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Bra design experiences a long process of development including some key aspects like material selection, pattern making and grading. The design and development processes are highly complex, which consist of many pattern engineering stages, specialized technologies and multiple trial-and-errors. It is anticipated that a 3D bra design that incorporates information on the interaction between bra and breast can effectively improve the design process for optimal fit and comfort. In this paper, a novel personalized modeling system based on finite element (FE) contact model is first presented to simulate the breast-shaping effect and the pressure distribution of the skin exerted by a bra. The new knowledge can provide a basis for the computer-aided-design of well-fitting bras for the target customers. The FE body sub-models include a rigid torso and two soft breasts wearing a bra with or without an underwire. The geometry of the body was based on the 3D-scan data and the property of the breasts was considered a hyper-elastic Mooney–Rivlin model for simulating the deformation of the breasts. The simulation of bra wearing was performed by an FE contact model in a user-defined coordinate system. There were two main steps: (1) closing the shoulder straps and bra underband at the center back of the body, and (2) adjusting bra position using “virtual hands”. The simulation results showed that although the wireless bra exerted less pressure on the breast, the shaping effects in terms of lifting, gathering and protruding were more obvious in the underwired bra. This result is consistent with the actual bra-wearing. The effect of wireless bra on the breast deformation was three fifths of the effect of underwired bra and this relationship could be used to predict the deformation of breasts with different materials of underwire at the early stage of bra design. The relative errors between simulated results in terms of the breast deformation and pressure distribution with a fitting experiment on an underwire bra were less than 10%. The FE model developed in this study, therefore, can be used as fundamentals for various sensitivity analyses about different bra design features for predicting the deformation of the breast shapes and comfort pressure with reasonable accuracy.

It has been a long-standing problem in the engineering design of bra for optimal support and shaping due to the difficulty of quantifying the hyper-elastic properties of human breasts. The objective of this study is to determine an optimal approach to obtain the non-linear properties of breast soft tissues and the corresponding deformations during motions. The Mooney-Rivlin material parameters of the breasts in-vivo were verified through an optimization process that involved iteratively changing the material coefficients with the integration of static and dynamic finite element models. Theoretical equations of a rigid-flexible coupled system during the motion of forward-leaning were established with gravitational, centrifugal and Coriolis forces to simulate the dynamic deformation of the flexible breasts. The resultant, optimally generated, coefficients of the Mooney-Rivlin hyperelastic material type for the breast were found. This new set of breast material coefficients was verified by finite element analysis of the breast deformation during forward-leaning and running movement. The method proposed in this study provides an effective way to determine the breast properties for predicting breast deformation and analysis of the bra-breast contact mechanism and thus, improving the design of bras.

Indoor slippers with a strap across the dorsal forefoot are popular with older women. However, their influence on the foot motion has not been reported. This study evaluated the range of movement in the knee and ankle joints during walking and changes in trunk displacement during sit-to-stand when ten healthy older women worn two types of slippers and in their barefeet. Comparing to barefeet, walking in slippers results in significantly increases in the knee flexion angle in the swing phase. However, there is nonsignificant difference in the ankle angle in any phase across all conditions. During the sit-stand transition when slippers are worn, there is a significantly reduction in the peak trunk tilt angle and range, as well as the duration of the weight shift when motion is initiated. The findings therefore provide a better understanding of slipper features and designs associated with changes in foot kinematics in older women.

Spinal motor control can provide substantial insight for the causes of spinal musculoskeletal disorders. Its dynamic characteristics however, have not been fully investigated. The objective of this study is to explore the dynamic characteristics of spinal motor control via the fractional Brownian motion mathematical technique. Spinal curvatures and repositioning errors of different spinal regions in 64 children of age either 11 or 15 year-old during upright stance were measured and compared for the effects of age and gender. With the application of the fractional Brownian motion analytical technique to the changes of spinal curvatures, distinct persistent movement behaviors could be determined, which could be interpreted physiologically as open-loop behaviors. Moreover, it was found that the spinal motor control of 15 year-old children was better than that of 11 year-old children with smaller repositioning error and less curvature variability as well as shorter response time and smaller curvature deformation.

