Exploring to learn synergies and its applications in injuries affecting the upper limb

This chapter starts with arguing that rehabilitation should exploit motor learning to improve its effectiveness. To advance motor learning during rehabilitation, the focus should be on the processes underlying learning. Starting from the framework of Dynamic Systems to motor coordination, we argue that synergies are learned when mastering a new task. Synergies are temporary organizations of degrees of freedom to perform a specific task or function. Synergies emerge from interactions among task, organism, and environmental constraints in a self-organizing manner and have stability properties. Each task has a unique set of constraints, and hence, a novel task has specific interactions among constraints from which the synergies for that task emerge. Hence, learning a novel task requires learning new synergies. This learning process entails destabilizing the current synergy. Following the destabilization, a search for the new synergy takes place in the space made up by the degrees of freedom relevant for the new task. When the new synergy is found, it is then stabilized. We point out ways to translate the knowledge on learning new synergies to advance rehabilitation practices in learning to use a hand prosthesis and learning new tasks after a stroke. We think these ideas might improve effectiveness of rehabilitation through exploiting knowledge in motor control and motor learning.