An interventional study of Functional Resistance Training with Brace and Control in Anterior Cruciate Ligament Injury, sponsored by University of Michigan. Completed at 1 site in United States. Open to participants aged 14 Years to 40 Years. Per ClinicalTrials.gov, last updated 2022-01-18.
Sponsored by University of Michigan · Not applicable, Interventional, and Treatment
The purpose of this study is to examine if thigh muscle weakness and the lack of muscle activation that accompanies ACL injury and reconstruction can be improved with functional resistance training.
Profound quadriceps weakness is ubiquitous after anterior cruciate ligament (ACL) reconstruction, and current rehabilitation approaches are not successful in optimizing quadriceps strength and knee function even years after the surgery. We hypothesize that suboptimal strength and functional outcomes after ACL surgery are due to the lack of task-specific exercise elements during strength training. This application seeks to assess whether progressive functional resistance training during gait will significantly improve quadriceps function, neural excitability, and knee mechanics during gait. The proposed studies will not only lay the foundation for a novel training paradigm, but will also improve our understanding of the mechanisms mediating neuromuscular and biomechanical changes after functional resistance training.
Exclusion Criteria:
Participants will receive functional resistance training via a knee brace while walking on a treadmill 2-3 times a week for about 8 weeks.
Other: Functional Resistance Training with Brace
Participants will receive functional resistance training via an elastic band attached at the ankle while walking on a treadmill 2-3 times a week for about 8 weeks.
Other: Functional Resistance Training with Elastic Band
Participants will while on a treadmill without an applied resistance 2-3 times a week for about 8 weeks.
Other: Control
A brace will be strapped to the leg and apply resistance across the knee while subjects walk on a treadmill.
A brace will be strapped to the leg and will not apply resistance across the knee while subjects walk on a treadmill.
An elastic band will be strapped to the leg and apply resistance across the knee while subjects walk on a treadmill.
Quadriceps Muscle Strength
Isometric quadriceps strength was measured with the knee at 60 degrees using an isokinetic dynamometer prior to the intervention and immediately after the intervention. Post-test minus pre-test change scores were calculated.
Time frame: Pre-test measurements were taken at ~9-10 weeks after ACL reconstruction and Post-test measurements were taken at ~18-20 weeks after ACL reconstruction.
Quadriceps Voluntary Activation
Quadriceps voluntary activation was measured using the burst superimposition technique and calculated using the central activation ratio (CAR). The CAR formula is calculated using the peak torque generated immediately prior to the delivery of the stimulus (or the maximum voluntary isometric contraction, MVIC) being divided by the peak torque generated as a result of the electrical stimulus (MVIC plus superimposed burst) and then multiplied by 100. Equation is: MVIC/(MVIC + superimposed burst) × 100. A CAR of 100 represents complete volitional quadriceps activation. Voluntary activation was quantified immediately after the intervenapproximately 9-10 weeks after the int from baseline to the end of intervention will be assessed and compared between groups.
Time frame: Immediately after the intervention or approximately 18-20 weeks after ACL reconstruction
Knee Flexion Angle Symmetry
The knee flexion angle (measured in degrees) during the stance phase was gathered for both limbs using three dimension motion capture and recorded while subjects walked overground. A knee flexion angle symmetry score was computed using the following formula: ensemble average of knee flexion angle of ACL limb minus the ensemble average of knee flexion angle of the non-ACL limb. The mean difference between pre-intervention and post-intervention (post minus pre) knee flexion symmetry scores were calculated for each group. Higher values suggest greater increases in knee flexion angle symmetry from pre-intervention to post-intervention.
Time frame: Pre-intervention values were recorded at ~9-10 weeks after ACL reconstruction and before the start of the intervention. Post-intervention values were recorded after the 8-week intervention (~18-20 weeks after ACL reconstruction)
Knee Moment Symmetry
The sagittal plane knee moment (units Nm) during the stance phase was gathered for both limbs using three dimensional motion capture and recorded while subjects walk overground. A symmetry score was computed using the following formula: ensemble average of the knee moment of the ACL limb (Nm) - ensemble average of the knee moment of the non-ACL limb (Nm). The mean difference between pre-intervention and post-intervention knee moment symmetry scores (post minus pre) were calculated for each group. Higher values represent the greater increases in knee moment symmetry from pre-intervention to post-intervention.
Time frame: Pre-intervention scores were recorded prior to the start of the intervention and approximately 9-10 weeks after ACL reconstruction. Post-intervention scores were recorded after the 8 week intervention or approximately 18-20 weeks after ACL reconstruction
| Milestone | Functional Resistance Training With Brace | Functional Resistance Training With Elastic Band | Control |
|---|---|---|---|
| Started | 10 | 10 | 10 |
| Completed | 10 | 8 | 8 |
| Not completed | 0 | 2 | 2 |
| Withdrew: Covid-19 research shutdown | 0 | 2 | 2 |
Isometric quadriceps strength was measured with the knee at 60 degrees using an isokinetic dynamometer prior to the intervention and immediately after the intervention. Post-test minus pre-test change scores were calculated.
