Injury Risk Analysis among Judo Athletes with Intellectual Disabilities.

The main aim of this study was to evaluate injury prevalence, incidence rate, and burden in judo athletes with intellectual disabilities (ID) who participate in international competitions. This retrospective cross-sectional study analyzed data from the past year for 182 judo athletes with ID. Data was collected using a self-reported questionnaire, adapted from previous research, that included questions about injuries impacting training or competition, injury type, mechanism, severity, diagnosis, and location on the body. The injury prevalence among judo athletes with ID occurred most often during training (68.2%) and primarily affected the lower extremities (35%). Age group and injury prevalence were significantly related (χ2=7.91; P=0.04), while gender, weight, and ability level were not. Results were closer to those previously reported for conventional judo, which is likely due to the lower practice intensity among judo athletes with ID. Injury prevalence was lower than in prior studies, but the incidence rates aligned when considering training time in judo athletes with ID. Injury burden analysis revealed that females had a lower burden than males, while older athletes experienced a higher burden than younger athletes. Most injuries occur during training, which is likely attributable to safety-focused competition rules.

Dynamic Control of Upper Limb Stretch Reflex in Wrestlers.

PURPOSE: The objective of this study was to clarify the characteristics of the upper limb stretch reflex in wrestlers. METHODS: Ten wrestlers and 11 control subjects participated in the study. The experiment was divided into two sessions. In the extension perturbation session, participants either relaxed or flexed the elbow when they felt a perturbation (abrupt elbow extension induced by a dynamometer). This was done 30 times by each subject for both sessions. In the flexion perturbation session, participants also relaxed or extended the elbow when they felt a perturbation (abrupt elbow flexion). During the tasks, the stretch reflex was monitored by recording the surface EMG activities of the right biceps and triceps brachii. The EMG reflex components were divided into three periods based on the time after the perturbation (M1, 20-50 ms; M2, 50-80 ms; and M3, 80-100 ms). The averaged background EMG activity just before the disturbance was subtracted from the EMG activity in each period. The resultant value was integrated to obtain reflex magnitudes of M1 to M3. RESULTS: For the triceps brachii, in the relaxation task, the wrestler group showed a significantly smaller value for M2 than did the control group. In the extension task, the wrestler group showed a significantly larger value for M3 than did the control group. There was no difference in M1 between the two groups. For the biceps brachii, there was no significant difference between any reflex components. CONCLUSIONS: Our results suggest that high-level wrestlers have specific characteristics of the long-latency stretch reflex in the triceps brachii that are modulated in a situation-specific manner.

Hand preference consistency and simple rhythmic bimanual coordination in preschool children.

This study examined whether strength of hand preference is associated with rhythmic bimanual coordination. 27 preschool children ages 4 to 6 years, identified as 10 right-, 8 left-, and 9 mixed-handed, were evaluated on accuracy and stability with a bimanual tapping task requiring intermodal matching. The primary hypothesis was that consistent right- and left-handers would have an advantage over mixed-handers given higher hemispheric maturation, possibly the corpus callosum, which may be the main interhemispheric communication conduit. A significant difference was noted among the three groups, with right-handers having higher accuracy and stability. This finding suggests that bimanual coordination in young children may be influenced by handedness, which may also be related to the development of interhemispheric communication.

A Kinematic Comparison of the Judo Throw Harai-Goshi during Competitive and Non-Competitive Conditions.

The purpose of this study was to compare the kinematics of kuzushi/tsukuri (KT) phases of the harai-goshi throw under competitive and non-competitive conditions. A third degree black belt subject served as the tori (thrower) for both conditions. Two black belt participants ranked as first degree and fourth degree served as the uke (faller) for the competitive and non-competitive conditions, respectively. Two video cameras (JVC 60 Hz) and a three dimensional motion analysis system (Vicon-Peak Performance Technologies, Inc., Englewood, CO) were used to collect and analyze peak velocity for the center of mass (COM) of uke and tori and peak angular velocity of tori's trunk (TAV). Data were smoothed using a 4(th) order zero lag Butterworth filter with a cut-off frequency set by the Peak software optimization technique. All variables were normalized by time as a percentage of the KT phase. In general, the COM directional velocity patterns were similar between conditions. Uke's defensive efforts during the competitive condition created differences in timing and magnitude of peak COM and TAV velocities. During competition, tori created larger peak COM velocities onto uke which indicated greater throwing power. Peak velocities for tori's COM were larger during the non-competitive condition since uke's resistance was minimal. Findings of the competitive condition suggested that mediolateral COM movement towards tori's pulling (left) hand can be an ideal set-up movement prior to execution. Tori's TAV was also greater during the competitive condition. Two distinct TAVs were observed, a counterclockwise TAV created by tori turning their hips during the entrance of the throw and a clockwise TAV created by the shoulders turning to complete the 180 degree body turn with the simultaneous leg sweep. It is thought that the counterclockwise rotation aids in producing a pre-stretch of trunk muscles which helps to create greater trunk rotation power. Key pointsCOM directional velocity patterns were similar between conditions and were consistent with the findings from previous kinetic studies.Uke's defensive efforts during the competitive condition created differences in timing and magnitude of peak COM and TAV velocities.Mediolateral COM movement towards tori's pulling (left) hand can be an ideal set-up movement prior to execuation.It is thought that the counterclockwise rotation aids in producing a pre-stretch of trunk muscles which helps to create greater trunk rotation power.

Hand preference consistency and eye-hand coordination in young children during a motor task.

Indications of earlier research are that individuals exhibiting a consistent hand preference are better coordinated on selected motor tasks than peers with inconsistent hand preference. The present study examined eye-hand coordination via inter- and intramodal matching behavior by handedness groups for 55 5- and 6-yr.-olds using the Pinboard Test. Analysis indicated the Consistent group scored better, leading to the speculation that children with consistent laterality may possess an advantage in interhemispheric communication, especially when the task requires coordination of both limbs.