[Purpose] This study compared the functional and kinematic changes associated with two rehabilitation protocols: bilateral and unilateral movement training.
[Subjects and Methods] Twenty-five patients with chronic stroke were randomly assigned to two training protocols for four weeks of training. Each training session consisted of three tasks. The tasks were performed with either the impaired and unimpaired arms moving synchronously (bilateral training) or with the impaired arm alone (unilateral training). To compare the changes associated with each rehabilitation protocol, functional and kinematic assessments were performed before and after the interventions. The functional state of each patient was measured by the Box and Block Test, and the kinematic variables were assessed by three-dimensional motion analysis. The Box and Block Test was used to assess the functional abilities of the affected upper limb. Kinematic measurements of upper limb movement were measured with a 3-dimensional motion analysis system.
[Results] Results showed that the bilateral movement group had significantly improved motion of the shoulder compared to the unilateral movement group.
[Conclusion] Bilateral movement training should be used to improve upper limb function in patients with chronic stroke.
For motor recovery in patients with stroke, repetitive and intensive practice of voluntary motor control is essential. Utilizing this concept, diverse treatment methods, such as constraint-induced movement therapy1), electromyographic biofeedback2), virtual reality3), and task-oriented training4) have been attempted for recovery of upper-limb control in patients with stroke. However, such treatment methods have focused on unilateral movement of the paretic upper extremity.
Bilateral exercise is a training method that utilizes the non-paretic limb in order to promote functional recovery of the damaged limb through the interlimb coupling effect. To achieve this effect, both hands are drawn into coordinated positions by the muscle groups of identical structures, and combined into one coordinated unit. In order to obtain the interlimb coupling effect in the upper limbs, both the paretic side and the non-paretic side should be repetitively and intensively trained in a simultaneous manner. In this way, the paretic arm will couple with the movement pattern of the non-paretic arm and, accordingly, the function of the paretic arm will improve5). When movement occurs in only one of the upper limbs, inhibition of activation in the same-sided hemisphere takes place; however, while performing symmetric bilateral movement tasks, both the left and the right cerebral hemispheres are activated, reducing inhibition between the hemispheres and thereby promoting recovery of the paretic limb6).
Extensive research has been done to clarify the effects of bilateral exercise, but the results have been controversial. Some research has asserted that the interlimb coupling effect does not improve the performance of the paretic arm in patients with hemiplegia resulting from stroke7). However, other studies have shown that bilateral movement increases the function of the paretic arm in patients with chronic stroke, suggesting the potential role of bilateral movement in recovering upper limb function after stroke8).
Therefore, in order to help clarify the effect of bilateral movement through diverse tasks, the subjects of this study were asked to perform tasks that did not force mirror-symmetric movement but required coordination between both hands. The results derived from this study will provide information that is useful for clarifying the effects of bilateral movement and for systemizing efficient rehabilitation treatment methods.