SUMMARY

Musculoskeletal disorders of the back are an extremely prevalent health issue across the workforce in the United States. This is especially a concern in industries involving manual materials handling tasks that cause low back pain. While these injuries are generated by both symmetric and asymmetric lifting, asymmetric movements are often more damaging. Exoskeleton technology has become an increasingly popular preventative measure to low back pain, but many devices do not assist in asymmetry. Thus, I present a new system called the Asymmetric Back Exosuit (ABX). The ABX addresses this important gap in the field through unique design geometry and active cable-driven actuation. The suit allows the user to move in a wide range of lumbar trajectories while the “X” pattern cable routing allows for variable assistance application for these trajectories, enabling assistance during asymmetric movements. As indicated by a biomechanical model of the system made in OpenSim, the cable forces can be mapped to effective lumbar torque assistance for a given lumbar trajectory, allowing for intuitive controller design over the complex kinematic chain for varying lifting techniques. An early human subject study indicated that the ABX was able to reduce low back muscle activation during symmetric and asymmetric lifting by an average of 37.8% and 16.0%, respectively, compared to lifting without the exosuit. This was expanded to a larger biomechanics study of the ABX from which preliminary results of three subjects are discussed. These evaluations indicate the potential for the ABX to reduce lumbar injury risk during symmetric and asymmetric manual materials handling tasks.