The purpose of this study was to compare ankle joint loads (Linear and Angular Impulses) while descending the stairs and ramp. Ten young male subjects participated in this study. Stairs and ramp of identical slope (30 degrees) were custom-made to include force plates in the middle of pathways. Subjects descended the stairs and ramp at a comfortable speed and posture. The stance period was divided into three phases, weight acceptance (WA), single limb stance, and pre-swing. Three-directional impulses and their sum were derived from the reaction forces and moments at the ankle joint. Differences in impulse sums (Both Linear and Angular) between stairs and ramp were significant only in the early (WA) phase, whereas those of stairs were greater than the ramp. All subjects adopted forefoot strike strategy for the stairs and 80% of the subjects adopted rearfoot strike strategy for the ramp. An increase in the GRF and moment arm of the GRF at the ankle joint in case of forefoot strike may have contributed to the increase in the linear and angular impulse in the early phase of stair descent compared to ramp descent. The results are in agreement with the preference of ramp in the elderly.

Maintaining balance is a factor critical and integral to our effective physical function as it relates to the normal activities of daily living. Of the “hip strategy”, “stepping strategy” and “ankle strategy”, it is known and accepted that the “ankle strategy” is the first activated parameter to assist in the maintenance of balance in motor output. However, few studies actually evaluated or assessed the precise attributes of “ankle strategy” in relation to any therapeutic effort tocorrect and/or rehabilitate from physical imbalance caused by dynamic tilting perturbation. The aim of the study was to identify precise characteristics of the “ankle strategy” as they respond to dynamic tilting perturbations. Seven healthy male (aged 25.5 ± 1.7 years, average height of 173.9 ± 6.4 cm, average body mass of 71.3 ± 6.5 kg) were recruited to participate. The ankle joint motions were subjected to eight dynamic tilting perturbations generated by the customized tilting perturbation simulator, and the responses were measured by 3D motion capture system. Concurrently, foot pressure distribution and the corresponding centers of pressure (COP) trajectory were measured by a pressure measuring system, and the four main muscles’ activations related to the ankle joint motions were measured by wireless electromyogram system.

Recently, a Total Ankle Arthroplasty (TAA) has been commonly used when no other options are available for patients with severe arthritis at the ankle joint. But bone resorption, aseptic loosening, instability, malalignment and fractures are generally known as the main reasons of TAA failures. Those TAA which have been designed up until now are generally based on the morphological and kinesiological characteristics of the ankle joint. They are adjusted by the ankle joint size of Westerners, although both the morphological and mechanical (strength) characteristics of the ankle joints of Asian are important in the development of a TAA suitable to Asians. Little information about the morphological and mechanical characteristics of the ankle joint of Asians is available for the development of a TAA suitable to Asians. The purpose of this study was, therefore, to analyze the morphological and mechanical characteristics of the ankle joints of Asians. Computed tomography data obtained from 50 patients (mean age: 64.14 ± 9.34 years) were analyzed.