Avulsion fracture of the tubercle of the fifth metatarsal bone is called "Geta fracture" in Japan. In this study, we investigated the therapeutic results of fixation using plaster casts in sixteen patients in whom the displacement of the fragment was 1.7 ± 0.8mm（range: 0.3－3.2mm）on X-ray imaging. This method allowed early recovery of weight bearing walking and activities of daily life were not markedly affected by this method. Furthermore, this method may shorten the time required for healing the fracture. Thus, we describe the usefulness of this conservative treatment for avulsion fracture of the fifth metatarsal bone.
We studied the electrophysiological effects of physical exercise on somatosensory information processing by comparing a groups of individuals practicing high intensity physical exercise using lower limbs（playing soccer; exercise group）to a group of sedentary subjects with no exercising habit（non-exercise group）. Event-related potentials（ERPs）were recorded using somatosensory stimulation at the tibial nerve（lower limb）and at the median nerve（upper limb）separately under oddball task conditions. N140 amplitude for upper limb task was greater in the exercise group than in the non-exercise group. P300 latency for lower limb task was shorter in the exercise group than in the non-exercise group. However, no difference in P300 latency for upper limb task was observed between the two groups. P300 amplitudes for lower limb task were also greater in the exercise group than in the non-exercise group, but P300 amplitudes for upper limb task were not different between the two groups. These results indicate that training of the lower limbs results in a difference in amount of somatosensory input following continuous physical exercise, and affects P300 latency and amplitude of the somatosensory ERPs. The findings suggest that using the lower limbs and upper limbs in daily exercise enhances somatosensory cognitive function.
We studied the effects of kinesiotaping（KT）on somatosensory input by comparing KT with non-elastic white taping（WT）, using somatosensory evoked potentials（SEPs）following tibial nerve stimulation. Five healthy right-handed males and females（mean age 22.6±0.54 years）were studied. P1-N2 amplitudes were increased under both KT and WT conditions compared to non-taping condition, and were significantly greater in KT than in WT. However latencies of SEP components were not different between the two taping conditions. These results indicate that KT enhances somatosensory inputs from peripheral limbs to the somatosensory cortex, due to the elastic characteristics.
Immobilization using non-elastic tape and a plastic cast induced degeneration of muscle fiber in the mouse soleus muscle (Fig. 1). We call this degeneration by wave-like structure in this report. The incidence of the wave-like structure increased with disuse time. Actually, about 65% of muscle fibers formed the wave-like structure after 7 days of immobilization on average. It was confirmed by the TUNEL (Terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin Nick-End labeling) method that the nuclear DNA of the wave-like structure was not fragmented. Therefore, the relationship between the wave-like structure and segmental necrosis is not clear, because the nuclear DNA of the segmental necrosis part is fragmented (Oka et al. 1996). However, we propose that the wave-like structure is a sensitive marker of morphological change induced by disuse.