Integration of sensory feedback in limb prosthese

Amputees using lower limb prosthetics must rely on socket-stump interaction forces and visual feedback for their perception of the prosthetic leg. This can lead to poor confidence in using the leg and lead to gait compensations which can increase the risk of musculoskeletal disorders, and poor balance which can lead to falls. Additionally, due to the absence of an ankle, no plantarflexion can be achieved during push off when walking which reduces the gait efficiency for amputees and can only be corrected through use of an active ankle. Providing sensory feedback can aid these issues and enable the use of an active ankle. This has previously been achieved through invasive methods or surgical procedures, but such procedures are not feasible for the whole amputee population as they cannot be done retrospectively. A feedback paradigm congruent with normal muscle activation during walking and prosthetic ankle behaviour may even be able to induce realistic sensations in the phantom limb. For this reason, the use of invasive intramuscular electrodes which have a minimally invasive implant procedure, for stimulation is being investigated for use with prosthetic ankles in transtibial patients. Invasive IM electrodes can be used to stimulate the muscle afferents and give the sensation of changes in muscle length. The purpose of the PhD is to evaluate how IM stimulation using these electrodes can be used induce realistic sensation and improve gait of transtibial amputees.