Surface electromyographic examination of the coordination of the spastic upper limb muscles of stroke survivors / 中华物理医学与康复杂志

ABSTRACT

Objective To explore any changes in the surface electromyography (sEMG) signals measured on the spastic upper limb muscles of stroke parents during maximum isometric voluntary contraction and to analyze any abnormal synergy patterns quantitatively in order to design better rehabilitation programs for developing coordination.Methods Ten stroke survivors with hemiparesis were selected into a patient group and ten healthy counterparts were recruited into a control group.sEMG signals were recorded bilaterally from the flexor carpi ulnaris (FCU),biceps brachii (BB),triceps brachii (TB) and deltoid (D) during maximum isometric voluntary contractions involving wrist flexion and extension,elbow flexion and extension,and shoulder abduction.The two groups' co-contraction ratios (CR) and co-activation ratios were calculated and compared.Results During elbow flexion and extension the average CR of the BB on the affected side was significantly higher than that on the unaffected side and also significantly higher than the control group average.The average CR of the TB on the affected side was significantly higher than that of the healthy controls.In all cases the average CR of the BB was larger than that of the TB.The difference in CR between the TB and the BB on the affected side was significantly larger than on the unaffected side and the control group average.During elbow flexion,the co-activation ratio of the FCU,TB and D on the affected side was significantly higher than on the unaffected side and among the healthy controls,and the co-activation ratio of the FCU on the affected side was significantly higher than that of the D and TB.During elbow extension,the co-activation ratio of the FCU,BB and D on the affected side was significantly higher in the same way,and the co-activation ratio of the FCU on the affected side was again significantly higher than that of the D and BB.During wrist flexion,the average co-activation ratio of the BB and D on the affected side was significantly greater than that on the unaffected side and among the healthy controls,and the co-activation ratio of the BB on the affected side was significantly higher than that of the D and TB.During shoulder abduction,the co-activation ratio of the BB on the affected side was significantly larger than on the unaffected side and among the healthy controls.Conclusion After a stroke the upper limbs often show flexor spasticity and abnormal synergy patterns.Rehabilitation strategy should be adopted to tackle these so as to enhance overall limb coordination.