THREE-DIMENTIONAL NECK KINEMATICS DURING BREAKFALL FOR OSOTO-GARI AND ITS ASSOCIATION WITH NECK FLEXION STRENGTH IN NOVICE JUDOKAS

The objective of this study was to demonstrate three-dimensional neck kinematics during breakfall motion for osoto-gari and to elucidate its association between neck strength in novice judokas. Twenty-one novice judokas volunteered to participate in this study. The Motion data was collected using a three-dimensional motion analysis technique. We found the neck motion occurs multidirectionally during the breakfall motion. In addition, the present result showed that the peak neck angular momentum the in frontal and horizontal plane accounted for approximately 30% of the peak neck extension momentum. Finally, there was no linear relationship between the peak resultant neck angular momentum and neck flexion strength, suggesting that neck strength in the single motion plane alone may not be associated with the risk of head injuries during judo

FEAR-IN DUCED CHANGES IN BREAKFALL Kl N EMATlCS FOR OSOTO-GARI IN NOVICE JUDOKAS

Awareness of the risk and incidence of injury during the breakfall movement may lead to a perceived fear, which could be detrimental to breakfall kinematics and may even increase the risk of judo-related head injuries. Therefore, our aim was to investigate the association between the perceived fear of the breakfall movement and breakfall kinematics for osoto-gari in novice judokas. Eight experienced and 10 novice judokas volunteered to participate in this study. Motion data of the breakfall for osoto-garl was collected using a three-dimensional motion analysis technique. We found a similar trend in the joint angle curve and peak neck extension momentum for novice judokas who perceived fear of the breakfall and for those who did not. The results indicate that perceived fear of the breakfall movement may not be associated with a novice judoka's breakfall motion skill for osoto-gari

KINEMATICS OF JUDO BREAKFALL FOR OSOTO-GARI

The purpose of this study was to identify kinematic parameters of breakfall for osoto-gari that can be distinguished between the experienced and the novice judokas. Eight experienced and four novice judukas volunteered to participate in the study. The motion data of the breakfall for osoto-gari were collected with a three-dimensional motion analysis technique. Our result demonstrated that there are significant differences in the hip movement pattern between the experienced and the novice judokas (

TRUNK BIOMECHANICS DURING BREAKFALL FOR OSOTO-GARI AND ITS ASSOCIATION WITH JUDO-RELATED HEAD INJURY RISK IN NOVICE JUDOKAS

The incidence of head injuries in novice judo practitioners is of increasing public concern in Japan. This study investigated the correlation between trunk biomechanics and judo-related head injury risk in novice judokas with the aim of developing effective injury prevention strategies. Thirty-one novice judokas were volunteered to participate the study. Three-dimensional motion analysis of the osoto-gari breakfall was performed. A multiple regression analysis was usedto test the correlation between trunk biomechanics and possible head injury risk. We found a significant correlation between the trunk COM velocity and the peak neck angular momentum (F= 13.29, df= 3, P\u3c 0.001, r= 0.77). The result suggests that controlling the trunk COM angular velocity may play an important role in judo-related head injury prevention for novice judokas

KINEMATICS OF JUDO BACKWARD BREAKFALL: COMPARISON BETWEEN NOVICE AND EXPERIENCED JUDOKAS

This study aimed to investigate the kinematic differences in judo backward breakfall between novice and experienced judokas. Eleven experienced and 13 novice judokas volunteered to participate in the study. Three-dimensional kinematic data were collected while participants performed five sets of backward breakfalls. We documented head-, neck-, trunk-, hip-, and knee-angle–time-curve profiles during judo breakfalls. The results showed significant differences in knee- and trunk-angle time curves, whereas no significant differences were found in head, neck, and hip kinematics between the novice and experienced judokas. These results suggest that motion of the lower extremity requires more attention during the learning of breakfall technique by novice judokas

BIOMECHANICS OF JUDO BREAKFALL FOR OSOTO-GARI IN ADOLSECENT JUDOKAS

Regardless of relatively higher head injury occurrence, few studies have investigated the biomechanics of a judo breakfall technique in adolescent judokas. The aim of the present study was to demonstrate biomechanical characteristics of the breakfall technique performed by experienced adolescent judokas during the “osoto-gari” throw by comparing it with those performed by experienced adult and novice adult judokas. Motion data from the breakfall technique were collected with a three-dimensional motion analysis method. No significant differences were observed in the hip and neck movement patterns between the novice and the adolescent judokas (p > 0.05), but not between the experienced adult and adolescent judokas. This suggests that regardless of experience, the breakfall skill level of the adolescent judokas is not similar to that of adult experienced judokas

Structure of RadB recombinase from a hyperthermophilic archaeon, Thermococcus kodakaraensis KOD1: an implication for the formation of a near-7-fold helical assembly

The X-ray crystal structure of RadB from Thermococcus kodakaraensis KOD1, an archaeal homologue of the RecA/Rad51 family proteins, have been determined in two crystal forms. The structure represents the core ATPase domain of the RecA/Rad51 proteins. Two independent molecules in the type 1 crystal were roughly related by 7-fold screw symmetry whereas non-crystallographic 2-fold symmetry was observed in the type 2 crystal. The dimer structure in the type 1 crystal is extended to construct a helical assembly, which resembles the filamentous structures reported for other RecA/Rad51 proteins. The molecular interface in the type 1 dimer is formed by facing a basic surface patch of one monomer to an acidic one of the other. The empty ATP binding pocket is located at the interface and barely concealed from the outside similarly to that in the active form of the RecA filament. The model assembly has a positively charged belt on one surface bordering the helical groove suitable for facile binding of DNA. Electron microscopy has revealed that, in the absence of ATP and DNA, RadB forms a filament with a similar diameter to that of the hypothetical assembly, although its helical properties were not confirmed

Long-term effect of external beam radiotherapy of optic disc hemangioma in a patient with von hippel-lindau disease

An 18-year-old woman with a 2-year history of hypertension and headache was diagnosed with noradrenalin-secreting bilateral adrenal pheochromocytomas with paragangliomas in the background of von Hippel-Lindau disease with family histories and a missense mutation, 712C to T (Arg167Trp) in the VHL gene. She had optic disc hemangioma in the left eye which gradually enlarged and caused serous retinal detachment on the macula in one year. Low-dose external beam radiation (20 Gy) was administered to the left eye using a lens-sparing single lateral technique. She underwent craniotomy for cerebellar hemangioblastoma at the age of 22 years and total pancreatectomy for multiple neuroendocrine tumors at the age of 24 years. In the 6-year follow-up period after the radiotherapy, the optic disc hemangioma gradually reduced in size and its activity remained low, allowing good central vision to be maintained. External beam radiation is recommended as a treatment option for the initial therapy for optic disc hemangioma