Comparison of movement while infielders catch a grounder at various skill levels of baseball:

from the view point of caching point and upper limb that catches a ball

Abstract

    The purpose of this study was to compare the movement of upper limb that catches a ball while infielders catch a grounder at various skill levels of baseball. This study included amateur baseball players (high level group) and college baseball players (middle level group). We photographed their movement as fielding the grounder by a high-speed camera (300Hz). The 3-dimensional coordinates of the segment end-points of body, glove, and ball were calculated by DLT method. The calculation items included the catching position, adduction/abduction angle of left shoulder joint, horizontal adduction/abduction angle of left shoulder joint, flexion/extension angle of left shoulder joint, flexion/extension angle of left elbow joint, and palmar flexion/dorsal flexion angle of left wrist joint.
    The result of this study was concluded as follows.
    1) There was no significant difference in the catching position between both groups.
    2) The adduction and horizontal adduction of left shoulder joints in the high level group were significantly smaller than the middle level one (p<0.05).
    3) The flexion of left shoulder joint in the high level group was significantly smaller than the middle level one (p<0.05).
    These movement was caused by the timing of right foot grounding and movement of lower limb and trunk.