Toward Restoration of Normative Postural Control and Stability using Neural Control of Powered Prosthetic Ankles

项目总结

PROJECT SUMMARY Falling and fear of falling are pervasive amongst individuals with lower limb amputation (LLA), a large and growing population in the nation. The incidence of falls in individuals with LLA has been often reported during activities requiring adjustments in posture. Transfers (e.g., sit-to-stand) and activities involving dynamic balance control (e.g., reaching and turning) lead to many of the falls in dysvascular transtibial amputees. This evidence highlights the urgent need to address balance and postural stability to enable effective activities of daily living for individuals with LLA. Current prosthesis technology does not allow the amputee users to apply typical postural control strategies at prosthetic joints, limiting postural stability and yielding additional health concerns. Instead, amputees often develop compensatory strategies with the residual (unamputated) joints and intact limb to control balance. The loss of active degrees of freedom (e.g., ankle and/or knee) in the lower limb significantly limits the biomechanical resources available for postural control. Recent advancements in prosthesis and neural interfacing technologies potentially can address the need for improved balance and postural stability in individuals with LLA; however, the related research emphasizes efficient and comfortable walking, rather than balance and postural control. As balance and postural control underly almost all activities performed in an upright position, using prosthesis technologies to directly address the balance stability of amputees is highly needed but rarely investigated in our field. The objective of this proposal is to investigate the effects of training to use direct electromyographic (dEMG) control of a powered prosthetic ankle on transtibial amputees’ (Aim 1) balance and postural stability, (Aim 2) neuromuscular control and coordination, and (Aim 3) cognitive processes, compared to daily prescribed passive devices. This project has clear clinical significance since it addresses the clinical need for improved balance and postural stability in individuals with LLA. Use of dEMG-controlled powered prostheses provides users with additional resources to assist with balance stability and improve balance confidence, which, in turn, improves their community participation and quality of life. At the same time, the proposed project is expected to contribute important knowledge to the field of prosthesis technology, make scientific contributions to the fields of motor control and learning, biomechanics, and cognitive-motor interaction, and benefit physical therapy and amputee rehabilitation.