Analysis and modeling of human seat interaction with a focus on the upper body and backrest using biomechanics and contact mechanics

Work ◽  
2021 ◽  
Vol 68 (s1) ◽  
pp. S161-S182
Author(s):  
Yuezhi (Sean) Liu ◽  
Xianzhi Zhong ◽  
Wintta Ghebreiyesus ◽  
Jiancheng Ji ◽  
Fengfeng (Jeff) Xi
Keyword(s):  
Human Body ◽  
The Body ◽  
Contact Forces ◽  
Human Anatomy ◽  
Upper Body ◽  
Stress Theory ◽  
Body Segments ◽  
Seat Comfort ◽  
Muscular Structure ◽  
Point Forces

BACKGROUND: This paper outlines a method to study the interaction between the human body and the aircraft seat concerning the seat comfort. METHOD: Firstly, the human body is modeled based on biomechanics and divided into a number of body segments connected by joints according to human anatomy. The angles between the body segments are obtained by curve fitting of the existing biomechanical research data. The contact forces between the human body and the seat are modeled using pairs of bi-lateral point forces. These forces are calculated and located through the analysis of the center of gravity of each body segment and average muscular structure of the human body. The geometry of the human and the seat is obtained from a 3D scan model or a CAD model. Secondly, the pressure distribution between the human body and the seat is modeled and calculated using the contact stress theory. The results of the two parts are combined to analyze the comfortability in relation to different postures, backrest recline angles and changing in shape and material. RESULTS: Simulations were performed and they are compared with experimental measurement and various FEM studies for validation. It is found that accuracy of this method is comparable with most FEM calculation. CONCLUSION: This method provides a new direction in cushion conform research. It is faster and convenient to use comparing to the FEM, and the result is reliable.

Biodynamic Characteristics of Upper Limb Reaching Movements of the Seated Human Under Whole-Body Vibration

2013 ◽  
Vol 29 (1) ◽  
pp. 12-22 ◽  
Author(s):  
Heon-Jeong Kim ◽  
Bernard J. Martin
Keyword(s):  
Right Hemisphere ◽  
Whole Body Vibration ◽  
The Body ◽  
Upper Body ◽  
Whole Body ◽  
Vibration Transmission ◽  
Body Vibration ◽  
Body Segments ◽  
Human Movements ◽  
Reach Movements

Simulation of human movements is an essential component for proactive ergonomic analysis and biomechanical model development (Chaffin, 2001). Most studies on reach kinematics have described human movements in a static environment, however the models derived from these studies cannot be applied to the analysis of human reach movements in vibratory environments such as in-vehicle operations. This study analyzes three-dimensional joint kinematics of the upper extremity in reach movements performed in static and specific vibratory conditions and investigates vibration transmission to shoulder, elbow, and hand along the body path during pointing tasks. Thirteen seated subjects performed reach movements to five target directions distributed in their right hemisphere. The results show similarities in the characteristics of movement patterns and reach trajectories of upper body segments for static and dynamic environments. In addition, vibration transmission through upper body segments is affected by vibration frequency, direction, and location of the target to be reached. Similarities in the pattern of movement trajectories revealed by filtering vibration-induced oscillations indicate that coordination strategy may not be drastically different in static and vibratory environments. This finding may facilitate the development of active biodynamic models to predict human performance and behavior under whole body vibration exposure.

Identification and Experimental Validation of Damping Ratios of Different Human Body Segments Through Anthropometric Vibratory Model in Standing Posture

2006 ◽  
Vol 129 (4) ◽  
pp. 566-574 ◽  
Author(s):  
T. C. Gupta
Keyword(s):  
Human Body ◽  
Damping Ratio ◽  
Physical Structure ◽  
The Body ◽  
Anthropometric Data ◽  
Body Segments ◽  
Lumped Parameter ◽  
Mass Damper ◽  
Linear Spring ◽  
Experimental Response

