Previous studies have reported kinematic coupling between shank and foot segment. However, it remains unclear whether as to kinematic coupling among foot segments. The purpose of this study was to investigate the effects of kinematic coupling between hindfoot and midfoot segments at different modes of run and normal gait. Six healthy young men participated in this study. Subjects were instructed to run (at 2. 5 m/ s) or gait (at 1. 3 m/ s) on the treadmill at speeds set by the examiner. The changes in angles of foot segments during stance phase were calculated based on 3D Foot model. The degree of kinematic coupling between hindfoot and midfoot segments was evaluated by Pearson’s correlation coefficient. Positive correlation indicated the occurrence of the kinematic coupling of pronation of the hindfoot with plantar flexion, pronation and abduction of the midfoot. Similarly, kinematic coupling of supination of the hindfoot with dorsi flexion, supination and adduction of the midfoot were expressed by positive correlation. In running, strong correlations were observed between pronation/supination of hindfoot and three movements of midfoot; 1) plantar/dorsi flexion (r = - 0. 79), 2) pronation/supination (r = 0. 99) and 3) abduction/adduction (r = 0. 85). In gait, the correlation between pronation/supination of hindfoot and plantar/dorsi flexion of midfoot became weak (r = 0. 24). Abnormal responses of the kinematic coupling between the foot segments to changes in modes would be an indicator of dysfunction of the foot segment.

The purpose of this study was to clarify the effects of the kinesthetic illusion produced by visual stimulus on production of voluntary movement. Nine healthy male subjects participated in this study. To produce the kinesthetic illusion, we used video footage consisted of own wrist joint movement of palmar flexion and dorsal flexion. The subjects completed the three experimental conditions: illusion condition, observation condition and rest condition. In the illusion condition, the kinesthetic illusion was produced during watching the movie, which was projected on a display that was set over right forearm. In the observation condition, the subjects observed the computer display, which was set at away from their own hand. As eff ects of kinesthetic illusion on a production of voluntary movement, reaction time in response to Go/No go task was measured employing calculated EMG onset in the right FCR muscle. The result of the present study showed that reaction time was significantly delayed only in the illusion condition. Although there was no evidence that indicates physiological mechanism of involvement of voluntary movement in the present study, the effect of the kinesthetic illusion induced by visual stimulus on production of voluntary movement was clearly indicated.

Many previous studies have been devoted to research intrinsic and extrinsic factors leading to falls. Recently, errors in the initial weight transfer of the postural responses prior to a step (anticipatory postural adjustment errors: APA errors), an indicative of motor program errors, and their possible relations to inhibitory control are reported. The purposes of the present study were to quantify the underlying mechanisms of APA errors and to investigate whether the APA error evaluation can potentially detect fall risks. 11 healthy young adults performed visually-cued step initiation tasks. We applied simple and choice reaction time tasks and the Simon task which consisted of congruent and incongruent conditions. Evidence of postural adjustment errors and stepping parameters were confi rmed with center of pressure obtained from a force plate. Results show that APA error rates were higher in the incongruent condition of the Simon task than the other tasks. The further analysis after dividing the trials according to whether APA error occurred revealed that the reaction time of APA error trials was shorter than non-APA error trials in both congruent and incongruent conditions. In addition, the foot-lift time of APA error trials was longer than non-APA errors trials. These results suggest that visual interference by the Simon task impaired judgment processes during stepping, leading to an increase in initial motor program errors, speeded reaction time and prolonged foot-lift time.

Reloading is one of the effective interventions for recovery after muscle atrophy. Nutritional strategies also promote this effect. Muscle recovery from atrophy is related to increase the muscular protein synthesis and the number of myonuclei. In addition, the muscle protein synthesis rate is enhanced by amino acids, and myonuclei is increased by nucleotide. Therefore, this study investigated the effect of reloading combined with nucleoprotein supplementation including essential amino acids and nucleotide on muscle recovery. Rats were assigned randomly either to a control (CON), hindlimb unloading (HU), reloading after hindlimb unloading (HUR), and reloaded after hindlimb unloading with nucleoprotein supplementation (HUR+NP). Fiber cross-sectional area (FCSA), ribosomal protein S6 (rpS6), and number of myonuclei were examined in soleus muscle. FCSA, numbers of myonuclei, and the phospholyrated-rpS6 in the HU group were signifi cantly lower than those in the CON group. In addition, FCSA, numbers of myonuclei, and the phospholyrated-rpS6 were signifi cantly higher in the HUR group than in the HU group. Furthermore, FCSA, numbers of myonuclei, and the phospholyrated-rpS6 in the HUR+NP group were significantly higher compared with those in the HUR. These results suggest that reloading could promote recovery from atrophy, and nucleoprotein supplementation combined reloading treatment is effective to promote the recover from atrophy.

The purpose of this study was to clarify the effects of thermal therapy on pain and inflammation in the inactive phase of Rheumatoid Arthritis (RA) by using rats with adjuvant arthritis (AA). Ankle joint arthritis in the rats was induced by injection of complete Freund’s adjuvant (CFA). Thermal therapy (20 or 60 min/day, 5 days/week) was begun in the chronic phase of AA (4 weeks after CFA injection) and was performed by using a 3-cm-deep hot water bath at 40 ℃. The thermal therapy period was 4 weeks. Ankle volume, erythrocyte sedimentation rate (ESR), plasma concentrations of tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6), and mechanical hyperalgesia were determined. No significant changes in ankle volume and ESR were observed. Although mechanical hyperalgesia was aggravated temporarily just after thermal therapy, the longitudinal change in mechanical hyperalgesia was not affected throughout the thermal therapy period. The TNF-α and IL-6 levels were increased partly owing to the thermal therapy. Our data showed that thermal therapy was not effective as well as not noxious for pain and inflammation in the inactive phase of RA. Our data showed that thermal therapy was neither as well as not noxious for pain and inflammation in the inactive phase of RA.

The purpose of this study was to determine the neuromuscular activation patterns of the quadriceps femoris (QF) synergists including the vastus intermedius (VI) during squat movement. For 15 healthy men, surface electromyography (EMG) was recorded at VI, vastus lateralis (VL), vastus medialis (VM) and rectus femoris (RF) during the repetitive squat movements. The squat movement started upright posture. This movement consisted of eccentric (ECC) phase, isometric (ISO) phase at the bottom, and concentric (CON) phase with knee joint angle between 0° to 90°. The root mean square (RMS) of the EMG signals during three phases was calculated for knee joint angles ranging from 15° to 90°. Each ECC and CON phase was further divided into three subcategories. The RMS during squat was normalized by that of 15° to 40° during the ECC phase for all muscles. During the squat movement, a significant muscle-by-angle interaction in normalized RMS was found (P < 0.05). The normalized RMS of VI was signifi cantly higher than that of the VL and VM at all subcategories during ECC phase and ISO phase (P < 0.05). These results suggest that the VI plays an important role in the fl exed knee position during squat movement. This uncovered finding may help establishment of future effective therapeutic programs for dysfunction of QF related knee joint disorders.