Concussion recovery evaluation using the inertial sensor instrumented Y Balance Test

The current sports concussion assessment paradigm lacks reliability, has learning effects and is not sufficiently challenging for athletes. As a result, subtle deficits in sensorimotor function may be unidentified, increasing the risk of future injury. This study examined if the inertial-sensor instrumented Y Balance test could capture concussion induced alterations in dynamic movement control. A cohort of 226 elite Rugby Union, American Football and Ice Hockey athletes were evaluated using the inertial-sensor instrumented Y balance test. Dynamic balance performance was quantified using normalised reach distance, jerk magnitude root-Mean-Squared (Jerk Mag RMS) and gyroscope magnitude sample entropy (Gyro Mag SEn). Concussed athletes who consented to follow-up were evaluated 24 to 48-hours post-injury, and at the point of return to full contact training (RTP). Seventeen athletes sustained a concussion and consented to both the 24 to 48-hour and RTP follow-up testing. Twenty uninjured control athletes were re-tested 6-months following initial screening. Concussed athletes had reductions in normalised reach distance (Cohens D=0.66-1.16) and Jerk Mag (Cohens D=0.57-1.14) 24 to 48-hours post-injury, which returned to pre-injury levels by the point of RTP. There was no significant difference in performance between the baseline and 6-month follow-up in the 20 un-injured athletes (Cohens D=0.06-0.51). There was a statistically significant linear association between Jerk Mag RMS 24 to 48-hours post-injury and the natural log of RTP duration (R2= 0.27 to 0.33). These results indicate that concussed athletes possessed alterations in dynamic movement control 24 to 48-hours post-concussion, which typically returns to pre-injury levels by the point of RTP. Furthermore, evaluation of dynamic movement control 24 to 48 hours post injury may aid in the evaluation of recovery prognosis.