A biomechanical comparison of baseball pitching from the mound versus the flat ground, focusing on ball velocity and motion of the lower limbs and trunk
野球投手におけるマウンドと平地からの投球のバイオメカニクス的比較:投球速度および投球動作中の下肢および体幹の動作に着目して

Masahiro Kageyama, Chiharu Suzuki, Masafumi Fujii, Hiroki Nakamoto, Tomohito Wada, Akira Maeda
2016 Taiikugaku kenkyu (Japan Journal of Physical Education Health and Sport Sciences)  
A biomechanical comparison of baseball pitching from the mound versus the ‰at ground, focusing on ball velocity and motion of the lower limbs and trunk. Japan J. Phys. Educ. Hlth. Sport Sci. 61: 517 535, December, 2016 AbstractThe purpose of this study was to clarify the proˆles of lower limb and trunk motion during baseball pitching in relation to diŠerences between the mound and the ‰at ground, and to determine the motion characteristics while pitching from the 2 locations. The subjects
more » ... 12 baseball pitchers (age 18.6±2.5 yr, height 173.4±6.5 cm, weight 74.7±11.0 kg) who belonged to high school or university baseball teams. Three-dimensional positions of 36 re‰ective markers attached to each subject were tracked by an optical motion capture system (Mac3D System) with 12 cameras. The ground-reaction forces (GRF) of the pivot and stride legs during pitching were determined using 2 multicomponent force plates. Pitching motion was divided into two phases: phase 1 was deˆned as the period from when the knee of the stride leg reached maximal height (MKH: 0time) until the point when the stride foot made contact with the ground (SFC: 100time), while phase 2 was deˆned as the period from the SFC until the point when the ball was released (REL: 200 time). Ball velocity was measured using a radar gun. The results were as follows: 1) The maximum and average ball velocities were signiˆcantly higher when pitching was performed from the mound than from the ‰at ground (p<0.05). 2) Hip/knee ‰exion angles and hip abduction/extension angular velocities on the pivot leg were signiˆcantly greater for mound pitching than for ‰at ground pitching, and the hip/knee extension angle and hip adduction/internal rotation/‰exion angular velocities on the stride leg were signiˆcantly greater for the former (p< 0.05). 3) The GRF of the stride leg was signiˆcantly greater for mound pitching than for ‰at ground pitching (p<0.01). 4) Upper torso and pelvis angle/angular velocities at SFC and the maximum pelvis, upper torso and trunk tilt angular velocities were signiˆcantly greater for mound pitching than for ‰at ground pitching (p<0.05). The present results indicate that baseball pitchers show biomechanical diŠerences in the kinematic and kinetic proˆles of the trunk and lower limbs when pitching from the mound in comparison with the ‰at ground, and that high school or collegiate baseball pitchers can increase their pitched ball velocity by using the height of the mound.
doi:10.5432/jjpehss.15093 fatcat:5ucazlktcjczllydsp3ezs6wiy