Principal component analysis of the balance error scoring system in concussed and healthy high school athletes

Abstract

Objective: Neuropsychological and postural stability testing have become mandated facets of high school concussion management protocols. The Balance Error Scoring System (BESS) is the most cost-effective and quickest objective measure of postural stability. However, previous research has demonstrated individual conditions of the BESS to be unreliable,' excessive'0'11'2 and prone to inaccuracies.12"3 It may be possible to utilize fewer stances while maintaining the integrity of its measures. Our purpose was to examine the score difference, from baseline to post test, for each condition of the BESS over the course of concussion recovery through principal component analysis. Design and Setting: Three groups of BESS data were utilized for interpretation and cross-validation. Experimental group had baseline assessment, concussion diagnosed by their athletic trainer (AT), and post-assessments on days 1, 3, 5, 7 scored by the investigator. The clinical group had baselines and days 1 and 3, administered by participants' AT. Baseline group had only baseline assessments scored by the investigator and an additional AT. Participants: We studied 13 high school athletes in the experimental group, 22 athletes in the clinical group, and 2,811 athletes in the baseline group. Measurements: We assessed postural stability using the Balance Error Scoring System. Results: Double leg firm and foam surfaces failed to meaningfully contribute to assessment of postural stability deficits. Single leg and tandem firm stances were important contributors throughout concussion recovery in the experimental and baseline groups, resulting in the composition of one principal component accounting for 64-71% of the total variance. Conclusion: Double leg firm and foam stances do not aid in the interpretation of postural stability deficits when utilizing the BESS.