BACKGROUND:Biomechanical screening assessments are used to provide useful information about an athlete's movement proficiency. Clinically, movement proficiency is typically evaluated visually. This can result in low levels of agreement, leading to difficulties in ensuring consistent athlete assessment. OBJECTIVE:The objective was to determine levels of agreement within and between physical therapists and physical therapist students when visually evaluating athletes' movement proficiency during biomechanical screening assessments. DESIGN:This was an observational study. METHODS:Twenty-seven physical therapists and 20 physical therapist students assessed 100 video recordings of athletes performing 4 lower-extremity biomechanical screening assessments: squat, lunge, single leg squat, and deadlift. Analysis was completed on conditioned and unconditioned data. In the conditioned data, technique deviations were induced purposefully by the athletes. In the unconditioned data, deviations occurred naturally due to increased weight or movement complexity. In order to determine levels of agreement in the assessments, participants were required to classify the athletes' movement as acceptable or aberrant. Each participant assessed the same video recordings on 2 separate occasions at least 30 days apart. Agreement levels were determined using Cohen κ and Fleiss κ. RESULTS:Kappa scores at an interrater level ranged from 0.18 to 0.53, and intrarater agreement ranged from 0.38 to 0.62. Levels of agreement were higher in the conditioned data compared with the unconditioned data. Overall, the lunge and squat produced higher levels of agreement than the deadlift and single-leg squat. Students and physical therapists demonstrated similar levels of agreement. LIMITATIONS:Screening assessments were evaluated through the use of video analysis. CONCLUSIONS:Greater efforts are needed to ensure standardization of movement analysis.