A system and method for improving limb function through the use of percutaneous mechanical and neural interfaces. The system generally uses a hollow long bone axial rod that is inserted into the long bone medullary cavity. A transfer rod with a central channel is mounted to the long bone axial rod. An exterior body attachment is connected to the transfer rod and attachment rings attach muscle groups, fascia layers and dermal layers to the transfer rod. Additionally, the system is configured to collect and transmit nerve signaling data to an external processor and additionally configured to transmit data from the external processor to the plurality of nerves.