Surface Electromyography Analysis Of Main Muscles In Main Lower Limb Muscles During Walking Gait For Patients With Knee Osteoarthritis

Methods: 16 patients with knee osteoarthritis(KOA)and 10 healthy people without KOA were used as subjects.And the surface electromyography(sEMG)was used to measure and analyze the activation characteristics of the main muscles of the lower limb,including gluteus medius(GM),biceps femoris(BF),rectus femoris(RF),vastus medial(VM),vastus lateralis(VL),gastrocnemius(GA)and tibialis anterior(TA)during normal walking,to observe the effects of KOA on the activation level and synergistic activation in attempt to guide the clinical therapy and rehabilitation of KOA.Results:(1)It was found that the root mean square(RMS)and integral EMG(iEMG)of vastus lateralis and rectus femoris were the largest,while RMS and iEMG from gluteus medius and gastrocnemius were maximal for patients with KOA during the support phase of walking.(2)RMS of biceps femoris,tibialis anterior and gastrocnemius,iEMG of gastrocnemius,and the contribution rate of the tibialis anterior and gastrocnemius in patients with KOA were significantly lower than that of healthy people without KOA(p<0.05)during the support phase of walking.Conversely,RMS of vastus lateralis and rectus femoris,medial,iEMG of vastus lateralis and rectus femoris,the contribution rate of the rectus femoris,and co-activation ratio of the knee joint in patients with KOA were significantly higher than that of healthy people(p<0.05).(3)Activation time of vastus medial,vastus lateralis,rectus femoris,and tibialis anterior,and vastus lateralis-biceps femoris(VL-BF)and medial femoral-femoral muscles(VM-BF)co-contraction index in the patients with KOa were significantly higher than that of healthy people(p<0.05).Conclusions:(1)In terms of activation order,patients with KOA activated earlier the biceps femoris,while vastus medial and vastus lateralis were activated later.In terms of total activation time,patients with KOA increased the activation time of vastus medial,vastus lateralis,rectus femoris and tibia anterior compared with healthy people,especially rectus femoris and tibia anterior.(2)In terms of activation level,vastus medial,vastus lateralis and rectus femoris were significantly activated by patients with KOA,especially rectus femoris;on the other hand,biceps femoris,tibialis anterior and gastrocnemius were significantly less activated,especially gastrocnemius,which indicated that patients with KOA mainly relied on the activation of vastus medial and vastus lateralis to do work during the support phase of walking.(3)In terms of synergistic activation,patients with KOA selectively activated vastus medial and vastus lateralis relative to biceps femoris and gastrocnemius compared with healthy people,which could be the results of unbalancing walking gait related to the pain from patients with KOA.Suggestions:(1)It was suggested that biceps femoris with early activation should be appropriately release;at the same time,vastus medial and vastus lateralis should be early activated.The activation time of rectus femoris and tibialis anterior should be shorten in order to prevent the fatiguing state caused by long time walking,given the lengthen activation time.The therapy for rectus femoris and tibialis anterior should pay attention to the improvement of these muscles' fatiguing state.(2)The tension of the muscles accomplished knee extension should be released,especially rectus femoris.The methods such as isokinetic contraction trining should be applied to improve the recruitment level of neural systemon biceps femoris,tibialis anterior and gastrocnemius,especially gastrocnemius.(3)In addition to improve the pain of the affected limb,it was suggested to selectively improve those muscle groups with low activation level such as biceps femorisand gastrocnemius,so that the angonist and antagonist muscles are in a synergistic activation state in order to reduce knee contact pressure and related symptoms.