Comparing the seoi-nage skill of elite and non-elite judo athletes.

Seoi-nage performance requires a high level of skill and proficiency. The aim of this study was to compare the motor planning, regulation, and control skills of elite versus non-elite seoi-nage judo athletes. Twenty subjects (10 elites and 10 non-elite) performed the three-phase seoi-nage skills of unbalancing, positioning, and throwing while an optical motion capture 3D camera monitored their shoulder, pelvis, hip, and knee joint movements to calculate their force magnitude and direction. Elite athletes performed better than non-elite athletes in terms of the shoulder (247.4° vs. 208.3° in Event 4) and pelvic (235.4° vs. 194.4° in Event 4) rotation, tilt angle (15.13° vs. - 0.74° in Event 4) characteristics, as well as hip (136.1° vs. 125.0° in Event 4) and knee joint (124.0° vs. 120.8° in Event 3) flexion-extension angle. Compared to non-elite athletes, elite athletes also showed more controlled force and movement in all bodily areas. These results can help to guide the development of seoi-nage skills as judo athletes advance from the non-elite to the elite level.

A Feasibility Study of Kinematic Characteristics on the Upper Body According to the Shooting of Elite Disabled Archery Athletes.

The purpose of this study is to compare and analyze the kinematic characteristics of the upper limb segments during the archery shooting of Paralympic Wheelchair Class archers (ARW2-second wheelchair class-paraplegia or comparable disability) and Paralympic Standing Class archers (ARST-standing archery class-loss of 25 points in the upper limbs or lower limbs), where archers are classified according to their disability grade among elite disabled archers. The participants of this study were selected as seven elite athletes with disabilities by the ARW2 (n = 4) and ARST (n = 3). The analysis variables were (1) the time required for each phase, (2) the angle of inclination of the body center, (3) the change of trajectory of body center, and (4) the change of the movement trajectory of the bow center by phase when performing six shots in total. The ARW2 group (drawing phase; M = 2.228 s, p < 0.05, holding phase; M = 4.414 s, p < 0.05) showed a longer time than the ARST group (drawing phase; M = 0.985 s, holding phase; M = 3.042 s), and the angle of the body did not show a significant difference between the two groups. Additionally, in the direction of the anteroposterior axis in the drawing phase, the change in the movement trajectory of the body center showed a more significant amount of change in the ARW2 group than in the ARST group, and the change in the movement trajectory of the bow center did not show a significant difference between the two groups.

A Case Study on Curling Stone and Sweeping Effect According to Sweeping Conditions.

The purpose of this study was to use the same ice temperature and air temperature as the Pyeongchang Curling Stadium by using an Ice Chamber. Then, launch the stone at the same speed, and move according to the sweeping conditions (perpendicular to the axis of motion, along the axis of motion) of male and female elite curlers. The aim is to provide sports science information required for curling athletes by analyzing the distance of the stone, the change in the speed of a moved stone, the change in broom acceleration, and athletes' muscle activity. The results of experiments conducted on four male and four elite female curlers are as follows. Under gender, the stone's movement distance was long after the sweeping of male athletes, and the speed of the stone was not different according to the conditions. The broom's acceleration did not show a difference in both the sweeping condition and the athlete's gender condition, and the muscle activity did not show a significant difference in both the sweeping condition and the gender condition. In summary, it is thought that male athletes moved the stone farther by raising the ice surface temperature by vertical load than female athletes. Also, there was no statistically significant difference in muscle activity results, but it was found that there was a specific pattern of muscle activity in the pushing and pulling motions during the sweeping of male and female athletes. It is expected to be used as primary data.