Musculoskeletal injuries such as to the knee’s anterior cruciate ligament (ACL) degrade the operational readiness of our U.S. Service members. These injuries cause decreased physical ability that leads to reduced performance and high re-injury risk. Changes in brain activity as the result of the injury are directly related to the decreased physical performance, affecting the Service member’s motor performance capability in complex or highly reactive military training and operations environments. Unfortunately, current treatments do not restore post-injury Service members’ physical performance, especially when under stress. This deficit has clear consequences for military personnel, as the intense stress and constant need of situational awareness can impair physical performance when returned to active duty. To that end, new therapies are needed to restore Service member performance after injury. This proposal to improve methods to restore Service member performance will address two areas of the Fiscal Year 2017 Peer Reviewed Orthopaedic Research Program Focus Areas: (1) Identify barriers to successful therapy outcomes via the longitudinal quantification of brain changes across the recovery window and (2) Development of optimal physical therapy treatment strategies via assessment of clinically testable and trainable correlates of the brain changes.

This study will quantify how the brain changes after injury across the typical 6-month window of physical therapy. We will also test new functional assessments that have potential to target the brain changes that limit Service member performance. These assessments will support the transition of this research to clinical practice. The proposed tests use low-cost stroboscopic glasses (~$200) that allow a customized decrease in visual feedback during therapy, challenging the brain in a novel manner. We have also developed a virtual reality (VR) therapy that focuses on the brain changes following injury that impair physical performance under stress. This VR approach only requires a smart phone and viewer (~$20). As such, these techniques need minimal time and resources and, most importantly, target the brain in a way that current therapies are unable to do. Another unique advantage of these therapies is their capability to use VR to simulate military-specific scenarios or, using stroboscopic glasses, mimic the visual stress of military training and operations during recovery. This Applied Research Award will provide the knowledge of the time course of brain changes that influence function to implement these new impactful interventions.

A strength of our approach is that aspects of the work will have immediate clinical impact upon completion of the project. There are many therapy modifications that can be implemented to target the brain changes associated with injury, but they are limited by high costs and the need for specialized clinician training. Many of the technologies we propose have low- to no-cost surrogates that can be completed in therapy. An even larger impact will be in the long term, as these data will allow a clinical trial with precise timing of therapy that targets physical deficits and the concurrent brain changes after injury. In this way, an immediate impact can be made, whereby U.S. Service member clinicians can begin bringing the principles of brain adaptations into musculoskeletal therapy in a functionally applicable manner. These data will also set the stage for an even more definitive clinical trial that overlays our suggested interventions with the current standard of care. These synergistic outcomes provide an immediate product that can be clinically implemented and propel further investigations to ensure the truly restored functional capacity of our nation’s Service members.