This paper describes a human gait animation system with a precise neuromusculoskeletal model and evolutionary computation. The neuromusculoskeletal model incorporates 14 rigid bodies, 19 degrees of freedom, 60 muscular models, 16 pairs of the neural oscillators, and other neuronal systems. By changing the search parameters and the evaluative criteria of the evolutionary search process, we demonstrate various locomotive patterns, such as normal gait, pathological gait, running and ape‐like walking. The proposed simulation system takes not only kinematic data but also in vivo dynamic data such as energy consumption information into consideration, so that the resultant locomotion patterns are natural and valid from a biomechanical point of view. Hence the simulation system can also be used for finding a biologically appropriate physical model to realize a desired gait by simultaneously modifying the body dynamics parameters with the neuronal parameters. This capability creates a novel application of human gait simulation systems, such as rehabilitation tool design and consultation for physically handicapped people. Copyright © 2003 John Wiley & Sons, Ltd.

This paper reports on the development of a new lower limb prosthesis that can change its volume and hardness based on the users requirements. The size and viscosity of several Magneto-Rheological fluid filled bags, fixed on the inner side of the socket is changed, in order to vary the socket properties. TSB (total surface bearing) sockets have been most selling ones during these two decades. From the user's point of view, it is excellent in this type of sockets that the weight of user is supported with the entire socket surface. However, it is impossible to cope with the volume change of the user's stump. Experimental results show that the performance of the developed MR socket is better than the conventional TSB sockets because the MR socket is controllable in the size and viscosity.

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This paper proposes a method for enhancing the robustness of the central pattern generator (CPG)-based three-dimensional (3D) neuromusculoskeletal walking controller. The CPG has been successfully applied to walking controllers and controllers for walking robots. However, the robustness of walking motion with the CPG-based controller is not sufficient, especially when subjected to external forces or environmental variations. To achieve a realistic and stable walking motion of the controller, we propose the use of an attracting controller in parallel with the CPG-based controller. The robustness of the proposed controller is confirmed through simulation results.

The acquisition process of bipedal walking in humans was simulated using a neuro-musculo-skeletal model and genetic algorithms, based on the assumption that the shape of the body has been adapted for locomotion. The model was constructed as 10 two-dimensional rigid links with 26 muscles and 18 neural oscillators. Bipedal walking was generated as a mutual entrainment between neural oscillations and the pendulous movement of body dynamics. Evolutionary strategies incorporated, for example, as fitness in the genetic algorithms were assumed to decrease energy consumption, muscular fatigue, and load on the skeletal system. An initial population of 50 individuals was created, and an evolutionary simulation of 5000 steps was conducted. As a result, the shape of the body changed from that of a chimpanzee to that of a modern human, and the body size nearly reached the size of a modern human. These simulation results show that improving locomotive efficiency and reducing the load on the musculo-skeletal system are important factors affecting the evolution of the human body shape and bipedal walking, Such computer simulations help us to understand the process of evolution and adaptation for locomotion in humans.

Rowing ergometers can be found in most gyms and fitness centers, but many people who use them regularly have little or no instruction in rowing technique. It is not known whether nonrowers who regularly practice ergometer rowing are at risk of musculoskeletal problems. This study was done to quantify the differences in kinematics, kinetics, and musculoskeletal loading of competitive rowers and nonrowers during ergometer rowing. An experiment was performed to collect kinematic, external force, and EMG data during er-gometer rowing by 5 university-level competitive rowers and 5 nonrowers. Kinematic and external force data were input to a 3-D whole-body musculo-skeletal model which was used to calculate net joint forces and moments, muscle forces, and joint contact forces. The results showed that competitive rowers and nonrowers are capable of rowing an ergometer with generally similar patterns of kinematics and kinetics; however, there are some potentially important differences in how they use their legs and trunk. The competitive rowers generated higher model quadriceps (vastus) muscle forces and pushed harder against the foot cradle, extending their knees more and their trunks less than the nonrowers during the drive phase. They also had higher contact forces at the knee and higher peak lumbar and knee flexion moments. The ratio of average peak vastus force to average peak erector spinae force in the experienced rowers was 1.52, whereas it was only 1.18 in the nonexperienced rowers.

The work of fitting ceiling boards is one of the hardest in carpentry, as it requires large muscular power. Hence there is a need to develop assisting apparatus for such work. In order to use this apparatus anywhere a wearable robot is the most suitable. As the robot must be autonomous and lightweight, a design requiring low power is proposed. A semi-active control method has been developed using springs, which requires low energy but satisfies the requirements of compliance and assistive force. In this paper several aspects of design, control and experiments of the developed prototype is explained. The experimental results prove that the robot reduces the muscular fatigue of carpentry worker by providing suitable assistive force.

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