A comprehensive, geometrically accurate, nonlinear C0-T1 three-dimensional finite element (FE) model was developed for the biomechanical study of human cervical spine and related disorders. The model was developed with anatomic detail from the computed tomography (CT) images of a 46-year-old female healthy volunteer, and applied the finite element model processing softwares such as MIMICS13.1, Hypermesh11.0, Abaqus 6.12-1, etc., for developing, preprocessing, calculating and analysing sequentially. The stress concentration region and the range of motion (ROM) of each vertebral level under axial rotation, flexion, extension, and lateral bending under physiologic static loadings were observed and recorded. The model was proven reliable, which was validated with the range of motion in previous published literatures. The model predicted the front and side parts of the foramen magnum and contralateral pedicle and facet was the stress concentration region under physiological loads of the upper spine and the lower spine, respectively. The development of this comprehensive, geometrically accurate, nonlinear cervical spine FE model could provide an ideal platform for theoretical biomechanical study of human cervical spine and related disorders.
Biomechanical Phenomena ; Cervical Vertebrae ; Female ; Finite Element Analysis ; Humans ; Middle Aged ; Models, Biological ; Range of Motion, Articular ; Rotation

Objective To analyze the current situation and influence factors of ordinary medical college undergraduates' contact with scientific research at early stage in order to provide references for scientific research.Methods Totally 1940 students majoring in clinical medicine,imaging,traditional Chinese medicine and nursing (2008 -2010 grade) in China Three Gorges University were enrolled to do questionnaine and SPSS 17.0 was used to do statistical analysis.Results Totally 1653copies of questionnaires were collected from 1940 students,the recovery rate was 85.21％.Two hundred and nineteen students ( 13.25％ ) participated in scientific research,65.28％ students thought college propaganda to be ordinary,95.43％ students got benefits from scientific research.The main influence factors of scientific research were lack of time (23.73％),insufficient knowledge reserves (22.03％) and researchers' own problems (39.73％).Conclusions Medical school should expand the range of scientific research and strengthen propaganda.Medical students should arrange research time and constantly improve their comprehensive ability so as to achieve good results.

Background:Understanding and minimizing existing global coronavirus disease 2019(COVID-19)vaccination disparities is critical to global population health and eliminating health inequities.The study aims to investigate the disparities of vaccination coverage and progression and the associated economic and educational determinants to inform global COVID-19 vaccination strategies.Methods:COVID-19 vaccination coverage data from 206 countries used in the study were derived from"Our World in Data"website.After obtaining the vaccination coverage indicators,we fitted the progression indicators for vaccination.Correlation and multiple linear regression analysis were used to examine the effects of gross domestic product(GDP)per capita,Gini index,education,and their interactions on the coverage and progression of the COVID-19 vaccination.Results:The coverage of COVID-19 vaccination ranged from less than 30 doses to more than 150 doses per hun-dred people,from less than 15％to more than 75％for proportion of people vaccinated,from less than 15％to more than 60％for proportion of people fully vaccinated.Similarly,the progression of vaccination ranged from less than 0.1 to more than 0.6 for progression of total number of doses,from less than 0.1 to more than 0.3 for progression of proportion of people vaccinated,and from less than 0.1 to more than 0.4 for progression of propor-tion of people fully vaccinated.GDP per capita and education were positively associated with the coverage and progression,while Gini index was negatively associated with the coverage and progression.Negative interaction between GDP per capita and education was also observed for coverage(β=-0.012 to-0.011,P＜0.05)and progression(β=-0.012 to-0.011,P＜0.05).Conclusions:Substantial geographic disparities existed for the coverage and progression of COVID-19 vaccination.Economy and education are two important factors contributing to the disparities.Different countries may adopt varied strategies to promote the national distribution and vaccination of COVID-19 vaccines.

Objective:To explore the relationship between school bullying and mental sub-health in middle school students and the potential moderating role of resilience in this relationship.Methods:Totally 792 students aged 10 to 14 years from two middle schools in Wuhan were selected.The Chinese version of Olweus Bully/Victim Questionnaire,Multidimensional Sub-health Questionnaire of Adolescents,and Adolescent Psychological Resilience Scale were used to measure school bullying,mental sub-health,and psychological resilience of students,respectively.Results:Being bullied scores were positively associated with mental sub-health scores(β=1.88).The moderating effect of psychological resilience scores between being the scores of bullied and mental sub-health was statistically significant(β=-0.07).Conclusion:The experience of bullying may be associated with mental sub-health problems of middle school students,and psychological resilience may play a moderating role in the relation-ship between being bullied and mental sub-health.

Clinical advantages of Chinese spinal manipulation therapy (CSMT) were recognized for spinal chronic lesions of soft tissues and bones, such as cervical spondylosis, etc. However, the security of CSMT and the hypotheses of practice mechanisms were questioned for lacking of the relevant basic researches. Researches have proved that these methods could be used to observe the dynamic effects of spine with application of finite element analysis (FEA) computer technology. Combining with other biomechanical experimental methods and applying advanced FEA technology for mechanical problems of CSMT, we may not only find the mechanisms of action and provide theoretical supports for the traditional Chinese therapy, but also standardize the key techniques and optimize the treatment options improving clinical outcomes, and even promote spreading of CSMT. Computer models are ideally suited for studying phenomena that cannot be satisfactorily investigated with other models. However, computer models of CSMT practice remain to be further refined. The results which had been acquired so far not only verified some of the traditional points of view, but also revised and specified some perspectives of the past. This paper intends to review FEA studies with Chinese cervical manipulation therapy (CCMT) for cervical spinal chronic lesions of soft tissues and bones, involving different effects for cervical spine joints (pulling/traction and thrusting) with practice techniques and cervical spine soft tissues (including vessels and its hemodynamics, muscles and fasciae, etc).
Biomechanical Phenomena ; Cervical Vertebrae ; anatomy & histology ; physiopathology ; Finite Element Analysis ; Humans ; Manipulation, Spinal ; methods ; Spondylosis ; physiopathology ; therapy

Objective To simultaneously collect and analyze the kinematic and dynamic parameters for two techniques of traditional Chinese cervical manipulation ( TCCM), and quantitatively describe its biomechanical characteristics. Methods A senior practitioner completed the TCCM (positioning and directional rotation pulling, lateral flexion, respectively) on 10 healthy subjects, and the fluorescent marker balls were pasted on the operator to capture manipulation movements. The dynamic parameters and the surface electromyography ( sEMG) signals were collected by pressure-sensitive gloves and wireless sEMG acquisition system. Results The upper arm muscle was the main force muscle during TCCM, and biceps brachii had the highest contribution rate. The range of motion (ROM), speed, pulling force, and time during cervical spine positioning and directional rotation pulling were all greater than those during cervical spine lateral flexion. The integrate electromyography ( iEMG) and root mean square (RMS) for each muscle of the operator during cervical spine positioning and directional rotation pulling were higher than those during cervical spine lateral flexion. Conclusions The overall ROM, three-dimensional (3D) motion angle, load intensity and time during CCTM have the characteristics of high speed, low amplitude and strong force, reflecting the biomechanical characteristics of ‘ cunjin ’ ( one-inch punch ) in traditional Chinese medicine. This study provides references for further standardizing manual teaching and training and improving clinical safety.