Neuromuscular strategies for dynamic finger movements: a robotic approach

Human hand control mechanisms are extremely complex and currently there is no solution to restore full function to a paralyzed hand. The optimal solution is to use either cortical signals or desired joint angles/torques to stimulate existing muscles. One of the limiting factors in achieving this goal is a poor understanding of the relationship between the input (i.e. neural signals to muscles) and the output (i.e. joint movements) in the system (i.e. hand). There are infinitely many sets of muscle forces that generate any given set of joint torques because of redundancy and the ability to co-contract antagonist muscles. In this paper, we describe a methodology to estimate and compare biological and robotic solutions for the muscle forces for a given set of dynamic joint movements. Our preliminary results indicate that the robotic solution obtained by finding the minimum forces resembles the biological solution. This methodology may allow us to identify the neuromuscular control strategies used during dynamic finger movements.