Amputation below the elbow (transradial) is the most common form of major upper limb amputation, affecting several thousand individuals in the United States. Although these individuals have more residual muscles than higher level amputees, they have at most only two residual muscles to control a prosthetic hand using conventional control. Using pattern recognition, transradial amputees cannot perform as many hand grasp movements as individuals with higher level amputations who have had TMR because transferred nerves carry control information for intrinsic hand finger, and thumb muscles, which is not available to individuals with a transradial amputation.
Performing transradial TMR, in which residual nerves from intrinsic hand muscles are transferred to remaining forearm muscles, may provide individuals with intuitive control over prosthetic wrist and hand movements, and potentially allows for more intricate grasping patterns.
Currently, we are evaluating ways to quantify the control information provided by intrinsic hand muscles to guide future transradial TMR procedures.