A 15degrees of freedom lumped parameter vibratory model of human body is developed, for vertical mode vibrations, using anthropometric data of the 50th percentile US male. The mass and stiffness of various segments are determined from the elastic modulii of bones and tissues and from the anthropometric data available, assuming the shape of all the segments is ellipsoidal. The damping ratio of each segment is estimated on the basis of the physical structure of the body in a particular posture. Damping constants of various segments are calculated from these damping ratios. The human body is modeled as a linear spring-mass-damper system. The optimal values of the damping ratios of the body segments are estimated, for the 15degrees of freedom model of the 50th percentile US male, by comparing the response of the model with the experimental response. Formulating a similar vibratory model of the 50th percentile Indian male and comparing the frequency response of the model with the experimental response of the same group of subjects validate the modeling procedure. A range of damping ratios has been considered to develop a vibratory model, which can predict the vertical harmonic response of the human body.

Body shape classification and block optimization based on space vector length

2019 ◽  
Vol 31 (1) ◽  
pp. 115-129
Author(s):  
Jie Sun ◽  
Qianyun Cai ◽  
Tao Li ◽  
Lei Du ◽  
Fengyuan Zou
Keyword(s):  
Cross Section ◽  
Human Body ◽  
Body Shape ◽  
The Body ◽  
Upper Body ◽  
Shape Classification ◽  
Content Type ◽  
Vector Length ◽  
Space Vectors ◽  
Three Body

PurposeConsidering two-dimensional features in the body shape classification system cannot fully reflect the three-dimensional (3D) morphological characteristics of human body. The purpose of this paper is to propose a 3D feature based method to characterize and classify the upper body shape of women, and then obtained the corresponding garment block and improved the fitness of clothing.Design/methodology/approachIn this study, the [TC]23D scanner was used to obtain human data, and 15 layers of cross-sections of young females’ upper body were extracted. In total, 240 space vectors were obtained with the center of the bust cross-section as the original point. By using the principal component analysis and K-means clustering analysis, the body shape classification based on the space vectors length was realized. The garment block corresponding to three body types was obtained using the 3D scanning data and the cross-section convex hull, and compared with existing garment block and evaluated fitness of the blocks.FindingsIn total, 11 main components used to characterize the 3D morphological features of young women were obtained, which could explain 95.28 percent features of young women’s upper body. By cluster analysis, the body shape of women was divided into three categories. The block of three body types was obtained by the construction of the convex hull model.Originality/valueThis paper investigates a classification method of the body shape based on space vector length, which can effectively reflect the difference of surface shape of human body and further improve the matching degree of human body and clothing.

scholarly journals XXIII. Researches into the nature of the involuntary muscular tissue of the urinary bladder

1859 ◽  
Vol 149 ◽  
pp. 469-477
Keyword(s):  
Urinary Bladder ◽  
Human Body ◽  
Royal Society ◽  
Cell Structure ◽  
The Body ◽  
Muscular Tissue ◽  
General Acceptance ◽  
Muscular Structure

During the last few years anatomists have considered the muscular substance of the bladder to be composed of elongated contractile fibre-cells, each with a nucleus in it, which possess free ends, and overlap at their pointed extremities without being united or joined together. This notion of the cell-structure originated with Professor Kölliker; and it has since received very general acceptance. From the correctness of that opinion I am led to dissent by my researches; and I purpose to show in this communication to the Royal Society, that both the involuntary muscular tissue of the bladder and the voluntary muscular substance in other parts of the human body have a like composition. In a former paper to the Society (in June 1856) I made the announcement that the views now bought forward of the muscular structure of the bladder were applicable to the involuntary muscular tissue in general; but as my declaration was received with doubt, I determine to withhold its publication until I had been able to repeat my microscopical observations. Before this time I hoped to have completed the task imposed on myself, but occupation has left me leisure enough to examine thoroughly only the muscular structure of the urinary bladder. As my idea is confirmed by the result of the second examination of that viscus, I submit this paper with greater confidence to the consideration researches into the nature of the involuntary muscular tissue in other parts of the body.

