STUDY DESIGN: Observational. BACKGROUND: The Star Excursion Balance Test (SEBT) is used to evaluate dynamic postural control and screen for injury risk. No prior studies have investigated whether the quality of movement during the SEBT has clinical value and can adequately predict injury. PURPOSE: To develop a visual assessment tool and evaluate the relationship between movement quality and SEBT outcomes. METHODS: One hundred healthy subjects were included. Baseline demographic, limb length, and individual SEBT performance data were collected. SEBT outcomes were obtained and used to classify individuals as at-risk or not at-risk. At-risk individuals demonstrated anterior right/left reach distance difference greater than 4 cm, and/or normalized composite reach distance less than 89.6% for males or 94% for females. Three independent reviewers, blinded to SEBT outcomes, assessed the anterior reach test on videotape. Reviewers underwent training on a scoring system to assess movement quality at the trunk, pelvis, and knee. The total score of movement faults was used to determine interrater reliability and calculate sensitivity and specificity, in addition to positive and negative predictive values of SEBT outcome. RESULTS: Seventy-one subjects were classified as at risk. Interrater reliability of movement scoring was poor-moderate for the trunk and pelvis (kappa=0.18-0.43), and moderate for the knee (kappa=0.5-0.6). Rater agreement for total movement score was fair-moderate (W=0.64-0.73). Rater assessment of aberrant movement was not predictive of SEBT performance. However, subjects deemed at risk had fewer movement faults per rater assessment. Raters displayed moderately strong specificity (0.59-0.82) and poor sensitivity (0.14-0.39) in knee assessment to detect at risk performance on the SEBT. CONCLUSION: Clinical observation of knee movement demonstrated acceptable interrater reliability and moderately strong specificity to detect at-risk SEBT outcome. Total movement score across all regions demonstrated fair-moderate agreement. Subjects who were at risk tended to have fewer movement faults.