Cleveland Clinic-Postural Stability Index Norms for the Balance Error Scoring System

INTRODUCTIONDespite the widespread utilization of the Balance Error Scoring System (BESS) in the evaluation of concussion, it has been criticized for its error-based scoring that is susceptible to floor and ceiling effects and substantial inter-rater variability. A biomechanical outcome, Cleveland Clinic-Postural Stability Index (CC-PSI), has been developed as an alternative to subjective BESS scoring. The CC-PSI utilizes inertial sensor data within a mobile device to provide an objective measure of postural sway during the BESS. This project aimed to determine the effect of age and sex on the CC-PSI and report normative values for healthy, active children, adolescents, and young adults. METHODSA cross sectional sample of 6,762 student-athletes completed BESS testing. Participants were stratified according to three age groups for each sex. Groups includedyouth (age 5-13)males (n=360), females (n=246), high school (age 14-18)males (n=3743), females (n=1673), and college (age 19-23)males (n=497), females (n=243). Percentile rankings were determined for each participant to characterize movement of center of mass in the medial-lateral, anterior-posterior and trunk rotation directions relative to the entire cohort during the BESS stances. RESULTSOverall, postural stability was worse in youth compared to high school and collegiate athletes. Specifically, the CC-PSI was significantly worse in youth male athletes compared to high school and collegiate male athletes (p