A Comparative Study of the Forces Acting on a Human Rider on a Motorcycle for Different Impact Configurations

2012 ◽  
Author(s):  
Nikhil J. Dhinagar
Keyword(s):  
Human Body ◽  
Energy Content ◽  
Head Injuries ◽  
Preventive Measure ◽  
The Body ◽  
Body Segments ◽  
Injury Criteria ◽  
Male Model ◽  
Full Face ◽  
Motorcycle Crashes

In many parts of the developing countries powered motorcycles are still a primary mode of commutation. Statistics tells us that around 15–20% of the accidents happening across different countries in the world involve motorcycle crashes. With the increased importance placed on the usage of safety helmets or full face helmets by the motorbike riders, head injuries have significantly reduced as compared to the other extremities of the human body. The different segments of the human male model considered for this research are grouped into four main categories, the head and neck, the upper extremities, the lower extremities and the trunk. The center of gravity differs for different segments of the human body as each segment has its own mass. This study aims to form a comprehensive database of the forces acting on the primary human body segments for three accident configurations. The energy content of each of these segments is calculated. The deceleration of the human body after impact of the bike with the obstacle and the distance it travels before reaching zero velocity is also computed. When coupled with the existing knowledge of the injury criteria and biomechanical tolerance limits for the body segments, this can be used in a versatile way to predict injuries that could possibly occur in a bike accident and automate vehicle dynamic controls as a preventive measure. Forces calculated acting on the various human body segments can be used to suitably develop riding protection gear for commercial purposes.

Ergonomics evaluation of equipment adjustability for Mexican-American population

2003 ◽  
Vol 3 (1) ◽  
pp. 65-80
Author(s):  
Rolando Quintana ◽  
Jose A. Alonso
Keyword(s):  
Mexican American ◽  
Design Tool ◽  
The Body ◽  
Upper Body ◽  
Body Segments ◽  
Northern Mexico ◽  
The Us ◽  
The Mean ◽  
Occupational Disorders ◽  
Mexican American Population

The effects of lack of equipment adjustability on nominal ranges of motion of upper body limbs for industrial sewing operations were studied, with a particular focus on Mexican-American males. Key upper body-segments of an industrial sewing operation were marked and analyzed using cinematography for a random pool of male workers descending from northern Mexico. Experimental results revealed that the worker's posture was affected by the adjustability of the sewing equipment, which was designed for the 5th to the 95th percentile of the US population. The awkward postures in turn affected the mean angular range of motion for the body-segments studied. As a result, there was a significant percentage of the available pool of worker's that may face occupational disorders, in spite of the fact that the equipment is adjustable, albeit from the 5th to the 95th percentile of the US population. These findings are particularly important to companies whose workforce is predominantly from populations that do not fit the US population profile. An adjustability index tool was developed as an equipment purchase/design tool that quantifies the percentage of the available pool of workers at risk of occupational disorders due to improper postures resulting from lack of adjustability. Finally, a cost framework is presented for choosing equipment that minimizes internal and external costs associated with equipment adjustability.

scholarly journals Bastidores da anatomia: da história à essência humana

2020 ◽  
Vol 4 (2) ◽  
pp. 114
Author(s):  
Isabela Pereira Almeida ◽  
Andressa Karoline Da silva Malheiro ◽  
Zara Dantas Oliveira
Keyword(s):  
Middle Ages ◽  
Human Body ◽  
The Body ◽  
Human Anatomy ◽  
Present Moment ◽  
The Arts ◽  
History Of ◽  
History Of Anatomy ◽  
Human Care ◽  
The Grotesque

