The Control of Movement in the Hand and the Response to Injury.

Hand movements involve the synchronous activation of up to 40 muscles moving up to 20 joints in 27 planes. With a near infinite possible combination of movements in the wrist and hand, control of this movement needs to be incredibly complicated, yet it is automatic and autonomous. The control of these movements is simplified by breaking down the common movements into smaller groups of movement, or synergies, that accomplish everyday tasks. The control of these synergies of hand movement is coordinated within the brainstem and spinal cord, not the sensorimotor cortex, and indeed conscious attempt at control can disrupt, rather than improve, these pathways. This paper is a comprehensive review of the various anatomical, biomechanical, neuroscience and psychological literature concerning this subject and explains the normal movement of the hand, the normal control of this movement and how these movements and control mechanisms are affected by injury and surgery.