispersion Type | Unit of Measure | Calculate Percentage | Denominator Units Selected | Denominators | Classes |
|---|---|---|---|---|---|---|---|---|---|
| Age, Continuous | 1 participant from the control group dropped from the study and did not complete any baseline test; 1 participant from the squat biofeedback group did not complete the demographics survey during baseline testing. |
| Type | Title | Description | Population Description | Reporting Status | Anticipated Posting Date | Parameter Type | Dispersion Type | Unit of Measure | Calculate Percentage | Time Frame | Units Analyzed | Denominator Units Selected | Arm/Group Information | Denominators | Classes | Analyses | |||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Primary | 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. | Posted | Mean | Standard Deviation | Ratio | Immediately post-intervention (within approximately 1 week after completing intervention) |
|
From study enrollment until 6 months after anterior cruciate ligament reconstruction. Enrollment was completed either before anterior cruciate ligament reconstruction or within 6 weeks after anterior cruciate ligament reconstruction.
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| ID | Title | Description | Deaths (Affected) | Deaths (At Risk) | Serious Events (Affected) | Serious Events (At Risk) | Other Events (Affected) | Other Events (At Risk) |
|---|---|---|---|---|---|---|---|---|
| EG000 | Biofeedback Group | Provided real-time visual feedback on a screen during bilateral squat intervention. |
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| Title | Organization | Phone | Extension | |
|---|---|---|---|---|
| Elizabeth Wellsandt | University of Nebraska Medical Center | 402-559-4309 | elizabeth.wellsandt@unmc.edu |
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| Type | Includes Protocol | Includes SAP | Includes ICF | Document Label | Document Date | Document Uploaded Date | Document File Name |
|---|---|---|---|---|---|---|---|
| Prot_SAP | Yes | Yes | No | Study Protocol and Statistical Analysis Plan | Sep 29, 2023 | Sep 15, 2025 | Prot_SAP_000.pdf |
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| ID | Term |
|---|---|
| D000070598 | Anterior Cruciate Ligament Injuries |
| D020370 | Osteoarthritis, Knee |
| ID | Term |
|---|---|
| D007718 | Knee Injuries |
| D007869 | Leg Injuries |
| D014947 | Wounds and Injuries |
| D010003 | Osteoarthritis |
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| ID | Term |
|---|---|
| D059039 | Standard of Care |
| ID | Term |
|---|---|
| D019984 | Quality Indicators, Health Care |
| D011787 | Quality of Health Care |
| D006298 | Health Services Administration |
| D017530 | Health Care Quality, Access, and Evaluation |
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|
| Standard Care | Procedure | The intervention group will receive standard care post-operative physical therapy. |
|
| 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. |
| BG002 | Total | Total of all reporting groups |
| Mean |
| Standard Deviation |
| Years |
|
| Sex: Female, Male | 1 participant from the control group dropped from the study and did not complete any baseline test; 1 participant from the squat biofeedback group did not complete the demographics survey during baseline testing. | Count of Participants | Participants |
|
| Race (NIH/OMB) | 1 participant from the control group dropped from the study and did not complete any baseline test; 1 participant from the squat biofeedback group did not complete the demographics survey during baseline testing. | Count of Participants | Participants |
|
| Ethnicity (NIH/OMB) | 1 participant from the control group dropped from the study and did not complete any baseline test; 1 participant from the squat biofeedback group did not complete the demographics survey during baseline testing. | Count of Participants | Participants |
|
| Knee Flexion Moment Impulse at Baseline | 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 baseline (pre-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. | 1 participant from the control group dropped from the study and did not complete any baseline testing. | Mean | Standard Deviation | Ratio |
|
| Vertical Ground Reaction Force Impulse at Baseline | 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 was measured. The interlimb ratio (injured limb / uninjured limb) of the vertical ground reaction force during descent and ascent of bilateral squatting was analyzed at baseline (pre-intervention). A value of 1 represents symmetric vertical ground reaction force; a value less than 1 represents a smaller vertical ground reaction force in the injured compared to uninjured limb. | 1 participant from the control group dropped from the study and did not complete any baseline testing. 1 participant from the squat biofeedback group dropped after part of baseline testing was completed with no follow-up testing completed; therefore, their data was not used as a covariate in ANCOVA analyses. | Mean | Standard Deviation | Ratio |
|
| OG001 |
| Control Group |
Provided standard verbal instructions during bilateral squat intervention. |
|
|
|
| Primary | 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. | MRI data acquisition was not initially part of the study protocol and not collected for the first 4 participants (2 in control group and 2 in squat biofeedback group). 1 participant from the control group and 1 participant from the squat biofeedback group dropped from the study and did not complete any MRI testing. Additionally, data from 1 participant in the squat biofeedback group was not usable due to motion artifact and poor data quality. | Posted | Jan 2026 | Mean | Standard Deviation | Percent Change | Baseline (immediately before intervention, 2-6 weeks after anterior cruciate ligament reconstruction) and 6 months after anterior cruciate ligament reconstruction. |
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| Secondary | 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. | Posted | Mean | Standard Deviation | Ratio | 6 months after anterior cruciate ligament reconstruction. |
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| Secondary | 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. | Posted | Mean | Standard Deviation | Ratio | Immediately post-intervention (approximately 1 week after intervention) |
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| Secondary | 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. | Posted | Mean | Standard Deviation | N/A (Ratio) | 6 months after anterior cruciate ligament reconstruction. |
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| Secondary | 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. | Posted | Median | Inter-Quartile Range | Ratio | Immediately post-intervention (within approximately 1 week after completing intervention) |
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| Secondary | 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. | Posted | Median | Inter-Quartile Range | Ratio | 6 months after anterior cruciate ligament reconstruction. |
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| Secondary | 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. | Posted | Median | Inter-Quartile Range | Ratio | Immediately post-intervention (within approximately 1 week after completing intervention) |
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| Secondary | 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. | Posted | Median | Inter-Quartile Range | Ratio | 6 months after anterior cruciate ligament reconstruction. |
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|
| 0 |
| 15 |
| 0 |
| 15 |
| 0 |
| 15 |
| EG001 | Control Group | Provided standard verbal instructions during bilateral squat intervention. | 0 | 17 | 0 | 17 | 0 | 17 |
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| D001168 |
| Arthritis |
| D007592 | Joint Diseases |
| D009140 | Musculoskeletal Diseases |
| D012216 | Rheumatic Diseases |
| Native Hawaiian or Other Pacific Islander |
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| Black or African American |
|
| White |
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| More than one race |
|
| Unknown or Not Reported |
|
| Unknown or Not Reported |
|