Chronic ankle instability (CAI) causes impairment in proprioception, such as ankle joint position sense and plantar cutaneous sensation. Although plantar vibration stimulation may be effective as a ...means of en hancing proprioception, its efficacy remains ambiguous. This study aimed to clarify the immediate effects of plan tar vibration stimulation on healthy athletes and athletes with CAI. Eight healthy and eight CAI athletes partici pated in this study, and their joint position sense and cutaneous sensation were evaluated before and after the in tervention of plantar vibration stimulation or non-intervention, designed as a cross-over study. There were no sig nificant differences between the healthy group and the CAI group in both joint position and plantar cutaneous sensation. Also, there were no statistically significant changes in either group before or after the intervention. One possible explanation for the absence of differences between the healthy and CAI groups could be attributed to a high Foot and Ankle Ability Measure score. Neither group exhibited any changes in joint position or plantar cuta neous sensation following the vibration intervention. The frequency and amplitude of the vibration stimulation af fecting proprioceptors may be different, and the joint position and plantar cutaneous sensation of CAI groups may be comparable with those of healthy participants.
Ankle brace is commonly used to treat and prevent ankle sprain. Its main aim is to restrict supina tion of the ankle. However, some braces restrict ankle dorsiflexion and plantar flexion. In ...addition, loosening and loss of restriction after exercise have also been reported. The purpose of this study was to reveal if thin-type ankle brace for ankle sprain restricts ankle dorsiflexion and plantar flexion and its effect of exercise. Five male adults (average age of 30.8±5.2 years) were included in the study. Dorsiflexion and plantar flexion of subjectsʼright ankle was measured before and after wearing the brace, and before and after exercises. Exercises consisted of perform ing 20 times of calf raise, full squat, maximum vertical jump, and 5-minute running on a treadmill. Measurement was performed thrice, and their average was statistically analyzed between with and without the brace, and be fore and after each exercise. The results showed that there was no significant difference between all measured an gles of with and without the brace and before and after each exercise. Thin-type ankle brace for ankle sprain have been reported to restrict supination. Considering our results, this brace does not restrict ankle dorsiflexion and plantar flexion.
Slow cortical potentials (readiness potentials, RPs) reflecting the central programming of voluntary jaw movements were reported to appear preceding the movements. However, the current source ...producing the RP has not yet been localized. This study aimed to determine the cortical regions involved in the central programming of bilaterally symmetrical voluntary jaw movements, by locating the current source of the neuromagnetic counterpart of the RP (readiness field, RF). The RFs were found in the fronto-lateral region bilaterally, starting around 860 and 600 ms prior to the onset of masseter and digastric electromyograms (EMGs), respectively, and gradually increasing in magnitude to the peak within 100 ms before the EMG onset. Thus, the RFs appeared long before the reported onset of the excitability increase of pyramidal tract neurons. The current sources producing the RFs were located in the precentral gyrus bilaterally, with no bilateral differences in strength. We conclude that the primary motor cortex is involved bilaterally in central programming as well as in execution of bilaterally symmetrical voluntary jaw movements.
Methane stored in a natural lake sediment was investigated. Fresh sediment (8–25 cm in sediment depth) taken from Lake Biwa, Japan, contains 2.6 μmol/g d.s. (dry sediment) of CH4 on average. The ...sediment retained 0.31 μmol/g d.s. of CH4 even after air drying, which is 12% of the total CH4 in the fresh sediment. The higher the temperature for drying of the sediment, the smaller the amount of CH4 retained. The result of an adsorption experiment indicated that dried and completely degassed lake sediment adsorbs CH4. Clay particles in the sediment are possibly responsible for the adsorption of CH4. Methane observed in the fresh lake sediment was probably produced by bacteria in the past, then adsorbed on the sediment particles. Adsorption is another form of storage of CH4 in lake and ocean sediments, in addition to the well known forms of dissolved, bubble, and hydrate CH4.
This paper deals with cross-apparatus comparisons of an insulation design of electric power apparatus. Focusing on a gas insulated switchgear (GIS), an oil-filled transformer, a cable, and a ...capacitor, we summarize the different and common features of their insulation design on the basis of not only referring literatures but also the authors' experiences. The insulation design process has three evaluation steps. Each step optimizes its evaluation subject by considering the nature of an insulation medium or an insulation component, and the optimization result is different. However, it is common that the insulation design process has three steps without exceptions. The technology supporting the three steps is also common.
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