Wearable Technology to Quantify Patient Reported Outcome Measures to Guide Rehabilitation Following Anterior Cruciate Ligament Reconstruction

The anterior cruciate ligament (ACL) stabilizes the knee joint to prevent internal rotation. ACL injuries are common for athletes in high-cutting sports, affecting female athletes at a greater incidence compared to male athletes. Wearable devices and digital health technologies, broadly speaking, have become increasingly utilized in clinical trials to quantify patient reported outcome measures to complement subjective assessments. In the context of sports medicine, wearable technology serves as an objective and continuous means to complement athlete ratings of perceived exertion. One such biomarker of interest is muscle oxygen saturation (SmO
2
), which is the ratio of oxygenated hemoglobin to total hemoglobin. A decrease in SmO
2
is indicative of greater muscle exertion, higher energy output, and greater oxygen consumption. Current assessments for ACL rehabilitation employ subjective means and lack the integration of continuous, internal data. This study bridges this gap via the measurement of SmO
2
to guide the return to play (RTP) process following ACL reconstruction (ACLR). Preliminary results from one patient demonstrate significant differences between the surgical and contralateral limbs during max-minute fan bike and Tabata fan bike exercises at both 6-and 9-month trials following ACLR. In the bilateral leg press exercise, significant differences were found between the surgical and contralateral lower extremities at 6-months but not at the 9-month trial. Data collection will also occur at 12-months post ACLR to further momtor differences between surgical and contralateral limbs in the RTP process. These results provide the impetus to enable the interoperability of data gathered from wearable devices into data management systems for optimizing performance and health of athletes following injury.