A Time-Interval Analysis of Repetitive Motion Injuries in a Sorting Facility

This paper documents research into repetitive motion injuries (RMIs) occurring at a used garment sorting facility, with a focus on the Poisson distribution model and associated time interval analysis. Time interval analysis is used to confirm existence of a Poisson process. The Poisson process and distribution is then implemented to model the occurrence of RMIs at the target facility, as well as employed in a proactive effort to track and reduce RMIs. As a major player within this labor-intensive industry, the industrial partner experiences a significant number of repetitive motion injuries (RMIs). Analysis is provided on the Poisson process, and the salient RMI risk factors and ergonomic principles that might affect application of the Poisson distribution model. This paper also reviews proposed methodologies for collecting RMI risk factor data, tracking RMI accident or “incident” data, gathering population-specific anthropometric data, and developing RMI hazard reduction strategies. The Poisson model is presented as a structured methodology for the prediction and control of repetitive motion injuries.