The objective of this study was to study the effect on the initiation of wheelchair propulsion from stationary sitting when pelvic posterior tilt was inhibited by a wheelchair cushion. [Subjects] The subjects were 18 hemiplegic patients who were capable of sitting in, and propelling a wheelchair. [Method] We used electromyography and a 3D motion analysis system to measure the posterior pelvic tilt angle, the muscle activity of the long head of the biceps femoris (BFLH), and the propulsion speed in the initiation of wheelchair propulsion from stationary sitting with three different types of cushion. [Results] The cushion which had the thigh pad removed on the propulsion side, having an anchor function, inhibited posterior pelvic tilt during initiation of propulsion from stationary sitting, BFLH activity was low, and fast propulsion was enabled. [Conclusion] The results suggest that inhibiting posterior pelvic tilt in stationary wheelchair sitting influences the propulsion initiation action.

[Purpose] The purpose of this study was to clarify postural control and muscle activity of the gluteus medius and musculus erector spinae in a single-leg stance before and after hip muscle abductor fatigue.[Subjects] Subjects were 22 healthy male adults (mean age; 21.4 yrs) with no significant medical history or current medical problems.[Methods] We examined postural control and muscle activity in a single-leg standing position before and after hip muscle abductor fatigue. A statistical analysis was performed using the paired t-test before and after muscle fatigue, and Pearson's rank correlation coefficient was obtained for muscle activity associated with postural control.[Results] The results indicate a significant increase in stability indices, a decrease in gluteus medius muscle activity, and an increase in right musculus erector spinae activity after fatigue. There was a positive correlation between the increase in right musculus erector spinae activity and increase in postural control. [Conclusion] We believe that postural control increased in the orientation related to the working of the muscles due to their fatigue, and that muscle activity increased to compensate.

[Purpose] This study sought to ascertain whether, in hemiplegic patients, the effect of a wheelchair cushion to suppress pelvic posterior tilt when initiating wheelchair propulsion would continue in subsequent propulsions. [Subjects] Eighteen hemiplegic patients who were able to propel a wheelchair in a seated position participated in this study. [Methods] An adjustable wheelchair was fitted with a cushion that had an anchoring function, and a thigh pad on the propulsion side was removed. Propulsion movements from the seated position without moving through three propulsion cycles were measured using a three-dimensional motion analysis system, and electromyography was used to determine the angle of pelvic posterior tilt, muscle activity of the biceps femoris long head, and propulsion speed. [Results] Pelvic posterior tilt could be suppressed through the three propulsion cycles, which served to increase propulsion speed. Muscle activity of the biceps femoris long head was highest when initiating propulsion and decreased thereafter. [Conclusion] The effect of the wheelchair cushion on suppressing pelvic posterior tilt continued through three propulsion cycles.

In this study, we investigated the relationship between balance and muscle power in postural control. [Subjests] Subjects were 21 healthy individuals. [Methods] First, static balance was assessed using a Romberg balance test (standing with eyes opened and eyes closed) combined with a GRAVICORDER ® (Anima, Japan). Then, we assessed active balance with the EQUITEST SYSTEM ® (NEUROCOM, Clackamas, USA). Subjects' muscle strength was determined by knee extensor strength and knee extensor time to peak torque using a Biodex ® (Biodex, USA), and by ankle plantar flexion and ankle dorsiflexion strength using a μ-Tas ® (MT-1; Anima, Japan). Statistical analyses were performed Pearson's product moment correlation coefficient. [Results] A significant relationship between muscle strength and active balance were observed. Individuals who have high muscle strength and short times to peak torque possess a high capacity of balance and of learning improved postural control. [Conclusion] Static balance may not be a predictor of falls due to low levels of body sway secondary to generally poor ROM seen in elderly individuals.

In this study, we used a monofilament algometer to make measurements and examined differences in plantar sensory threshold value between gender and four points on the sole of the foot. [Subjects] The subjects were 85 young persons (47 males and 38 females) without nerve or orthopedic disorders who provided their consent after receiving an explanation of the purpose of this study. [Method] One measurer measured the plantar pressure perception threshold value of each of the subjects. Gender and positional differences were examined using two-way analysis of variance with multiple comparison, Tukey's test, as a post hoc test. [Results] No gender differences between the four points on the sole of the foot were found. The perception threshold was greatest at the center of the heel, and declined in the order of the hallux, the head of the first metatarsal and the center of the medial longitudinal arch. [Conclusion] The results reveal that the parts of the foot which have the most mechanoreceptors have the lowest perception threshold values.