Non-rigid movement of the soft tissue interface between skin-mounted markers and the underlying bones, also known as soft tissue artifact (STA), poses a major limitation to the non-invasive estimation of joint kinematics using three-dimensional (3D) motion analysis systems. Thorough knowledge of the nature of this non-rigid behavior is essential for development of compensation algorithms to enhance the accuracy of these systems. The studies in the literature aimed at quantifying STA have implemented invasive measurement methods such as bone pins [1] and external fixator devices [2], or have used subjects with pathological conditions [3]. In the present study, we integrated Magnetic Resonance (MR) and X-ray imaging techniques to evaluate the non-rigid behavior of the lower-limb soft tissue of healthy adults for a number of different functional tasks.

Falls are a significant health concern among older adults. The rate of falls increases with age [1], and often leads to fall-related injuries such as fractures and head injuries. These lead to loss of independence, morbidity and fear of falling [2]. There are many strategies used to prevent falls, including those used to regain balance following a slip or trip. One such balance recovery maneuver is the step response, which involves respositioning the body’s base of support to recapture its moving center of mass [3]. Age-related performance declines in the step response may contribute to fall risk, especially during the step response landing phase where biomechanical strength requirements are largest [4]. Such age-related declines likely manifest themselves as alterations in lower extremity joint dynamics. While these effects are likely present in all lower extremity joints (hips, knees, and ankles), the purpose of this preliminary study was to investigate age effects in stepping leg ankle dynamics during a balance-restoring step response.

Work-related falls are still a major cause of injuries and fatalities, even after continuous efforts towards improving worker safety. Falls accounted for more than 20% of nonfatal occupational injuries and were the second leading cause of occupational fatalities in the United States [1,2]. Given projections showing an increasing number of workers over the age of 55 [3], the older population must be considered in assessing the risks and prevention of work-related falls.

Foot morphology and gait patterns of children have been explored in order to understand the developmental stages [1–3]. However, these studies have mostly focused on static and walking conditions. The purpose of this study was to investigate the development of running in children between the ages of 3 and 11 years and to investigate gender differences. This was done as a multi-lab, multi-country study; but the foot pressure results from the Japanese children are presented here.

Walking programs provide an attractive intervention to address the preservation of bone mass in the aging population. Research suggests one in three women and one in five men over 50 will experience fractures due to osteoporosis [1,2]. Bone is a mechanically modulated tissue and thus, training programs that prescribe physical activities that dynamically load the skeleton through either muscle contractions (strength training) or locomotion (walking/running) would be expected to have a positive influence on bone mineral density (BMD) preservation. However, attempts to implement activity programs in populations at risk for developing osteoporosis to accrue or simply preserve bone mass have had limited success [3] due to a variable response between subjects. It has been suggested that the failure of these programs to significantly influence bone mass or density may be due to individual differences in the loads generated by the prescribed exercise regimes and/or the knowledge of specific types, intensities and volumes needed for effective osteogenic exercise. Walking, a simple, common activity, presents an interesting opportunity to examine the potential for individual differences in the style of walking to explain the variability in individual results to training programs designed to preserve bone density.