To provide realistic sensory feedback it is necessary to give the user a sense of the limb configuration and position in space. Naturally this feedback (aka proprioception) comes from muscle spindles and other sensory receptors located in the muscles. These are not present in a prosthetic device. We are developing a detailed models of the hand that describe the dynamics of the neuromuscular system, including proprioceptive feedback signals as well as muscle activations, lengths and forces. Our long-term goal is that these models will be used to provide enhanced function to prosthesis users by providing natural control.