title: Prediction of Cervical Spinal Joint Loading and Secondary Motion Using a Musculoskeletal Multibody Dynamics Model Via Force-Dependent Kinematics Approach.
abstract: METHODS
  A cervical spine biomechanical investigation using multibody dynamics.
  
  
  OBJECTIVE
  To develop a comprehensive cervical spine multibody dynamics model incorporated with the force-dependent kinematics (FDK) approach, and to study the influence of soft tissue deformation on the joint loading prediction.
  
  
  BACKGROUND
  Musculoskeletal multibody dynamics models have been widely used to analyze joint loading. Current cervical spine musculoskeletal models, however, neglect the joint internal motion caused by soft tissue deformation. A novel FDK approach is introduced, which can predict joint internal motion and spinal joint loading simultaneously.
  
  
  METHODS
  A comprehensive cervical spine musculoskeletal model with the posterior facet joints and essential ligaments was developed. To quantify the influence of soft tissue structures on joint loading prediction, four different models with different features were created. These newly developed models were validated, under flexion-extension movement. The predicted intervertebral disc loads (from C3-C4 to C5-C6) were compared with the published cadaveric experimental results. Moreover, the predicted facet joint forces, ligament forces, and anterior-posterior translations of instantaneous centers of rotation were also studied.
  
  
  RESULTS
  The obtained intervertebral disc loads were varied among different models. Model 3 provided the closest prediction of joint loading to the experimental results. Moreover, the facet joint and ligament forces were in similar range of magnitude as literature findings. The predicted instantaneous centers of rotation translational changes were in accordance with the in vivo kinematics observation.
  
  
  CONCLUSIONS
  In the present study, a validated cervical spine musculoskeletal model was developed, using multibody dynamics and FDK approach. It can simulate the function of musculature and consider joint internal motion, and thus provides more reliable joint loading prediction. This newly developed cervical model can be used as an efficient tool to study the biomechanical behaviors of human cervical spine, and to understand the fundamental pathologies of spinal pains.
  
  
  METHODS
  N /A.
authors.affiliation: State Key Laboratory for Manufacturing Systems Engineering, School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Diao
authors.affiliation: State Key Laboratory for Manufacturing Systems Engineering, School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Xin
authors.affiliation: Department of Orthopaedics, Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Dong
authors.affiliation: Department of Orthopaedics, Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China.
authors.forename: Xijing
authors.initials: X
authors.lastname: He
authors.affiliation: State Key Laboratory for Manufacturing Systems Engineering, School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, China.
authors.forename: Dichen
authors.initials: D
authors.lastname: Li
authors.affiliation: State Key Laboratory for Manufacturing Systems Engineering, School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, China.|Institute of Medical and Biological Engineering, School of Mechanical Engineering, University of Leeds, Leeds, UK.
authors.forename: Zhongmin
authors.initials: Z
authors.lastname: Jin
mesh_terms: D001696:Biomechanical Phenomena / Q000502:physiology; D002102:Cadaver; D002574:Cervical Vertebrae / Q000502:physiology*; D006801:Humans; D007403:Intervertebral Disc / Q000502:physiology*; D008954:Models, Biological; D016059:Range of Motion, Articular / Q000502:physiology*; D012399:Rotation; D021801:Zygapophyseal Joint / Q000502:physiology*