Surface EMG Study On Relieving Fatigue Of Lumbar Vertical Spine Muscle And Polyfidus Muscle With Trunk Motion In Point Rubbing Committee

[Objective]Using sEMG as Electrophysiology test tool and taking static endurance weight load test as the function evaluation method, this study is to test and verify the different result of alleviating the low back muscle(LBP) fatigue with different acupoint-pressing duration at Weizhong(BL40), to explore whether this new compound method of acupoint-pressing at Weizhong along with voluntary back exercise(switching face down on bed to 4 points kneeling continuously ) is more effective, efficient and ease-to-use, which can help on clinic of alleviating the low back muscle and back pain.[Method]30 healthy college male students participated in four phases of static endurance weight load test of back muscle in a row, namely the Biering-Sφrensen test(BST) in this study. BST require the subjects facing down on the bed which has a removable fore half, legs are tied on the bed, hands hold the opposite should. The fore half of the bed removed when the test is begin. The upper part of the body hangs in the air and keep horizontal all relying on the back muscle until the trunk slope downward more 10 degrees. The duration time of BST is as the assess index.The first phase(matched phase): two BSTs were taken before and after the intervention of facing down on bed for 5min. The second phase(1min-pressing phase) was one week of rest after the first one: the intervention of acuppoint-pressing at Weizhong for 1 min and 4min of facing down on bed was between the two BSTs. The third phase(5min-pressing phase) was one week of rest after the second one: the intervention of acuppoint-pressing at Weizhong for 5 minutes was between the two BSTs. The fourth phase(P&M phase) was one week of rest after the third one: the intervention of 2 minutes acuppoint-pressing along with voluntary back exercise(switching face down on bed to 4 points kneeling continuously ) and 4min of facing down on bed was between the two BSTs. Subjects were required to maintain normal life during the study and forbidden to take aggravating activities like long-distance race. They were asked to avoid getting hurts on back or leg. 3 subjects were rejected, including 1 case of long-distance race, 1 case of getting hurt on back, 1 case of back pain after test. Date of 27 subjects were collected in this study.Index: the durance time of two BSTs of every phase, the mean power frequency(MPF)and median frequency(MF)of sEMG of bilateral lumber erector spinae and the multifidus.[Result]1 Time of BSTThe difference between two BST of every phase was significant(P<0.05) in matched phase, 1min-pressing phase, and 5 min-pressing phase. The P&M phase was insignificant(P>0.05). Multiple comparison of time of first BST among phases: the difference was insignificant(P>0.05) in every comparison. Multiple comparison of time of second BST among phases: the difference was insignificant(P> 0.05) between matched phase and 1 min-pressing phase. The rest comparisons were significant(P<0.05).2 MF and MPF of bilateral lumber erector spinaes and the multifidusAll four muscles were different(P<0.05) in matched group. only left erector spinaes was indifferent (P>0.05) in 1 min-pressing phase, the rest three muscles were different(P<0.05).Only right multifidus was indifferent(P > 0.05) in 5 min-pressing phase. The rest were indifferent(P<0.05).All muscles were indfferent(P>0.05) in P&M phase.Multiple comparison among phases of MF and MPF of first BST: the difference was insignificant(P>0.05) in every case.Multiple comparison among phases of MF and MPF of second BST: both matched phase and 1 min-pressing phase were different(P<0.05) from P&M phase on bilateral lumber erector spinaes and multifidus, the rest comparisons were indifferent(P>0.05). the matched group was different(P<0.05) from the 5 min-pressing phase on the bilateral multifidus.[conclusion]1 Acupoint-pressing at Weizhong can the low back muscle fatigue effectively.2 Duration of acupoint-pressing at Weizhong(BL40) has a positive dose-effect relationship with alleviating the low back muscle. Bilateral lumber erector spinae and the multifidus fatigue alleviate with a timing difference.3 The compound method of acupoint-pressing at Weizhong along with voluntary back exercise which needs switching lie face downward to Four Points Kneeling continuously can alleviating the low back muscle fatigue in a short time(2min) . This method is more effective and efficient than just acupoint-pressing.