Opensim-based Biomechanical Analysis Of Lumabar Musculoskeletal System

It's estimated that about 80% of all people have back pain at some time in life,despite the pathogenesis of back pain is complex,it has been posited to originate mostly from biomechanical properties of lumbar muscles or vertebras.An enhanced lumbar musculoskeletal model was set up based on Opensim platform,which can be used to simulate different postures and movements of body,and it provides an inexpensive and efficient methods to determine the intervertebral force and muscle force.Existing musculoskeletal model was improved via modifying constrains of 5 lumbar vertebras,adding stiffness matrixes which represent intervertebral soft tissues,modeling intra-abdominal pressure with transve rsus and equivalent concentrated forces,correcting parameters of muscle based on Thelen's muscle-tendon model.A multi-body musculoskeletal model with nine lumbar muscle groups was set up eventually.Based on single variable rule,q uantitative analysis was conducted of each parameters of muscle-tendon model,and effect of stiffness matrix was considered to adjust values to different postures of motions.What's more,validation of musculoskeletal model shows substantial correlation to the existing literatures.A new musculoskeletal model was used to analyze the muscle force of different postures and motions during flexion,extension,lateral bending and axial rotation,while effects of aging,acceleration,initial abdominal pressure and motion of arms are concerned.Computations indicate that aging of muscles will influence activation instead of the distribution of muscle forces,motion of arms will affect some muscle groups,acceleratio n will enhance the force of muscles which are mainly exerting strength,and abdominal pressure is a factor that will affect muscle forces rather than their change rules.O verall simulation results were basically consistent with the kinesiology of musculoskeletal.This model effectively analyzed the biomechanics of lumbar spine and muscles,certainly it shows a brilliant application prospect in research and development of orthopedic medical devices and rehabilitations with further study.