Towards a new generation of virtual humans

Abdel‐Malek, Karim; Yang, Jingzhou; Marler, Timothy; Beck, Steven; Mathai, Anith; Zhou, Xianlian; Patrick, Amos; Arora, Jasbir S.

doi:10.1504/ijhfms.2006.011680

Cited by 76 publications

(7 citation statements)

References 39 publications

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“…Advances in digital human modeling have increased the need for mathematical representations of muscle strength about a joint, allowing for estimation of task requirements as a function of maximum capability. Digital human models also rely on accurate strength models when used to predict strategies of human movement [27, 30]. Several models of knee, elbow, shoulder and wrist strength are available [27–29, 31, 32], but we are aware of only two ankle strength models in the literature, one of which involved only dynamic strength assessments [13, 22].…”

Section: Introductionmentioning

confidence: 99%

3D strength surfaces for ankle plantar‐ and dorsi‐flexion in healthy adults: an isometric and isokinetic dynamometry study

Hussain

Law

2016

Journal of Foot and Ankle Research

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BackgroundThe ankle is an important component of the human kinetic chain, and deficits in ankle strength can negatively impact functional tasks such as balance and gait. While peak torque is influenced by joint angle and movement velocity, ankle strength is typically reported for a single angle or movement speed. To better identify deficits and track recovery of ankle strength after injury or surgical intervention, ankle strength across a range of movement velocities and joint angles in healthy adults is needed. Thus, the primary goals of this study were to generate a database of strength values and 3-dimensional strength surface models for plantarflexion (PF) and dorsiflexion (DF) ankle strength in healthy men and women. Secondary goals were to develop a means to estimate ankle strength percentiles as well as examine predictors of maximal ankle strength in healthy adults.MethodsUsing an isokinetic dynamometer, we tested PF and DF peak torques at five joint angles (−10° [DF], 0° [neutral], 10° [PF], 20° [PF] and 30° [PF]) and six velocities (0°/s, 30°/s, 60°/s, 90°/s, 120°/s and 180°/s) in 53 healthy adults. These data were used to generate 3D plots, or “strength surfaces”, for males and females for each direction; surfaces were fit using a logistic equation. We also tested predictors of ankle strength, including height, weight, sex, and self-reported physical activity levels.ResultsTorque-velocity and torque-angle relationships at the ankle interact, indicating that these relationships are interdependent and best modeled using 3D surfaces. Sex was the strongest predictor of ankle strength over height, weight, and self-reported physical activity levels. 79 to 97 % of the variance in mean peak torque was explained by joint angle and movement velocity using logistic equations, for men and women and PF and DF directions separately.ConclusionsThe 3D strength data and surface models provide a more comprehensive dataset of ankle strength in healthy adults than previously reported. These models may allow researchers and clinicians to quantify ankle strength deficits and track recovery in patient populations, using angle- and velocity-specific ankle strength values and/or strength percentiles from healthy adults.Electronic supplementary materialThe online version of this article (doi:10.1186/s13047-016-0174-1) contains supplementary material, which is available to authorized users.

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Section: Introductionmentioning

confidence: 99%

3D strength surfaces for ankle plantar‐ and dorsi‐flexion in healthy adults: an isometric and isokinetic dynamometry study

Hussain

Law

2016

Journal of Foot and Ankle Research

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“…There are many DHM software developed for various purposes and design needs as the 3DSSPP software for materials handling [18]. Moreover, SANTOS was developed serving different industries including aerospace, military, and medical ergonomics [21]. Another DHM software specialized for car crash simulations and safety MADYMO software [19].…”

Section: Introductionmentioning

confidence: 99%

Ergonomic analysis of a working posture in steel industry in Egypt using digital human modeling

et al. 2020

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This study presents solutions for improving a bending awkward posture in steel industry in Egypt using digital Human Modeling (DHM). The information is gathered by interviewing the workers, working postures are recorded via a video camera while the worker is performing his usual work. The postures are analyzed using DHM software. Porter comfort analysis and Rapid Upper Limb Assessment are applied for postures analysis. The analysis shows high levels of discomfort in neck, trunk, leg and forearm. These discomforts could cause permanent injuries over long periods. A modified design is proposed to reduce the fatigue caused by the original process. Furthermore, a comparison between the old and new design is performed. This study is important as workers comfort and productivity are increased when the work environment is ergonomically well-designed.

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“…In recent years, digital human modeling has been a fast growing area that bridges computer-aided engineering, design, human factors, applied ergonomics, and sports coaching and training and plays an important role in product design, prototyping, manufacturing, sports biomechanics, and many other areas [18,19,20]. A digital human model (DHM) is a digital representation of a human in three-dimensional (3D) space that can be moved and manipulated to simulate real and accurate movements of people.…”

Section: Introductionmentioning

confidence: 99%

“…A multilayer perceptron neural network was trained to generate the arm movements of a virtual mannequin based on the kinematic database of a participant [32]. Optimization approaches that minimize energy or muscular efforts have been developed to simulate upper body [33] and full-body motions [19,34]. Inverse kinematic methods from robotics have also been utilized to predict upper body reach motion [35,36].…”

Section: Introductionmentioning

confidence: 99%

A 3D Human-Machine Integrated Design and Analysis Framework for Squat Exercises with a Smith Machine

Lee

Jung

Lee

2017

Sensors

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Abstract:In this paper, we propose a three-dimensional design and evaluation framework and process based on a probabilistic-based motion synthesis algorithm and biomechanical analysis system for the design of the Smith machine and squat training programs. Moreover, we implemented a prototype system to validate the proposed framework. The framework consists of an integrated human-machine-environment model as well as a squat motion synthesis system and biomechanical analysis system. In the design and evaluation process, we created an integrated model in which interactions between a human body and machine or the ground are modeled as joints with constraints at contact points. Next, we generated Smith squat motion using the motion synthesis program based on a Gaussian process regression algorithm with a set of given values for independent variables. Then, using the biomechanical analysis system, we simulated joint moments and muscle activities from the input of the integrated model and squat motion. We validated the model and algorithm through physical experiments measuring the electromyography (EMG) signals, ground forces, and squat motions as well as through a biomechanical simulation of muscle forces. The proposed approach enables the incorporation of biomechanics in the design process and reduces the need for physical experiments and prototypes in the development of training programs and new Smith machines.

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Towards a new generation of virtual humans

Cited by 76 publications

References 39 publications

3D strength surfaces for ankle plantar‐ and dorsi‐flexion in healthy adults: an isometric and isokinetic dynamometry study

3D strength surfaces for ankle plantar‐ and dorsi‐flexion in healthy adults: an isometric and isokinetic dynamometry study

Ergonomic analysis of a working posture in steel industry in Egypt using digital human modeling

A 3D Human-Machine Integrated Design and Analysis Framework for Squat Exercises with a Smith Machine

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