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Completed

NCT Number: NCT03282565

Functional Resistance Training to Improve Knee Function After ACL Reconstruction

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.

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Key information

Conditions

Anterior Cruciate Ligament Injury Anterior Cruciate Ligament Injuries Knee Injuries Leg Injuries Wounds and Injuries

Age range

14 year–40 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

University of Michigan

Ann Arbor, Michigan, 48109, United States

About this study

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.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • aged 14-40 years
  • suffered an acute, complete ACL rupture
  • willingness to participate in testing and follow-up as outlined in the protocol
  • English-speaking

Exclusion criteria

  • inability to provide written informed consent
  • female subjects who are pregnant or are planning to become pregnant
  • previous ACL injury
  • previous surgery to either knee
  • bony fracture accompanying ACL injury
  • patients who experienced a knee dislocation;
  • patients who are contraindicated for transcranial magnetic stimulation (e.g., metal implants in head, unexplained recurrent headaches, history of seizures, epileptogenic drugs, active psychiatric illness, etc.).

Treatment and study plan

Functional Resistance Training with Brace

Other

A brace will be strapped to the leg and apply resistance across the knee while subjects walk on a treadmill.

Control

Other

A brace will be strapped to the leg and will not apply resistance across the knee while subjects walk on a treadmill.

Functional Resistance Training with Elastic Band

Other

An elastic band will be strapped to the leg and apply resistance across the knee while subjects walk on a treadmill.

Primary outcomes

  1. Quadriceps Muscle Strength

    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.

    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.

Secondary outcomes

  1. Quadriceps Voluntary Activation

    Time frame: Immediately after the intervention or approximately 18-20 weeks after ACL reconstruction

    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.

  2. Knee Flexion Angle Symmetry

    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)

    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.

  3. Knee Moment Symmetry

    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

    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.

Sponsors and collaborators

Lead sponsor

University of Michigan

Other

Collaborators

  • Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
  • National Institutes of Health (NIH)

Registry information

Official study title

Functional Resistance Training During Gait: A Novel Intervention to Improve Knee Knee Function After ACL Reconstruction

Important dates

Study start
2018
Primary completion
2020
Study completion
2020
First posted
Sep 14, 2017
Registry last updated
Jan 18, 2022

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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