Effects Of Blood Flow Restriction Combined With Low Intensity Resistance Exercise On Lower Limb Function And Surface Electromyography Time Domain Indexes In Patients With Stroke

ObjectiveTo investigate the effects of blood flow restriction training combined with low intensity resistance exercise on lower limb muscle strength,function,average surface EMG（AEMG）,root mean square value（RMS）and integral EMG（IEMG）in stroke patients.MethodFifty eight stroke patients were randomly divided into the experimental group and the control group.Both groups received routine rehabilitation training and Motomed intelligent treadmill exercise under 20% one repetition maximum（1RM）resistance.On this basis,the experimental group tied the pressure cuff to the middle and upper thigh（10 cm from the upper edge of patella）,pressed it to 200 mm Hg,pressed it for 3 min,and relaxed it for 1 min,repeat 5 groups,a total of 20 min,from Monday to Saturday in the morning and afternoon,continued treatment for 2 weeks.Before treatment and 2weeks after treatment,the training effect of patients in each group was evaluated.The lower extremity function was evaluated by using lower extremity Fugl-Meyer score and recording the change value of 20% 1RM pedaling resistance before and after treatment.The changes of peak torque（PT）,peak torque/body weight ratio（PT/W）,total work（TW）,and peak torque ratio（H/Q）of flexor/extensor muscles of knee joint were evaluated by isokinetic muscle strength test system.The changes of AEMG,RMS and IEMG of rectus femoris,biceps femoris,tibialis anterior muscle and gastrocnemius muscle of the affected side were measured by surface EMG.Result（1）Changes of lower extremity function: After 2 weeks of treatment,lower extremity function of both groups improved significantly.The Fugl-Meyer score and resistance change of lower extremity in the two groups were significantly increased after treatment than before treatment（P<0.01）.Comparison between the two groups after treatment showed no statistical significance（P>0.05）,although the scores of the experimental group were higher than that of the control group.（2）Changes of knee joint muscle strength: After 2 weeks of treatment,the stretching and flexion muscle strength of the experimental group and the control group were improved,the increase of PT,PT/W,TW,H/Q ratio of the experimental group was better than that of the control group（P<0.05）,but the flexion PT,PT/W,TW had no significant changes（P>0.05）.（3）Changes of surface EMG time domain indexes: After 2 weeks of treatment,the amplitudes of AEMG,RMS,and IEMG of the main muscle groups of lower limbs on the affected side of patients in both groups were significantly increased,while the amplitudes of AEMG,RMS,and IEMG on the healthy side had little change（P>0.05）.After treatment,the amplitudes of AEMG in the rectus femoris of the experimental group increased more than that of the control group（P<0.05）.Compared with the control group,the RMS and IEMG values of rectus femoris,biceps femoris,gastrocnemius of the affected side of the experimental group were significantly changed（P<0.05）.There was no difference in RMS and IEMG of tibialis anterior muscle between the two groups（P>0.05）.ConclusionBFR-LI can improve the lower limb function of stroke patients in the short term,improve the muscle strength and muscle fiber recruitment ability of the restricted parts,and significantly improve the muscle that can be trained in the unrestricted parts,especially the activation and muscle strength growth of the original muscle.