2019 Volume 64 Issue 1 Pages 169-185
In table tennis rallies between elite players, rapid swing movements must be achieved in a posture that is difficult to maintain while maintaining body agility. Players are required to have both a high racket speed and quick swing ability. On the other hand, a large movable range during a back swing may be disadvantageous for realizing a rapid, high-speed swing. Against this background, we sought to investigate the shoulder and torso joint movement characteristics of elite table tennis players when performing topspin forehands with 3 types of body movement, and to clarify the relationship between the maximum range of motion and swing skill. Ten male elite players participated in this experiment. Each performed 3 types of stroke trial (chance ball task, step over task, and step around task) and the active ranges of motion in the shoulder and torso joints (ROM trial) were measured. The three-dimensional coordinates of body landmarks (thorax, pelvis, and dominant humerus) and the racket during measurement were acquired using an optical motion capture system. The relationship between the maximum backward rotation angle at the shoulder and torso joint, the racket speed at ball impact, and the start time of the forward swing in each segment or joint were investigated. There was no significant difference in the maximum horizontal abduction angle at the shoulder joint between ROM trial and stroke trial (p > 0.2). Maximum torso backward rotation angle in ROM trial was significantly larger than that in the stroke trial (p < 0.05). In ROM trial and each stroke trial, the anatomical and functional flexibility of the shoulder and torso joints did not positively affect the racket speed and swing time. Rather, performance tended to be better during smaller backswings. Therefore, table tennis players require muscle strength or a technique that increases joint stiffness during racket swings.
