Many people get injured due to fall each year. Some individuals show a better performance in handling stability perturbations, which is related to the reaction pattern, and mainly to the physical capabilities, such as muscle strength, delay time, etc. Properties affecting the success of individuals' effort to regain their balance following a perturbation onset have been considered by the researchers. However, there is no solution so far that, for a given mechanical/control properties -as a representative model of an individual- determines this person is definitely robust regarding which domain of perturbations, and falls in case of others. Practical efforts should try to extend the domain of balanceable perturbations for an individual. Presently reported work addresses the question of from which initial states an individual can regain its balance. The state space may be divided into two regions, balanceable and unbalanceable, the boundary of which is in close relation with the individual's mechanical/control characteristics.

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Construction of driver's reach envelops including associated discomfort map is an important task for designing and assessing the operational range in a vehicle cockpit. The primary objective of this study was to build three dimensional reach envelops with associated discomfort map under simulated driving task condition. In addition, a statistical correlation and regression analyses were performed to indentify and quantify the effects of the geographical parameters of reach envelop on the discomfort rating. Using a digital human modeling scheme, reach motion was also reconstructed and further examined to figure out three dimensional joint angle change of body articulation which plays more important roles as biomechanical discomfort factors in reach motion.

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A numerical frontal impact sled model which consisted of driver side cockpit and elderly human body model was constructed for the optimal design of safety restraint system, i.e., air bag and seat belt. The objective function in this optimization process was to minimize the chest injury risk while keeping the other injury risks, i.e., HIC and femur load under the thresholds. There were three design variables for the restraint design, i.e., peak force of the shoulder belt load limiter, the firing time of pretensioner/airbag, and the vent hole size. It was confirmed that a lower restraining force and hence the earlier airbag/pretensioner firing time to capture more excursive upper body compared to the younger driver were needed to mitigate the chest injury risk of the elderly driver.

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An active joint motion of human body is normally produced by non-isometric skeletal muscle contractions through the motor control. These non-isometric skeletal muscle contractions induce substantial shape change of the muscle segment, e.g., bulged belly of concentrically contracting muscles and consequently the interaction with the tight clothing or footwear becomes an important design issue. In order to simulate both contractile muscular forces and associated volumetric changes using digital human body models, the FE based hybrid muscle modeling approach in which three-dimension solid elements are reinforced with one-dimensional Hill type bar elements respectively representing muscle substrates and fibers is introduced. The lower leg muscles and their actions on ankle joint motions (dorsi/plantar-flexions) are accordingly modeled, simulated and quantitatively validated against a live subject experiment.

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The static and dynamic strain of the breast mass of four participants were measured while standing and running using a five-camera passive marker system running at 200 Hz. When stationary, the static downward strain of the breast increased with breast size and decreased with use of an everyday bra, and further with a sports bra. Plots of force-strain on the breast mass during motion showed clear non-linearities above 40% strain in agreement with previous studies on skin and tissue. The peak forces during motion increased with breast mass and were reduced by the wearing of a bra, and in particular a sports bra. The relationship between bra condition and peak strain during motion was less clear.

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Three-dimensional photogrammetric deformation and strain mapping systems are becoming of interest to the athletic footwear industry for use in empirically-driven, targeted design of footwear. In this study we have developed a novel application of the GOM ARAMIS digital image correlation strain mapping system for measuring the surface strain experienced by a snowboard boot under conditions of dynamic loading. The methodology attempts to recreate externally valid rates and ranges of movement using an industrial robot and notionally biofidelic prosthetic limb. The methodology is applicable to other types of athletic footwear and soft sporting goods.

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Analysis of over 120 years of elite sporting performances showed that the mean performance data for each year is needed to allow the effect of interventions such as rule changes and the introduction of new technologies to be assessed. Performance data such as times and distances were converted to a performance improvement index to enable comparisons between sports. Fitting of mathematical models to the data showed that the limit of the mean performance in the 100 m sprint limit is 15% higher than that in 1948. The introduction of fully automated timing in 1975 produced an apparent reduction in performance of 3.6% while the Olympics produces a small oscillation in performance of 0.3%. The 1986 rule change in the javelin reduced performances by 13% while the introduction of new materials in the pole-vault was estimated to have improved performances in the 1960s by around 15%.

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