Many stroke survivors have residual sensorimotor deficits that impact negatively on balance and quality of life. The purpose of this review is to provide an overview of the impairments in motor control following stroke and the impact of those impairments on muscle activation patterns during postural control in stroke. Motor control impairments following stroke result in force production that is slow, weak and lacking in precision making it difficult to produce a fast rate of force development with sufficient magnitude to be effective for postural responses. Whether postural perturbations require feedback or feedforward responses, there is impairment to the timing, magnitude and sequencing of muscle activation following stroke. The impairment in muscle activation is dependent on the extent of the motor control impairments and strategies used by the individuals following stroke to compensate for the impairments. The central nervous system uses a variety of mechanisms to improve the muscle activation patterns needed for the recovery of postural responses following stroke.
Garland is with the Dept. of Physical Therapy, University of British Columbia, Vancouver, British Columbia. Gray and Knorr are with the School of Physical Therapy, University of Western Ontario, London, Ontario.