Plan: The proposed 4-year study has two parts: 1) Cross-sectional study (Aim I: Balance Assessment) to identify and characterize maladaptive balance control strategies after mTBI compared to healthy controls and 2) Interventional randomized pilot study (Aim II: Balance Rehabilitation) using a novel ABF rehabilitation technique to ameliorate maladaptive balance control strategies after TBI. Subjects in Aim II will be a subset from Aim I and studies will occur simultaneously.