# Mi-SPA: Michigan Split-belt Adaptation Paradigm to Improve Knee Loading After Anterior Cruciate Ligament Reconstruction > **NIH NIH R21** · UNIVERSITY OF MICHIGAN AT ANN ARBOR · 2024 · $211,806 ## Abstract 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 plague... ## Key facts - **NIH application ID:** 10809826 - **Project number:** 1R21AR082643-01A1 - **Recipient organization:** UNIVERSITY OF MICHIGAN AT ANN ARBOR - **Principal Investigator:** CHANDRAMOULI KRISHNAN - **Activity code:** R21 (R01, R21, SBIR, etc.) - **Funding institute:** NIH - **Fiscal year:** 2024 - **Award amount:** $211,806 - **Award type:** 1 - **Project period:** 2024-02-15 → 2027-01-31 ## Primary source NIH RePORTER: https://reporter.nih.gov/project-details/10809826 ## Citation > US National Institutes of Health, RePORTER application 10809826, Mi-SPA: Michigan Split-belt Adaptation Paradigm to Improve Knee Loading After Anterior Cruciate Ligament Reconstruction (1R21AR082643-01A1). Retrieved via AI Analytics 2026-05-29 from https://api.ai-analytics.org/grant/nih/10809826. Licensed CC0. --- *[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*