The tibio-femoral contact area in five current popular total knee joint replacements has been measured using pressure-sensitive film under a normal load of 2.5 kN and at several angles of flexion. The corresponding maximum contact pressure has been estimated from the measured contact areas and found to exceed the point at which plastic deformation is expected in the ultra-high molecular weight ...

This paper investigated the factors that influence Hecht vault performance and assessed the level of model complexity required to give an adequate representation of vaulting. A five-segment planar simulation model with a visco-elastic shoulder joint and a torque generator at the shoulder joint was used to simulate the contact phase in vaulting. The model was customised to an elite gymnast by de...

A technique of idealising frame models using substructures is outlined. All joints are modelled in 3D but, using substructures, each 3D joint is converted to an equivalent stiffness element. The slender regions between the joints are modelled using beam elements. Coupling between the substructures and beam elements is carried out in a manner that conforms with the theory of elasticity. Post-ela...

In this paper we investigate how spring-like leg behavior in human running is represented at joint level. We assume linear torsion springs in the joints and between the knee and the ankle joint. Using experimental data of the leg dynamics we compute how the spring parameters (stiffness and rest angles) change during gait cycle. We found that during contact the joints reveal elasticity with stro...

This paper presents a mechanical system with a similar configuration to a human musculo-skeletal system for use in anthropomorphic robots or as artificial limbs for disabled persons. First, a mechanical module called ANLES (Actuator with Non-Linear Elasticity System) is introduced. There are two types of ANLES: the linear-type ANLES and rotary-type ANLES. They can be used as a voluntary muscle ...

Establishing cultures of human embryonic (ES) and induced pluripotent (iPS) stem cells in xeno-free conditions is essential for producing clinical-grade cells. Development of cell culture biomaterials for human ES and iPS cells is critical for this purpose. We designed several structures of oligopeptide-grafted poly (vinyl alcohol-co-itaconic acid) hydrogels with optimal elasticity, and prepare...

This paper studies the lap shear, in which both adhesive and adherends are elastic, but is much softer than adherends. The shear lag model identifies a length, called length Ls. energy release rate of debond crack affected by elasticity Their relative importance characterized ratio remaining joint, L, to In short-joint limit, L/Ls→0, do not deform, gives rate. long-joint L/Ls→∞, interior does a...

The means whereby animals adapt their locomotor behavior to variation in environmental conditions is an important and neglected problem in the area of motor control. To investigate this problem, young (3-month-old) pigtailed macaques (Macaca nemestrina) were filmed leaping a fixed distance from both rigid and elastic take-off supports. Sixteen of 17 subjects exhibited substantial invariance in ...