This research aimed at investigating the method of using kinetic typography and interactive approach to conduct a design experiment for children to learn vocabularies. Typography is the unique art and technique of arranging type in order to make language visible. By adding animated movement to characters, kinetic typography expresses language meanings in a better and dynamic way. Kinetic typography may also help children to clearly grasp the relationship of difficult words by means of expressing, understanding and experiencing the cognition process. When children interact through the dictionary with animated typeface and movement, it brings on a more functional and profound impression on them for gaining knowledge. The present study takes children’s development and learning theories into consideration by analyzing how they acquire information through interactive process to enhance their involvements. This study shows through the implementation of motion graphics, kinetic typography and information design, that a more diversified learning experience can stimulate and strengthen the sensitivity of children in their perception and learnability. It can also enhance children’s understanding on the meaning of vocabularies, through kinetic expressions.

From previous biomechanical researches, postural sway has been generally evaluated by descriptive statistics for the purpose of scientic and clinical purposes in analysing the variety of external perturbations and the corresponding responses by the human body. Although these approaches on analysing the responses enable the examinations on the characteristics and relationships between the input and output of different feedback systems, the stabilizing mechanism or the steady-state behaviour from the possible control schemes of the human body is not explicitly considered. In this research study, the multifractality structure on postural sway is identied by the numerical method on multifractal detrended uctuation analysis. An experimental set of 11 healthy subjects were investigated by optical motion capture system from the retroreective optical marker data attached on skin surface along the spinal curvature. It is observed that random walk characteristics, hence, correlations between present and history of data, are present in the time series. Multifractal detrended uctuation analysis is further applied to get into the details about the correlation of data along the time series. The study reveals the degree of multifractality extracted from the data, and compares to shufed data to ascertain the multifractality in spinal curvature movement is predominantly due to long-range correlations instead of probability distributions. The application of this computational technique attempts to describe the multiple strategies utilized by the motor control in response to static, yet swaying, human body posture.

Effective training to improve serve speed is important for competitive tennis players. The purposes of this study were to investigate the effects of anthropometric factors and whole body kinematics of elite players on ball speed and to propose possible training strategies for improving the quality of tennis serves. Body and racket kinematics of tennis serves of 12 male elite Hong Kong players were investigated. The tennis serve was divided into four phases: I) Back-Swing Phase, II) Lead-Leg-Drive Phase, III) Forward-Swing Phase, and IV) Follow-Through Phase. It was shown that racket-side knee range of motion during phases II and III (r=0.705; p<=0.05), racket-side knee peak extension velocity during phase II (r=0.751; p<=0.01), racket-side hip peak extension velocity during phase II (r=0.657; p<=0.05), racket-side shoulder range of motion in the coronal plane during phase III (r=0.616; p<=0.05), racket-side elbow peak extension velocity during phase III (r=0.708; p<=0.01) and body mass index (r=0.577; p<=0.05) were significantly correlated with ball speed. Body mass index and the identified kinematic parameters that were significantly correlated with ball speed could be used as training guidelines for coaches and players to improve serve speed. Players should pay particular attention in training to increasing the extension velocity and range of motion of the identified joints.

Literature reflects that there is considerable amount of research has been conducted concerning motor control and postural control of human body. Research findings also reveal the importance of stability and variability of movement in relation to spine, in particular. However, the evaluation method on stability and variability of spinal movement is limited on the linear methods in revealing the significance of movement. The knowledge on the nonlinearity and the dynamic features of spinal movement is still inadequate in describing the motor control and musculoskeletal characteristics. The aim of this chapter is to explore into area of understanding how human body maintain posture in a dynamic manner under the context of non‐analytical method of spinal motor control and the kinematic resultant of musculoskeletal system. Based on the research outcomes, contribution can also be made into the application domain of evaluating motor control characteristics as reflected from different subject profiles.

