Effects Of Neuromuscular Electrical Stimulation On Muscle Strength After Anteriorcruciate Ligament Reconstruction

Purpose Following anterior cruciate ligament(ACL) reconstruction, restricted weight bearing and immobilization results in thigh and calf muscle atrophy and weakness. The purpose of this study was to assess the effect of electrical muscle stimulation(NMES) on prevention of muscle atrophy in patients during the early rehabilitation stage after ACL reconstruction. Methods 31 malepatients with acute ACL tears were divided into two groups randomly. The control group participated in only the general rehabilitation program. In addition to this protocol, the electricalmuscle stimulation group received neuromuscular electrical stimulation(NMES)training using the wave form of 20 Hz exponential pulse from the 4th post-operative day to 8 weeks after the surgery. During the testing subjects were placed in standard measurement position for measuring two heads of hamstring muscle(biceps femoris – BF, semitendinosus–ST). Each muscle was transcutaneous twitch stimulated via two bipolar placed electrodes on the skin surface above the muscle head. Supramaximal muscle response was than recorded using TMG method and stored on PC for further analysis. From each response the maximal amplitude(Dm) was calculated and compared to healthy lateral side. The lateral symmetry coefficient of the each muscle was calculated, as division of Dm on the injured and healthy side. Results1) No significant differences were found between the subjects’ physical characteristics. P >0.05.2) Before operation,there is no significant differences were found between the subjects’ Dm symmetry. P >0.05.3) Subjects from both groups significantly increased the amount of treatment activity achieved after the 8-week training period. P <0.05.4)Both BF and ST’s result show the NMES group performed at a significantly greater level than the control group. P <0.05.Muscle thickness of hamstring increased significantly 8 weeks after surgery in the NMES group, and it also increased significantly in the control group. The NMES group showed greater recovery of knee flexion strength after 8 weeks after surgery. ConclusionNMES implemented during the early rehabilitation stage is effective in maintaining and increasing muscle thickness and strength in the operated limb.