How do dodgeball holding techniques influence ball velocity and joint torque generation of the upper body segments in developmental children?

Abstract

Children often hold a large ball with their fingers, palm, and flexed wrist when throwing arm holding (AH). The study questions were whether kinematic differences between AH and hand grasping (HG) are attributed to kinetic variables and ball velocity. Relative time series of the joint angles, joint torque generated by the upper body segments, and centrifugal force were compared between 40 AHs and 84 HGs among children aged 6–12 years old using statistical parametric mapping. Although internal rotation torque and adduction torque generated by the shoulder joint were greater for HG, the maximal ball velocity was not different between HG and AH. Wrist and elbow joint torque were not significantly different regardless of greater wrist and elbow joint flexion due to ball holding in AH. AH utilized more centrifugal force by increasing angular velocity at the latter phase of the throwing motion. Given these, choosing either AH or HG was not necessarily determined by ball graspability. Proximal joint torque with the centrifugal force at the latter phase of the throwing motion contributed to AH showing an equivalent maximal dodgeball velocity with HG in developmental children.