Moment arm data about the metacarpophalangeal (MCP), proximal interphalangeal (PIP), and distal interphalangeal (DIP) joints of the current model (solid black), Buford et al. (blue line), An et al. (red line), and Fowler (grey diamonds) of the flexor digitorum superficialis indices (FDSI), flexor digitorum profundus indices (FDPI), extensor digitorum communis indices (EDCI), and extensor digitorum proprius (EIP) muscles. Shaded area indicates two standard deviations when data was available.