INTRODUCTION: The history of Anatomy, its artistic representation and the history of the human body, with its taboos, have come a long way until the present moment. The objective of this work is to understand the historical points of this area of knowledge, as well as the subjectivity involved, correlating it with Literature and the Arts. DEVELOPMENT: The production of anatomical knowledge begins in prehistory; it is watertight in the Middle Ages; gains momentum in Oriental Medicine and reaches its peak in spectacles of public dissections. Anatomy is established as a form of entertainment through the regulation of public dissections, leading to the trivialization of death, the appreciation of the grotesque, the scarcity of corpses and the fear of misappropriation of bodies. As anatomy has grown as an area of knowledge, it has created the basis for health sciences and human care. It has emerged over time that the study of anatomical pieces requires essential principles - sensitivity, ethics and respect - and allows us to reflect on the transposition of the boundaries between the beautiful versus the grotesque; the pleasant versus the disgusting. It also allows reflection on the trivialization, commercialization and eroticization of the body, as well as on the limits of science. CONCLUSION: Human anatomy, in its multiple aspects, has come a long way and constitutes a precious source of knowledge, however, it is faced with enticement by the most different interests. It is necessary to rescue the beauty of the human body, which is an inseparable part of the being that inhabits / dwelt there in order to resignify its human essence.

scholarly journals COMPREHENSIVE STUDY ON ASTHISANKHYA SHAREERA IN RELATION TO ANATOMY

2020 ◽  
Vol 8 (10) ◽  
pp. 4801-4805
Author(s):  
Geethu Arumughan ◽  
Swapna Kumary
Keyword(s):  
Calcium Phosphate ◽  
Connective Tissue ◽  
Human Body ◽  
Blood Cells ◽  
White Blood Cells ◽  
Organic Matrix ◽  
Modern Human ◽  
The Body ◽  
Human Anatomy ◽  
Comprehensive Study

Acharya Sushruta explained that the organs of the body destroy after death except Asthi. Importance of Asthi & Sandhi is explained that it supports the human body just as trees are supported by the middle core Sara present inside the trunk. Knowledge of Asthi can be traced back from the Vedas passing chronologi-cally down to Samhitas. Bones are the hard-connective tissue forming the substance of the skeleton of most vertebrates, composed of a collagen rich organic matrix impregnated with calcium, phosphate, and other minerals. Bones protect the various organs of the body, produce red and white blood cells, store minerals, provide structure and support for the body and enable mobility. Importance of knowledge of Shareera Sankhya is given in our Samhitas. It explained that the clinician who has knowledge about hu-man body with its all parts with their enumeration never gets distracted. There is different opinion regarding the number of Asthi in different Samhitas. According to Acharya Charaka and Vagbhata 360 bones are present in Shareera. 300 bones are present in the Shareera according to Sushruta. The adult human body has 206 bones as per modern anatomy. Here is an attempt to compare the Acharyas’s view of Asthi San-khya Shareera with the modern human anatomy.

scholarly journals Human Body in Traditional Views of Turkic and Mongolian Peoples: Blood and Circulatory System

2020 ◽  
Vol 34 ◽  
pp. 49-58
Author(s):  
M. M. Sodnompilova ◽  
◽  
B. Z. Nanzatov ◽  
Keyword(s):  
Significant Role ◽  
Human Body ◽  
Biological Fluid ◽  
Circulatory System ◽  
The Body ◽  
Human Anatomy ◽  
Hereditary Diseases ◽  
Inner Asia ◽  
The Social

The study of the human body in the system of traditional somatic ideas of the Turkic and Mongolian peoples of Inner Asia is urgent in the studies of humans as a social and biological beings. The problem of perception and comprehension of the composition of the main features constituting the human body, particularly such biological fluid as blood, is of particular interest in the study of mythological human anatomy. The interest in this element of the human body is due to the increased attention of the Turkic and Mongolian peoples to blood. The views on the nature of blood, the source of its formation, many prohibitions and signs associated with blood are known. Many concepts associated with human anatomy, including blood, formed the basis for the organization of the social structure of nomadic societies. Understanding the significant role of this biological fluid in the functioning of the body formed a certain system of ideas about the dependence of health, hereditary diseases and even a person's character on the appearance and volume of blood as the characteristics of this biological fluid available for visual perception. Blood unlike bone is mobile and changeable in the context of social interpretations. If the bone of the progenitor was not being changed passing to all his descendants, then the blood of representatives of the social community, who took women from different clans as wives, was mixed in marriage unions. The views of the Turkic and Mongolian peoples of Inner Asia on the composition of blood are characterized by uncertainty. The idea of a vital substance, a soul was widely developed in the worldview of the Turko-Mongols. Blood is one of the containers of the vital substance. A number of prohibitions and restrictions associated with blood allow us to talk about the significant role of the sun as a source of life, giving its vital energy to the blood. Obviously, evidence of this “relationship” is the color (red) and the warmth inherent to blood. However, ideas on the nature of blood formed in the traditional worldview of the Mongolian and Turkic peoples and recorded in the 18–19 centuries significantly differ from the early views of the ancestors of the nomads. Reconstruction of the Pra-Altai language made it possible to restore one of the key meanings of the term čiunu (blood) – “soul”, “wind”. We believe that early views on the nature of blood were greatly influenced by the phenomenon of respiration, which is characteristic of all beings.

