Surgical reconstruction of the hand often targets restoration of tip and key pinch, which involves the generation of force by the thumb and the index finger in a specific finger/thumb posture. We report muscle coordination patterns associated with production of maximal force by the index-finger at the distal phalanx in three orthogonal directions. A 3-dimensional, 7-muscle model of the finger reproduced the force and coordination observed with palmar and distal force generation. Analysis of the model showed that palmar force is most sensitive to flexor moment arms at the proximal interphalangeal joint, distal force to dorsal interosseous force production, and lateral force to extensor force production. However, interossei co-excitation observed in lateral force production could not be replicated. One explanation considered was that the model of the metacarpophalangeal joint should include a supination-pronation degree-of-freedom (DOF). However, the addition of a supination-pronation DOF severely compromises the inherent capability of the finger model to produce lateral force. It is concluded that supination-pronation is probably not an independent kinematic DOF at the MCP, and that co-excitation of the interossei may simply be an injury prevention strategy. Lastly, the implications of the multiarticular function of finger muscles are presented in the context of tendon transfers. Specifically, it is believed grasping force could be enhanced should the moment arm of flexor profundus at the proximal interphalangeal joint be increased after a Zancolli Lasso, which is a tendon transfer to correct post-paralysis finger deformity.