The application of the muscle synergy hypothesis enables a large reduction in the number of model parameters due to a low dimensional structure at the motoneuron activation level. We discuss these results and the current state of the muscle synergy hypothesis. The muscle synergy hypothesis has received considerable attention in the neuroscience community (see 1 for a review). muscles, and neural elements, increase to make the models more biologically plausible, the number of parameters increases signicantly. Several recent studies have examined this hypothesis, providing evidence both in support and in opposition to it. In this review we examine one particular hypothesized level of control: that the CNS produces movement through the flexible combination of groups of muscles, or muscle synergies. We discuss these results and the current state of the muscle synergy hypothesis.ĪB - A long standing goal in motor control is to determine the fundamental output controlled by the CNS: does the CNS control the activation of individual motor units, individual muscles, groups of muscles, kinematic or dynamic features of movement, or does it simply care about accomplishing a task? Of course, the output controlled by the CNS might not be exclusive but instead multiple outputs might be controlled in parallel or hierarchically. Several recent studies have examined this hypothesis, providing evidence both in support and in opposition to it. Recently, the method of synergy studies within the framework of the UCM hypothesis has been developed to studies of multi-muscle synergies stabilizing potentially important variables such as coordinate of the center of pressure (COP) during postural tasks (Krishnamoorthy et al. The association of several muscle groups contracting simultaneously as a single functional unit, e.g. N2 - A long standing goal in motor control is to determine the fundamental output controlled by the CNS: does the CNS control the activation of individual motor units, individual muscles, groups of muscles, kinematic or dynamic features of movement, or does it simply care about accomplishing a task? Of course, the output controlled by the CNS might not be exclusive but instead multiple outputs might be controlled in parallel or hierarchically. AJ was supported by National Institute of Child Health and Human Development/National Institutes of Health Grant 5T32HD007418-17. We hypothesize that due to cocontraction, there will be fewer muscle synergies in individuals with knee OA compared to healthy older adults, and that the. Researchers have defined muscle synergy in different ways. This is particularly important in medical fields and especially in rehabilitation.

Work was supported by National Institutes of Health Grant AR053608-01 (to MCT). Finally, we briefly discuss an inherent difficulty in testing the muscle-synergy hypothesis, which arises when population level optimization is assumed. The muscle synergies hypothesis suggests different strategies of the CNS to perform tasks with and without neurological conditions. T1 - The case for and against muscle synergies

Muscle synergy hypothesis