| Nm/Kg | Functional Resistance Training With Brace | Functional Resistance Training With Elastic Band | Control |
|---|---|---|---|
| Quadriceps Muscle Strength | .674 ± .124 | .398 ± .130 | .279 ± .130 |
Quadriceps voluntary activation was measured using the burst superimposition technique and calculated using the central activation ratio (CAR). The CAR formula is calculated using the peak torque generated immediately prior to the delivery of the stimulus (or the maximum voluntary isometric contraction, MVIC) being divided by the peak torque generated as a result of the electrical stimulus (MVIC plus superimposed burst) and then multiplied by 100. Equation is: MVIC/(MVIC + superimposed burst) × 100. A CAR of 100 represents complete volitional quadriceps activation. Voluntary activation was quantified immediately after the intervenapproximately 9-10 weeks after the int from baseline to the end of intervention will be assessed and compared between groups.
| percentage of activation | Functional Resistance Training With Brace | Functional Resistance Training With Elastic Band | Control |
|---|---|---|---|
| Quadriceps Voluntary Activation | 73.19 ± 6.56 | 69.55 ± 7.72 | 68.29 ± 7.19 |
The knee flexion angle (measured in degrees) during the stance phase was gathered for both limbs using three dimension motion capture and recorded while subjects walked overground. A knee flexion angle symmetry score was computed using the following formula: ensemble average of knee flexion angle of ACL limb minus the ensemble average of knee flexion angle of the non-ACL limb. The mean difference between pre-intervention and post-intervention (post minus pre) knee flexion symmetry scores were calculated for each group. Higher values suggest greater increases in knee flexion angle symmetry from pre-intervention to post-intervention.
| Angle Symmetry (degrees) | Functional Resistance Training With Brace | Functional Resistance Training With Elastic Band | Control |
|---|---|---|---|
| Knee Flexion Angle Symmetry | 3.230 (0.658 to 5.803) | 0.556 (-0.857 to 1.970) | 0.846 (-0.917 to 2.608) |
The sagittal plane knee moment (units Nm) during the stance phase was gathered for both limbs using three dimensional motion capture and recorded while subjects walk overground. A symmetry score was computed using the following formula: ensemble average of the knee moment of the ACL limb (Nm) - ensemble average of the knee moment of the non-ACL limb (Nm). The mean difference between pre-intervention and post-intervention knee moment symmetry scores (post minus pre) were calculated for each group. Higher values represent the greater increases in knee moment symmetry from pre-intervention to post-intervention.
| Moment Symmetry (Nm) | Functional Resistance Training With Brace | Functional Resistance Training With Elastic Band | Control |
|---|---|---|---|
| Knee Moment Symmetry | .0144 (-0.057 to 0.086) | 0.132 (0.0408 to 0.224) | -0.042 (-0.078 to -0.0074) |
Collected over Adverse event data was collected during the course of the study. The timeframe of the study was approximately 5 months. Adverse events during a period from about 8 weeks after ACL reconstruction to about 28 weeks after reconstruction.. Non-serious events are listed at a 0% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Functional Resistance Training With Brace | 0/10 (0%) | 0/10 (0%) | 0/10 (0%) |
| Functional Resistance Training With Elastic Band | 0/10 (0%) | 0/10 (0%) | 0/10 (0%) |
| Control | 0/10 (0%) | 0/10 (0%) | 0/10 (0%) |
| Age, Continuous(years) | Functional Resistance Training With Brace | Functional Resistance Training With Elastic Band | Control | Total |
|---|---|---|---|---|
| Mean | 18.8 ± 6.2 | 22.1 ± 4.5 | 20.4 ± 5.6 | 20.4 ± 5.4 |
| Sex: Female, Male(Participants) | Functional Resistance Training With Brace | Functional Resistance Training With Elastic Band | Control | Total |
|---|---|---|---|---|
| Female | 6 | 6 | 6 | 18 |
| Male | 4 | 4 | 4 | 12 |
| Race (NIH/OMB)(Participants) | Functional Resistance Training With Brace | Functional Resistance Training With Elastic Band | Control | Total |
|---|---|---|---|---|
| American Indian or Alaska Native | 0 | 0 | 0 | 0 |
| Asian | 0 | 1 | 2 | 3 |
| Native Hawaiian or Other Pacific Islander | 0 | 0 | 0 | 0 |
| Black or African American | 1 | 2 | 0 | 3 |
| White | 9 | 7 | 8 | 24 |
| More than one race | 0 | 0 | 0 | 0 |
| Unknown or Not Reported | 0 | 0 | 0 | 0 |
| Region of Enrollment(participants) | Functional Resistance Training With Brace | Functional Resistance Training With Elastic Band | Control | Total |
|---|---|---|---|---|
| United States | 10 | 10 | 10 | 30 |
| Height(centimeters) | Functional Resistance Training With Brace | Functional Resistance Training With Elastic Band | Control | Total |
|---|---|---|---|---|
| Mean | 174 ± 11.2 | 172.3 ± 7.9 | 169.8 ± 9.0 | 172.0 ± 9.4 |
| Mass(kilograms) | Functional Resistance Training With Brace | Functional Resistance Training With Elastic Band | Control | Total |
|---|---|---|---|---|
| Mean | 70.1 ± 10.5 | 70.3 ± 12.2 | 70.2 ± 13.3 | 70.2 ± 12.0 |
| Time Since Surgery to Baseline Study Testing(weeks) | Functional Resistance Training With Brace | Functional Resistance Training With Elastic Band | Control | Total |
|---|---|---|---|---|
| Mean | 8.9 ± 2.6 | 9.5 ± 2.5 | 10.3 ± 3.1 | 9.6 ± 2.7 |
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Anterior Cruciate Ligament Injuries→
University of Michigan