The Effects Of The Lumbar Segmental Stability On The Morphology And Functional Characteristics And Coordination Pattern Of Trunk Muscles In People

Purpose:The people with nonspecific low back pain (NLBP) accounts for85%of all low back painpatients. Compared with diseases, NLBP is more like the general term of a group of symptoms, the causes of which may be different from each other. The lumbar segmental instability (LSI) is regarded as one important subgroup of NLBP. As the most important stabilizationsystem of spinal column, trunk muscles must be closely connected to the lumbar spinal stability. The research purpose of this thesis is making a comparison between the differences of various lumbar segmental stabilities in respects of morphology, myotonometric, strength or coordination patterns of trunk muscle group and finding out whether relevant factors have any effects on such differences or not.Methods:In this thesis, the test objects are male during the age of18to40. The NLBP Subgroup with different lumbar spinal stability (10people in LSI Group,9people in Non-LSI Group) and the Normal Control Group (10people in Control Group) shall be established. By means of relevant tests, the morphology of paraspinal muscle, tension data as well as the maximal muscle force of different muscle groups in spinal column are collected. The surface electromyography (SEMG) of trunk muscle group is recorded in the isometric and isotonic tests. Furthermore, the strength of spinal muscles and movement angle of spinal column are recorded. By performing MANOVA, the thesis compares different groups as well as the effects of various factors exerted on the morphology of paraspinal muscle (group, lumbar level), tension and isometric coordination patterns of trunk muscles.Results:there is no interaction between group factors and other factors in this research. There is no significant difference of multifidus muscle’s size and shape in factors such as group, lumbar level and right or left sides. Except for theeffect of its own contractionstate, the tension property has no difference in different groups and zygomorphy. For the flexionandextensionof spinal muscles and the maximum strength of cyclotron, it shows that along with the initial length of power musclesincreases due to the position change, the strength increases. For between-group differences, the flexor muscle strength of two NLBP groups is greater than that of Control group, but the extensor strength of two NLBP groups is smaller. The flexor and extensor torque ratio of LSI group is bigger than that of Control group (p<0.05). There is no related difference or tendency in left and right cyclotron. In the isometric force in each operation were present in all strongly positions the agonist activation level with forced degree of improvement and increased significantly change, the antagonist also showed this trend; differences between groups mainly force for each direction of the LSI group antagonistic muscles was significantly higher than Non-LSI group or Control group. In isotonic movement, flexion, lateral flexion and swing action with body position farther away from the middle position and activates the higher the level, turn the ring of muscle action initiative also activate their specific intervals, the difference in this direction is more extensor group obvious. The group differences were mainly in thecoactivation levels and other indicators of LSI group was significantly higher than Non-LSI group.Conclusion:In this study, low back pain and lumbar stability factor does not affect the shape and physical characteristics of the trunk muscles, inferring that the basic characteristics of the trunk muscles are not directly associated with NLBP and the LSI. Low back pain and lumbar instability affecting mainly the trunk muscles for functional characteristics are:abdominal and back muscle strength in NLBP is unbalanced, relatively weak back muscles; NLBP patients with LSI always exhibit higher antagonistic muscle activation level or more active muscle synchronization, indicating that changes in lumbar segmental stability will cause changes in muscle work patterns. Compared with the basic characteristics,the relationship between functional characteristics changes and NLBP is more closely. LSI group relative to Non-LSI group showed greater trunk flexion strength imbalances and a higher level of activation in the trunk muscle performance characteristics, indicating that NLBP is not a homogenous group, and subgroup division is feasible and necessary in further studies.