Changing of standing position and visual blocking methods have been used as a convenient evaluation of standing balance by physical therapists. The purpose of this study was to investigate the effects of changes of foot positions on Romberg's quotient of postural sway and the tibialis anterior and gastrocnemius muscles activities in standing for normal men. Subjects were 45 college students. For the measurement of muscles activities, 15 subjects were selected at random from among the 45 students. The standing positions were standing with legs 10 cm apart, standing with legs together, tandem standing, standing on tiptoes, and standing on one leg with the eyes open and closed. Measurements were made using a center of foot pressure recorder and surface electromyography for 30 seconds. Romberg's quotient and the relative muscle activities of the leg were both found to be in the order standing with legs apart, standing with legs together, tandem standing, standing on tiptoes, standing on one leg. It has conventionally been considered that the instability of postural sway is increased when vision is blocked. The present results suggested that postural regulation by the physiological subsystem is indirectly affected by vision and somatosensory input.

Until now, numerous studies on the effects of electrical stimulation on nerve cell activation in a cell culture have been conducted. However, there are very few studies that have used the three-dimensional (3D) culture system to investigate nerve cell axonal extension. In this study, we developed a novel 3D direct current electric field (DCEF) stimulation bioreactor, which can uniformly stimulate cultured nerve cells for a long period. We observed the morphogenesis of PC12 cells using a multi photon excitation fluorescence microscope (MPM) and evaluated DCEF stimulation effects on PC12 cells axonal outgrowth. First, a DCEF stimulation bioreactor was designed using finite element analysis for uniform electric field. We, then, validated the uniform stimulation of PC12 cells using this bioreactor for 24 h. Second, we determined the optimal stimulation condition using the response surface method and adopting objective functions, such as axonal length, the ratio of axonal orientation towards the anode, and design parameters, such as the electric field strength and the duration of the stimulation. We found the optimal condition to be 43 mV/mm and 6.2 h/day for axonal length enhancement. An increase of 20.1% against the condition for the control group (Mann-Whitney's U test, p<0.05) was obtained. In addition, the 92 % of PC12 cells were oriented toward the anode with 90 mV/mm, 24 h/day condition. However, the axonal formation was suppressed depending on the stimulation duration. Finally, we found the optimal conditions of 70 mV/mm and 7.9 h/day for achieving the enhancement of axonal extension and orientation, simultaneously.

No abstract

No abstract

ABSTRACT:The effects of a cognitive motor task of the foot sole upon standing posture balance stability were examined in a glioblastoma case with impairment of standing posture balance. In the foot sole discrimination task, the patient, in a sitting position, was required to put his foot on a board that was unstable in the abscissa or ordinate axes and to maintain the board horizontally, and moreover to judge the location of a weight that was loaded on either side of the board. This cognitive motor task was performed 10 times for each foot and the number of correct judgments was recorded. Also, sway of the center of gravity in a standing position with eyes open or closed was measured every 3 or 4 days. The standing postural sway decreased with cognitive motor learning, suggesting that control of standing posture balance can be established effectively through cognition of the shift in the center of gravity using internal somatosensory information, and also that this type of cognitive motor task is useful as a training strategy for standing posture balance impairment.