Proprioception Restoration for Upper Limb Amputees

Event Date:
January 20th 9:00 AM - 10:00 AM

Speaker: Jonah Mudge

Research Advisor: Prof. Graczyk


Title: Proprioception Restoration for Upper Limb Amputees


Abstract: When an amputation occurs, proprioception in the missing limb is lost and previously simple motor tasks can become much more difficult or even impossible to accomplish. Proprioception is the body’s sense of limb position and velocity in space and is a vital part of motor planning. Current cutting-edge neuroprostheses can elicit a rough sensation of proprioception using peripheral neural interfaces in amputees. However, these devices do not yet fully replicate the proprioceptive acuity of an intact limb. One limiting factor is the gap in literature concerning the design and implementation of proprioception-specific stimulation paradigms. Many previous stimulation studies also do not account for the agonist-antagonist muscle interactions that are integral to natural proprioceptive sensation. Additionally, it is unclear what the primary mechanism of proprioceptive sensation through peripheral nerve stimulation is, whether it be direct muscle spindle fiber activation or off-target muscle activation. Another challenge is determining how this mechanism may differ between amputees with or without TMR (Targeted Muscle Reinnervation) or TSR (Targeted Sensory Reinnervation). Previous data suggest an involvement of the contraction of the muscles of the residual limb in peripherally-stimulated proprioceptive sensations in the phantom hand, as proprioception and residual muscle EMG appeared to be correlated. Further data demonstrate an effect of pulse frequency on proprioceptive stimulation. Based on these preliminary results, I propose a framework for developing a new proprioceptive stimulation paradigm through the comparison of agonist and antagonist pulse frequency modulated stimulation in unilateral upper limb amputees with and without TMR/TSR.