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Principal Investigator: CHANDRAMOULI KRISHNAN
Organization: UNIVERSITY OF MICHIGAN AT ANN ARBOR
Fiscal Year: 2024
Award: $211,806
Funding agency: National Institute of Arthritis and Musculoskeletal and Skin Diseases
PROJECT SUMMARY
It is commonplace for individuals after anterior cruciate ligament (ACL) reconstruction to shift mechanical de-
mands away from their surgical knee and limb. This manifests as diminished knee moments and vertical ground
reaction forces in the ACL limb during everyday tasks (e.g., walking, running, standing, landing, etc.) and persists
for as long as 2.5 years after surgery. This pattern of underloading is considered maladaptive, as it has been
linked to re-injury and biological markers that are consistent with the development of post-traumatic osteoarthritis
that affects over 50% of knees 10-20 years after surgical reconstruction. A fundamental gap exists in our under-
standing of how to restore normal loading patterns to the surgical limb after ACL reconstruction. Split-belt tread-
mill training, where treadmill belts are de-coupled such that one limb walks faster than the other, has proven
capable of modifying loading during walking in healthy and neurological populations. Our own pilot data in ACL
reconstructed individuals further supports the premise that split-belt treadmill training can profoundly increase
loading in the ACL knee and limb. However, the effects of split-belt treadmill training in ACL reconstructed indi-
viduals have yet to be studied systematically, so its true efficacy in this population remains unknown. Further,
information regarding the most effective de-coupling speed, what limb to train, and whether acute aftereffects
persist once the split-belt training is removed is not available and is critical to designing an appropriate training
program for ACL reconstructed individuals. The absence of this information serves as the driving force and focus
of the proposed clinical studies. Therefore, we propose studies to define the optimal speed of decoupling nec-
essary for each limb to increase ACL knee loading (Aim 1) and to examine the short-term aftereffects (i.e.,
loading after training) of a single bout of split-belt treadmill training of the ACL and non-ACL limbs (Aim 2). As
we look from this proposal to a randomized clinical trial, our Exploratory Aim will test the benefits of a 6-week
split-belt treadmill training intervention. We hypothesize that knee loading in the ACL reconstructed limb will
increase as the speed on the de-coupled/ACL reconstructed limb belt increases. Further, we hypothesize that
split-belt mediated aftereffects will be significantly higher in a split-belt training condition compared to a tied-belt,
speed-matched control condition. This study is innovative because it systematically evaluates a novel, promising
intervention for ACL reconstructed individuals to modify knee and limb loading, which is a maladaptive biome-
chanical strategy that has no other interventions available capable of minimizing its effects. The proposed re-
search is significant because, if successful, it will identify a treatment approach that may successfully counteract
the knee and limb underloading that plagues ACL reconstructed individuals for years after injury and contributes
to the onset of post-traumatic osteoarthritis.
Terms: <3-D><3-Dimensional><3D><ACL injury><ACL reconstruction><ACL repair><Abnormal gait><Acute><Adherence><Affect><Amendment><Anterior Cruciate Ligament><Behavior><Bilateral><Biological Markers><Biomechanics><Cartilage><Cartilaginous Tissue><Clinical><Clinical Research><Clinical Study><Clinical Trials><Data><Development><Education for Intervention><Educational Intervention><Enrollment><Extremities><Foundations><Future><Gait abnormality><Gait disorder><Gait disturbances><Gait dysfunction><Gait impairment><Grant><Health><History><Impairment><Individual><Injury><Instruction Intervention><Intervention><Intervention Strategies><Knee><Knee Osteoarthritis><Knee joint><Leg><Limb structure><Limbs><Link><Logistics><Mechanics><Mediating><Medical Rehabilitation><Michigan><Modeling><Motion><Neurologic><Neurological><Non-Trunk><Operative Procedures><Operative Surgical Procedures><Outcome><Participant><Patient Recruitments><Patients><Pattern><Placebos><Population><Randomized><Reaction><Reconstructive Surgical Procedures><Recording of previous events><Rehabilitation><Rehabilitation therapy><Reporting><Research><Risk><Running><Sham Treatment><Speed><Surgical><Surgical Interventions><Surgical Procedure><Testing><Time><Training><Training Intervention><Training Programs><Traumatic Arthritis><Traumatic Arthropathy><Treatment Efficacy><Walking><Walking impairment><anterior cruciate ligament injury><anterior cruciate ligament reconstruction><anterior cruciate ligament repair><bio-markers><biologic marker><biomarker><biomechanical><cost><design><designing><developmental><driving force><effective intervention><enroll><histories><improved><injuries><innovate><innovation><innovative><instructional intervention><instrument><intervention efficacy><interventional strategy><knee OA><knee joint OA><knee joint osteoarthritis><life time cost><lifetime cost><mechanic><mechanical><mechanical load><novel><participant recruitment><post-traumatic osteoarthritis><preservation><randomisation><randomization><randomized, clinical trials><randomly assigned><reconstruction surgery><reconstructive surgery><rehab therapy><rehabilitation care><rehabilitative><rehabilitative care><rehabilitative therapy><sham therapy><standard of care><surgery><therapeutic efficacy><therapeutically effective><therapy efficacy><three dimensional><treadmill><treadmill training><treatment strategy>