Optimize Performance and Mitigate Falls in Warfighters with Lower Limb Trauma and/or Loss

Loss of balance and associated falls are a significant problem following lower limb trauma and/or loss in both Warfighters and civilians. Over half of lower extremity amputees report falling in the past year and 66% of above-knee amputees fall annually, twice the rate of able-bodied elderly adults. Impaired balance and fear of falling commonly leads to decreased activity levels, participation in social activities and an increased fear of falling. Balance deficits persist even after advanced rehabilitation and while using current state-of-the-art prosthetic and orthotic devices. Research conducted on cutting-edge systems such as mechanical perturbation treadmills and virtual reality environments show promise, but their clinical utility is limited due to cost and/or space requirements. Furthermore, such systems lack important sensory feedback, including high fidelity extero- and proprioceptive information regarding limb load and position that are highly relevant for gait and balance function. Consequently, there is a need for a quantitative, low-cost, user-friendly, in-clinic tool to enhance fall-mitigation training and help maximize performance of Warfighters with lower limb trauma and/or loss to facilitate return-to-duty and maximize the chance for re-deployment to theater. RxFunction Inc. and Liberating Technologies, Inc. (LTI) propose to integrate their technologies into a system called the Return to duty Lower Extremity Augmented RehabilitatioN (ReLEARN) system, to facilitate rehabilitation of patients with lower limb trauma/loss. The system combines the commercialized Walkasins™ sensory neuroprosthesis technology developed and manufactured by RxFunction, and a balance monitoring system with Inertial Measurement Units (IMUs) and a human biomechanical model developed by LTI. Walkasins is a sensory substitution technology, a non-invasive neuroprosthesis, intended to replace lost nerve function in patients with sensory peripheral neuropathy (PN) and balance problems using vibrotactile stimuli. In an ongoing clinical trial, Walkasins use is showing improved clinical outcomes related to gait and balance, decreased fall rates, decreased number of fallers and less severe injuries after a fall. Individuals with PN and amputation face similar issues, loss of distal somatosensory feedback important for balance that could be addressed through sensory substitution at a more proximal location on the skin. Our proposed solution will combine pressure measurements under the foot using Walkasins with IMUs and model data provided by the LTI technology. ReLEARN will provide clinically relevant sensory feedback to the patient in real-time and objective outcomes data to the clinician to enhance rehabilitation. This important sensory information has not previously been available in physical therapy clinics. Furthermore, ReLEARN will have applications for the civilian physical therapy market in amputees and other patient populations in need of neurorehabilitation.