scholarly journals Anatomia humana como ferramenta para promoção de educação em saúde na adolescência

2020 ◽  
Vol 11 (3) ◽  
pp. 331-338
Author(s):  
Magna Carolina Melo ◽  
Jaqueline Gabriele Silva ◽  
Caio Godinho Caldeira ◽  
Luísa Machado dos Santos Rocha ◽  
Brenda Oliveira ◽  
...  
Keyword(s):  
High School ◽  
Elementary School ◽  
Public Schools ◽  
Health Education ◽  
Private Schools ◽  
Human Body ◽  
Minas Gerais ◽  
The Body ◽  
Human Anatomy ◽  
School Students

A adolescência é um período de transição, marcado por transformações psicossociais, biológicas e comportamentais. Conhecer e compreender o corpo humano previne danos à saúde nessa fase. O projeto “Uma visita ao corpo humano”, desenvolvido na Universidade Federal de São João del- Rei, campus Centro-Oeste (UFSJ/CCO), baseou-se em visitas ao laboratório de Anatomia Humana, a fim de oferecer aos adolescentes do ensino médio e fundamental II das escolas públicas e privadas de Divinópolis, Minas Gerais, um esclarecimento acerca dos sistemas do corpo, enfatizando a saúde e o autocuidado. Foram selecionados 6 sistemas para as discussões, para as quais utilizaram-se peças sintéticas. Durante o ano de 2017, realizaram-se 18 visitas de 15 escolas diferentes. Foram atendidos 721 alunos. Desses, 350 (48,5%) frequentadores da rede pública, e 371 (51,5%) da particular. Do total, 458 foram alunos (63,5%) do ensino fundamental e 263 (36,5%) do ensino médio. Os resultados foram positivos, visto que os estudantes obtiveram mais acertos nas perguntas do teste, após as discussões. Além disso, observou-se superioridade do conhecimento prévio dos estudantes do ensino fundamental de escolas privadas. Palavras-chave: Adolescentes; Autocuidado; Corpo Humano; Extensão Universitária; Ensino Básico     Human anatomy as a tool to promote health education in adolescence   Abstract: Adolescence is a period of transition marked by psychosocial, biological, and behavioral changes. Knowing and understanding the human body prevents harm during this phase. The project “A visit to the human body” (“Uma visita ao corpo humano”) developed at the Federal University of São João del-Rei, campus Centro-Oeste (UFSJ / CCO), was based on visits to the human anatomy laboratory, in order to offer high school and elementary school adolescents from public and private schools in Divinópolis, Minas Gerais State, Brazil, an explanation about the systems of the body, emphasizing health and self-care. Six systems were selected for the discussions, in which synthetic parts were used. During 2017, 18 visits were made from 15 different schools, and 721 students were served. Of these, 350 (48.5%) attended public schools and 371 (51.5%), private ones. Of the total, 458 (63.5%) of elementary school and 263 (36.5%) of high school. The results were positive since the students scored better after the discussions. Moreover, higher knowledge was observed in primary school students from private schools. Keywords: Adolescents; Selfcare; Human Body; Health Education; University Extension; Elementary School

Sign in / Sign up

Export Citation Format

Share Document