Rehabilitation of gait after a stroke can be a frustrating and tiring process. Varying degrees of hemiplegia result from damage to the motor control pathways which are responsible for normal muscle activation. The damage can affect not only the ability to produce force in a muscle, but also the timing of when muscle force is produced. The inability of the CNS to control muscles results in spasticity and/or severe muscle weakness. These circumstances often force a recovering stroke patient to pursue functional movement with a limited neuromuscular capacity. The resultant movements typically deviate from what is considered "normal," on both the affected and unaffected sides. Because there is no direct damage to the neuromuscular pathways on the unaffected side, it is generally assumed that motor control and movement of the unaffected limbs are comparable to that found in normal movement. However, in many movements, especially gait, reciprocal bi-lateral coordination is needed to achieve the greatest success and efficiency of movement. Therefore, it is logical that changes in the neuromuscular control of the affected side will cause compensatory changes in the motor control of the unaffected side. Thus, it is important to consider the interdependent nature of these movements. Does the altered gait pattern of the affected side influence the gait pattern of the unaffected side in a hemiplegic subject?
The purpose of our investigation was to compare the biomechanics of the affected and unaffected sides of a hemiplegic subject during the gait cycle, to determine if changes in the affected side caused compensatory changes in the movement of the unaffected side. Interest in this topic stemmed from experience as an exercise counselor for the subject which stimulated a greater appreciation for the challenges a hemiplegic patient must confront throughout the rehabilitation process. This experience has shown that functional recovery requires gradual progression, exhaustive efforts, and emotional/psychological perseverance on part of the patient. Ideally, a greater understanding of the relationship between motion of the affected and unaffected sides could lead to more effective rehabilitation programs.