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

INTRODUCTION: Despite 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 uses 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.

METHODS: A cross-sectional sample of 6762 student-athletes completed BESS testing. Participants were stratified according to three age groups for each sex. The groups included the following: youth (age, 5-13 yr), males (n = 360), females (n = 246); high school (age, 14-18 yr), males (n = 3743), females (n = 1673); and college (age, 19-23 yr), males (n = 497), females (n = 243). Percentile rankings were determined for each participant to characterize movement of COM in the medial-lateral, anterior-posterior, and trunk rotation directions relative to the entire cohort during the BESS stances.

RESULTS: Overall, postural stability was worse in youth compared with high school and collegiate athletes. Specifically, the CC-PSI was significantly worse in youth male athletes compared with high school and collegiate male athletes (P < 0.001). Females exhibited significantly better scores compared with males in youth and high school cohorts (P < 0.01).

CONCLUSIONS: The CC-PSI provides a quantitative, objective measure of postural stability, overcoming the limitations associated with conventional BESS scoring. Optimal concussion management should use objective age- and sex-specific values in the evaluation of postural stability. The normative values of the CC-PSI may be used in the absence of a baseline BESS evaluation to aid clinical decision making.