- Email: [email protected]
Model of human spine system
Abstracts-International
Society of Biomechanics
XII Congress 1989
1003
INTRASUKDXT VARIARILITY IN LOWER EXTREMITY JOINT MOMENTS OF FORCE DURING THE SUPPORT PHASE OF RUNNING Paul DeVita & William A. Skelly, PE Dept., Southern Illinois Univ., Carbondale, 111, USA Researchers have reported lower extremity joint moments of force (JMF) along with meafew estimates of intrasubject variability (ISV) sures of intersubject variability. However, The purpose of this study was to quantify ISV in lower in JMF patterns have been reported. Experimental setup consisted of a force extremity JMFs during the support phase of running. .2 m/s) & a 16mm camera to film the platform, timing system to monitor running speed (4.3 +/Testing protocol consisted of 4 test sessions of 10 trials runners in the sagittal plane. 2 & 8 to provide for within test session (cl) each per subject: days 1 (morning & afternoon), An inverse dynamics approach com& day (~2) and between day (~3) & week (~4) ISV estimates. bining film, force plate & subject anthropometric data was used to derive JMFs. ISV was evaluated with coefficients of variation (CV) & a single subject statistical technique The CVs indicated that the average (p<.OS) to identify specific differences between sessions. normalized standard deviation among JMF curves increased over that of a single test session but was constant over longer time periods (hip CVs for cl=37%, c2-c4=40%). The ISV CVs were analysis showed an about 50% of previously reported intersubject CVs. The statistical increasing number of significant comparisons from c2 to c4 (c2=21%, c3=32%, c4=36%). However, most absolute differences between means (MAD) did not increase past c3. The results of both analyses indicated that ISV of lower extremity JMFs was best estimated with CVs from 2 comknee & ankle CV=22%) and that aver:.ge bined sets of trials obtained 1 day apart (hip CV=40%, knee & ankle maximum extensor moments must be MADs of 0.45, 0.33 & 0.26 Nm/kg for hip, attributed to normal subject performance variability.
MODEL OF HUMAN SPINE SYSTEM M. Dietrich, K. Kedzior, T. Zagrajek Warsaw University of Technology, Insititute for Aircraft Engineering and Applied Mechanics, ul. Nowowiejska 22/24,00-665 Warsaw, Poland Two-stage way of modeling of human spine system is proposed. In stage one, a general but simplified Finite Element Method model of the whole system is considered. It serves to determine those forces and dislocations, in principal nods of the system, which are due to external loads. In stage two, the chosen subsystem is considered in detail. The general model consists of the following sets: 24 vertebrae, each vertebra consists of 34 rigid finite elements; 23 intevertebml disks, nucleus pulposus of each disk is modeled with 18 incompressible elements and anulus fibrosus consists of 16 anisotropic elastic elements; ligaments which are modeled with 400 anisotropic elements connected by 34 flexible elements modeling cartilage; fragments of head, scapula and pelvis composed of 50 rigid elements; muscles modeled with 600 anisotropic, elastic elements which contract (when stimulated) along muscle fibres. Limitations of the relative movement of ribs and vertebrae are introduced in the model in the form of kinematic dependences. The model has been loaded with the body weight and a weight and a weight held in hands. Both loads have been substituted with a concentrated forces system applied to finite element nods (-20000 nods). Results obtained with help of computer simulation (12892 nonlinear equations) proved the usefulness of the model.
THE MEASUREMENT AND ANALYSIS OF SHAKING STATES Ding Jiangxin and Dai Youling Hubei Science Institute of Snorts Wuhan, Hubei P.R. ChinaWhen the body keeps shaking in a vertical position it is in the category of a random vibration system. The movement is not only decided bv the random excitation but related to the inherent nrouerties of the bodv. such as those concerningVthe vestibuiar function, the visual system, and the coefficieniof *me shape. Body d shaking states vary from person to person. This paper studies a body shaking state measuring device composed of a high precision crystal rate gyroscope and a TP-801 single board computer. It has provided a new approach for the study of balance barriers. It is, without doubt, of great significance for the selection and training of athletes. Also, in me light of discrete time sequences and spectral analysis, the paper studies and analyzes the results of Romberg’s and Man’s experiments on body shaking, focusing on the comparison of data obtained when eyes are open with those obtained when eyes are closed. This is quite helpful for the study of balance and adjustment functions.
