Objective To evaluate the effect of footwear on baseline administration of the modified balance error scoring system (mBESS) in middle school age athletes.

Design Retrospective cohort.

Setting Sixteen middle schools (grades 6–8) within one large public school system.

Participants 342 middle school age athletes (age=11–13 years, M=12.3, SD=0.73; 57.9% boys, 42.1% girls) in Virginia, USA.

Outcome Measures The mBESS was administered to participants while wearing their self-selected footwear (barefoot, cleats, shoes) during annual baseline concussion evaluations. The number of errors committed during the double leg (range=0–10), single leg (range=0–10), and tandem (range=0–10) stances were recorded and summed to calculate the total score (range=0–30).

Main Results Significant differences were observed among the footwear groups for the single leg stance (p<0.001), tandem stance (p<0.01), and the total score (p<0.001). Participants in the shoe group committed fewer errors in the single leg (p<0.001, r=-0.35) and tandem (p=0.003, r=-0.20) stances and had lower total scores (p<0.001, r=-0.36) as compared to the barefoot group. Participants in the shoe group also had lower total scores (p=0.016, r=-0.16) than the cleat group. Participants in the cleat group committed fewer errors in the single leg (p<0.001, r=-0.24) stance and had lower total scores (p=0.001, r=-0.22) than those in the barefoot group.

Conclusions Performance on the mBESS was optimal when middle school age athletes were wearing shoes and the poorest when assessed barefoot. Clinicians should ensure consistent footwear to standardize pre- and post-injury administration of the mBESS in middle school age athletes.