Effective training for improving serve velocity is important for elite tennis players. The objective of this study is to investigate the relationship between whole body kinematics and ball velocity of tennis serve of Hong Kong Elite Tennis players. Twelve Hong Kong Tennis Team male players were recruited. Body kinematics of the players during tennis serves were monitored by a motion analysis system (Vicon MX, Oxford Metric, Oxford, UK) and correlated with the ball velocity. Compared to the Olympic 2000 tennis players, the front knee peak extension velocity, pelvic peak axial rotation velocity, trunk peak right rotation velocity, shoulder peak internal rotation velocity, elbow peak extension velocity and wrist peak flexion velocity of the Olympic players were 5, 2.1, 4.1, 2.9, 2.8 and 2.9 times, respectively, faster than those of the Hong Kong Elite Players. The mean serve velocity of Olympic players (182.9+/-14.0 km/h) was significantly faster than that of the Hong Kong Elite players (145.4+/-19.9 km/h; range: 119-180). The velocity of tennis serve of Hong Kong Elite players was within the range of the lower-level tournament western play-ers. The slower ball velocity of Hong Kong Elite players might be due to the differences in kinematic profile during serve. It was also found that the right shoulder peak internal rotation velocity, right rear knee range of motion, right rear hip peak extension velocity, right shoulder rotation range of motion and body weight were significantly correlated with the ball veloc-ity. Stepwise linear regression analysis showed that the right shoulder peak internal rotation velocity and body weight were significant predictors for ball velocity which contributed 3.8%, 85% respectively to the total variability (r2 = 0.878, p<=0.05). The body kinematics and body weight were shown to have significant effects on ball velocity of tennis serve. Kinematic Study of Serve Velocity of Hong Kong Elite Tennis Players.

Motion segmentation and analysis are used to improve the process of classification of motion and information gathered on repetitive or periodic characteristic. The classification result is useful for ergonomic and postural safety analysis, since repetitive motion is known to be related to certain musculoskeletal disorders. Past studies mainly focused on motion segmentation on particular motion characteristic with certain prior knowledge on static or periodic property of motion, which narrowed method's applicability. This paper attempts to introduce a method to tackle human joint motion without having prior knowledge. The motion is segmented by a two-pass algorithm. Recursive least square (RLS) is firstly used to estimate possible segments on the input human-motion set. Further, period identification and extra segmentation process are applied to produce meaningful segments. Each of the result segments is modeled by a damped harmonic model, with frequency, amplitude and duration produced as parameters for ergonomic evaluation and other human factor studies such as task safety evaluation and sport analysis. Experiments show that the method can handle periodic, random and mixed characteristics on human motion, which can also be extended to the usage in repetitive motion in workflow and irregular periodic motion like sport movement.

This paper presents an efficient method to generate a large amount of continuous motion data from motion captured data. Given user defined way point lists for each agent, the algorithm can automatically generate collision free walking paths for them. The walking path data is then analyzed and transformed into a sequence of agent states such as walking or standing state. Based on the randomized depth first algorithm, the agent states are matched with a sequence of corresponding motion clips. The final motion is obtained by blending the motion clips to fit with the speed of the agents' walking paths. From our experiments, our algorithm generates natural looking motions.

Occupational health get more concern in recent years, turning the ergonomic and human factor issues an essential consideration in product design process. In a survey presented in [4], over 90% of designers and engineers recognized that they needed to consider ergonomics earlier in the development processes. However, most of the assessment is done by engineers since designers always encountered technical difficulties to run such assessment. In this paper, we present a method for designers to adopt the engineering assessment for biomechanics and ergonomics on human posture at early product design phase. The aim is to allow designers to easily perform the design evaluation with minimal intensive technical training. The proposed method is implemented in the experiments to evaluate a sample workplace design for desktop work. Human motion data is captured and then applied to a digital human model and passed to assessment software to realize the human posture and evaluated based on existing ergonomic assessment scheme Rapid Upper Limb Assessment

In this paper, we present an algorithm for motion synthesis. This algorithm is developed as a part of a large crowd simulation project which simulates the motion of the people by using a large database of motion captured data. Most of the crowd simulations divide the simulation process into two phases, the first phase is path generation, and the second phase is matching the motion clip to the generated path. The second phase is the goal of this paper. There are two problems we need to solve for the second phase. The first problem is that the generated motion should be attached to the path, and the speed of the generated motion must be matched with the path. The second problem is that the crowd simulation simulates different size of people, that is, the skeleton is scaled.