Society of Biomechanics
XII Congress 1989
1003
INTRASUKDXT VARIARILITY IN LOWER EXTREMITY JOINT MOMENTS OF FORCE DURING THE SUPPORT PHASE OF RUNNING Paul DeVita & William A. Skelly, PE Dept., Southern Illinois Univ., Carbondale, 111, USA Researchers have reported lower extremity joint moments of force (JMF) along with meafew estimates of intrasubject variability (ISV) sures of intersubject variability. However, The purpose of this study was to quantify ISV in lower in JMF patterns have been reported. Experimental setup consisted of a force extremity JMFs during the support phase of running. .2 m/s) & a 16mm camera to film the platform, timing system to monitor running speed (4.3 +/Testing protocol consisted of 4 test sessions of 10 trials runners in the sagittal plane. 2 & 8 to provide for within test session (cl) each per subject: days 1 (morning & afternoon), An inverse dynamics approach com& day (~2) and between day (~3) & week (~4) ISV estimates. bining film, force plate & subject anthropometric data was used to derive JMFs. ISV was evaluated with coefficients of variation (CV) & a single subject statistical technique The CVs indicated that the average (p<.OS) to identify specific differences between sessions. normalized standard deviation among JMF curves increased over that of a single test session but was constant over longer time periods (hip CVs for cl=37%, c2-c4=40%). The ISV CVs were analysis showed an about 50% of previously reported intersubject CVs. The statistical increasing number of significant comparisons from c2 to c4 (c2=21%, c3=32%, c4=36%). However, most absolute differences between means (MAD) did not increase past c3. The results of both analyses indicated that ISV of lower extremity JMFs was best estimated with CVs from 2 comknee & ankle CV=22%) and that aver:.ge bined sets of trials obtained 1 day apart (hip CV=40%, knee & ankle maximum extensor moments must be MADs of 0.45, 0.33 & 0.26 Nm/kg for hip, attributed to normal subject performance variability.
MODEL OF HUMAN SPINE SYSTEM M. Dietrich, K. Kedzior, T. Zagrajek Warsaw University of Technology, Insititute for Aircraft Engineering and Applied Mechanics, ul. Nowowiejska 22/24,00-665 Warsaw, Poland Two-stage way of modeling of human spine system is proposed. In stage one, a general but simplified Finite Element Method model of the whole system is considered. It serves to determine those forces and dislocations, in principal nods of the system, which are due to external loads. In stage two, the chosen subsystem is considered in detail. The general model consists of the following sets: 24 vertebrae, each vertebra consists of 34 rigid finite elements; 23 intevertebml disks, nucleus pulposus of each disk is modeled with 18 incompressible elements and anulus fibrosus consists of 16 anisotropic elastic elements; ligaments which are modeled with 400 anisotropic elements connected by 34 flexible elements modeling cartilage; fragments of head, scapula and pelvis composed of 50 rigid elements; muscles modeled with 600 anisotropic, elastic elements which contract (when stimulated) along muscle fibres. Limitations of the relative movement of ribs and vertebrae are introduced in the model in the form of kinematic dependences. The model has been loaded with the body weight and a weight and a weight held in hands. Both loads have been substituted with a concentrated forces system applied to finite element nods (-20000 nods). Results obtained with help of computer simulation (12892 nonlinear equations) proved the usefulness of the model.
THE MEASUREMENT AND ANALYSIS OF SHAKING STATES Ding Jiangxin and Dai Youling Hubei Science Institute of Snorts Wuhan, Hubei P.R. ChinaWhen the body keeps shaking in a vertical position it is in the category of a random vibration system. The movement is not only decided bv the random excitation but related to the inherent nrouerties of the bodv. such as those concerningVthe vestibuiar function, the visual system, and the coefficieniof *me shape. Body d shaking states vary from person to person. This paper studies a body shaking state measuring device composed of a high precision crystal rate gyroscope and a TP-801 single board computer. It has provided a new approach for the study of balance barriers. It is, without doubt, of great significance for the selection and training of athletes. Also, in me light of discrete time sequences and spectral analysis, the paper studies and analyzes the results of Romberg’s and Man’s experiments on body shaking, focusing on the comparison of data obtained when eyes are open with those obtained when eyes are closed. This is quite helpful for the study of balance and adjustment functions.