What is Targeted Muscle Reinnervation (TMR)?

• A. A surgical approach that connects nerves from an amputated limb to remaining unused muscles, which then act as biological amplifiers for prosthetic control
• B. A non-surgical technique that maps nerve signals to control devices
• C. A prosthetic alignment technique
• D. An imaging technique for mapping nerves

Answer: (B)

Targeted Muscle Reinnervation is a surgical procedure where nerves that originally controlled the missing limb are redirected to remaining muscles in the residual limb. Once reinnervated, those muscles generate myoelectric signals that the prosthetic controller can read. Treating the reinnervated muscles as new, volume-flexible sources of neural signals effectively “amplifies” the intent signals, allowing more intuitive and multi-degree-of-freedom control of the prosthesis.

This is inherently a surgical approach because it involves transferring and reinnervating nerves, rather than simply mapping signals or imaging them. The other concepts described—non-surgical mapping of nerve signals, prosthetic alignment, or imaging—do not involve redirecting nerves to new muscle targets, which is the defining feature of TMR.