Broglio SP, Sosnoff JJ, Rosengren KS, McShane K. A comparison of balance performance: computerized dynamic posturography and a random motion platform. Objective To establish the clinical utility of the PROPRIO 5000 as a balance assessment device by establishing convergent validity with the NeuroCom sensory organization test (SOT). Design Cross-sectional. Setting Balance research laboratory. Participants Young adults (N=40; 21.1±1.4y). Interventions Not applicable. Main Outcome Measures Performance on each of the 6 NeuroCom SOT testing conditions and PROPRIO 5000 dynamic motion analysis score. Results Correlational analyses between output variables yielded significant relationships between the dynamic motion analysis score from the 0 to 10 second (r=−.38), 10 to 20 second (r=−.34), and 20 to 30 second (r=−.35) intervals and the SOT composite balance score. Conclusions The initial stages of the PROPRIO 5000 and the NeuroCom SOT battery may evaluate similar aspects of postural control. However, as the magnitude of PROPRIO perturbations increased, the relationship between the devices diverged and the complete PROPRIO assessment is not thought to pair with the SOT assessment. Differences between the 2 devices may be associated with varying degrees of test difficulty and the necessary postural control strategies involved in responding to continual balance perturbations (PROPRIO 5000) or to different sensory inputs (SOT).