[Purpose] This study was conducted in order to compare muscle activation level on the affected and unaffected limb according to the recovery level of upper limb between bilateral activity with hands clasped and bilateral activity with pilates ring.
[Subjects and Methods] Twenty inpatient who have had a stroke were recruited. Subjects were divided into two groups by the Fugl-Meyer Assessment of Motor Function score of moderately recovered group and well recovered group. The muscles activation of upper extremity and Co-Contraction Ratio (CCR) were analyzed.
[Results] In the muscles activation of the well group, trapezius, anterior deltoid, and triceps muscles of affected side and biceps muscles of both sides were significantly higher when activity with pilates ring than activity with hands clasped. CCR of both side in the well group was significantly decreased during activity with pilates ring and in the moderate group, CCR of affected side was significantly decreased during activity with pilates ring.
[Conclusion] Bilateral activity with a pilates ring is more effective than activity with hands clasped for the facilitation of muscle activation and coordination in stroke patients.
Functional limitation imposed due to a paretic upper limb affects more than 80% of stroke survivors1) . Upper limb impairment is the leading cause of limitation of motor function. Therefore, restoration of upper limb function is an essential aspect of stroke rehabilitation for regaining functional independency2) . An abnormal pattern of upper limb movement may occur caused by the compensation for muscle paralysis and imbalance. By training to perform a functional task, movement re-education is used to treat the abnormal pattern of muscle weakness3) . Although rehabilitation specialists are trying various approaches to facilitate the restoration of upper limb function, rehabilitation of upper limb function remains a challenge. Consequently, a number of researchers and therapists are seeking more effective therapeutic techniques of upper limb rehabilitation to restore voluntary motor control. Bilateral training (BT) is a therapeutic technique of upper limb rehabilitation. A recent meta-analysis revealed that BT has a positive effect on poststroke upper limb rehabilitation4) . BT induces motor synergy between limbs to activate the motor capacity of the affected limb. In other words, voluntary movements of the unaffected limb facilitate voluntary movements of the affected limb5) . Activation of the primary and supplementary motor cortex for the unaffected limb increases voluntary muscle contraction of the affected limb during symmetrical movements6) . Even though BT is performed by using both the unaffected and the affected limbs simultaneously, most studies have reported the effect of BT on the affected limb. Morris & Wijck reported one randomized controlled trial that investigated the effect of BT on the unaffected limb. In that report, subjects were classified into two groups, the bilateral group and unilateral group divided who scored ≤6 on the motor assessment7) . However, no study has addressed the effect of upper limb muscle activation on the unaffected limb during bilateral activity and the comparison of change in activity between the affected and unaffected limbs. The effect of BT on the recovery level of the upper limb remains unclear. BT includes various activities such as targeted reaching activity using a peg, grasping and bringing a glass to the mouth, picking up and placing a towel, and manipulating and playing cards. While various activities are used, it is important to ensure that the movements involve both the upper limbs4) . For assessing bilateral activity, movements involving hand clasped or grasping and lifting up an instrument such as a rod are used. However, no study has investigated the difference in amounts of upper limb muscle activation between bilateral activity with hands clasped and bilateral activity while lifting an instrument. Therefore, the purpose of the present study was to compare the muscle activation level on the affected and unaffected limbs according to the recovery level of the upper limb between bilateral activity with hands clasped and bilateral activity with a pilates ring.