Characteristics of Dynamic Contractions on Surface Electromyography Single of Stroke Patients Induced from Low Limb Muscle When Exercising Passively, Exercising Initiatively with Assitant and Against Resistance / 中国康复理论与实践

ABSTRACT

@#Objective To investigate the characteristics of the dynamic contractions on the surface electromyography (sEMG) single of stroke patients induced from the low limb muscle when exercising passively, exercising initiatively with assistant and against resistance.Methods 24 stroke patients with hemiplegia and 17 normal subjects were tested with sEMG under a dynamic contractions in coxa and knee flexion and extension passively, initiatively with assistant and against resistance. The myoelectric signals were collected and processed by linear time and frequency domain method.Results The values of median frequency (MF) and mean power frequency (MPF) of stroke group were significantly lower, but the value of average EMG (AEMG) was higher ( P<0.001). The values of MF and MPF in activity side were lower than that in non-activity side ( P<0.001). The values of MF and MPF when exercising passively were higher than that when exercising with resistance ( P<0.05). The value of AEMG when exercising with resistance was highest. The values of MF and MPF in the synergist muscle were higher. The values of AEMG in the antagonistic muscle and synergist muscle were higher than that agonist and synergist muscle ( P<0.01). The values of MF and MPF in non-paretic exercising side were higher significantly, but in paretic exercising side and non-paretic silent side were lower. The values of MF and MPF in exercising side from vastus lateralis (VL) were the highest. The values of AEMG in exercising side and non-exercising side from biceps femoris (BF) were the highest. The values of MF and MPF in low limb of stroke group reduced, that in rectus femoris (RF) from paretic side was the lowest; that in BF from non-paretic side was the lowest ( P<0.01). The value of AEMG in low limb of stroke group was high significantly, especially in BF from the low limb of the non-paretic side in stroke patients. The values of AEMG in four group muscles gradually were higher following the higher exercising load, and that in the BF was the highest, and that in vastus medialis (VM) rose significantly.Conclusion The values of MF and MPF of stroke patients with hemiplegia reduce significantly, but the value of AEMG is higher. The values of MF and MPF in exercising side are lower than that in non-exercising side and non-paretic exercising side rising significantly, but that in paretic exercising side and non-paretic silent side reduce significantly. The values of MF and MPF in assistant exercise are higher than that in passive exercise and resistance exercise, but the value of AEMG in resistance exercise is higher than that in assistant exercise and in passive exercise. The values of MF and MPF in synergist muscle rise, but the values of AEMG in antagonist and synergist muscle are higher than that agonist and synergist muscle.