In a survey presented by Broberg (1997), over 90% of designers and engineers recognized that they needed to consider ergonomics earlier in the development processes. Human-centered design including usability and ergonomics assessments is necessary. Direct involvement of users in testing is becoming of great importance. Existing computer-aided design (CAD) systems and digital human modeling (DHM) software appears to be the simulation tools providing necessary conditions for ergonomics analysis together with associated graphics to allow both product and process designers to better understand the potential problems when operating or servicing a proposed design. One major limitation is that designer need to spend a great deal of time building and rendering the digital space with enough details, describing the task inputs, and specifying both physically constrained and unconstrained conditions necessary to perform the simulation and analysis. Unfortunately, designers usually have little time and technical training in ergonomics in order to accomplish this objective. Moreover, posture and motions of people are not well modeled and predicted in existing DHMs using IK and other related robotics method especially in validating complex dynamic task simulations. In this paper, we present a process that can be adopted by designer to have preliminary ergonomic assessment on their concept design at early development phase. The aim is to allow designers to easily adopt the process with minimal intensive technical training. It can also reduce the number of iterations on process development between designer and engineer, that usually takes months and costly to build physical mock-ups or prototypes in order to allow evaluation and assessment.

While many previous works to generate human motion has been proposed, these techniques are offline, memory inefficient and may require past and future time frames during the synthesis process. The objective of this paper is to propose an algorithm for human motion synthesis which targets for real-time applications. This algorithm was originally developed under a crowd simulation project which simulates the motion of the people by using a motion captured data library. Four main features of this synthesis algorithm include generating motion along a given path with the speed matched, adapting the motion to the scaled skeleton, running with an interactive speed and small memory footprint

In a survey presented by Broberg (1997), over 90% of designers and engineers recognised that they needed to consider ergonomics earlier in the development processes. Human-centred design including usability and ergonomics assessments is necessary. Direct involvement of users in testing is becoming of great importance. Existing computer-aided design (CAD) systems and digital human modelling (DHM) software appear to be the simulation tools that provide the necessary conditions for ergonomics analysis, together with associated graphics, that allow product and process designers to better understand the potential problems when operating or servicing a proposed design. One major limitation is that designers need to spend a great deal of time building and rendering the digital space with enough detail, describing the task inputs, and specifying both the physically constrained and unconstrained conditions necessary to perform the simulation and analysis. Unfortunately, designers usually have little time and technical training in ergonomics in order to accomplish this objective. Moreover, posture and motion of people are not well modelled and predicted in existing DHMs using IK and other related robotics methods, especially in validating complex dynamic task simulations. In this paper, we present a process that can be adopted by designers to have preliminary ergonomic assessment on their concept design at the early development phase. The aim is to allow designers to easily adopt the process with minimal intensive technical training. It can also reduce the number of iterations on process development between designer and engineer that usually takes months, and reduce the need to build expensive physical mock-ups or prototypes in order to allow evaluation and assessment.

Biomechanical study of posture is one of the most referenced aspects for ergonomic evaluation processes in workplace design. The aim of this paper is to present approaches for analysis of task performance and to illustrate ergonomic interpretation of the results. The proposed method, based on the optical system for motion capture, has allowed the measurement of a large set of subject postures and parameters in a continuous time basis and convenient manner. Statistical analysis can be done on the captured data to identify specific body part characteristics for posture and ergonomic analysis. Based on the results, a mock-up design can be evaluated against human factors in early design phases.

Sketch-drawings is an intuitive and comprehensive means of conveying movement ideas in character animation. We proposed a novel sketch-based approach to assisting the authoring and choreographing of Kungfu motions at the early stage of animation creation. Given two human figure sketches corresponding to the initial and closing posture of a Kungfu form, and the trajectory drawings on specific moving joints, MotionMaster can directly rapid-prototype the realistic 3D motion sequence by sketch-based motion retrieval and refinement based on a motion database. The animators can then preview and evaluate the recovered motion sequence from any viewing angles. After the 3D motion sequence has been associated with the 2D sketch drawing, the animator can also interactively and iteratively make changes on the 2D sketch drawing, and the system will automatically transfer the 2D changes to the 3D motion data of current interests. It greatly helps the animator focus on the movement idea development during the evolutionary process of building motion data for articulated characters.

In most motion editing approaches, the users often make changes on mocap data by specifying numerical parameters. However, it is not intuitive for a novice to edit motion sequences in motion planning tasks. In this paper, we present a method of notation-based motion editing, in which Labanotation, a well-developed notation language for human movements, is employed as the editing interface. It allows the user to specify the editing requirements via notation score, and the system will semi-automatically generate the desired motion data. The algorithmic steps of its pipeline and the core issues of converting Labanotation into motion sequences are discussed in detail. We show the results of our systems using martial arts motion as its testing data.