BASEBALL BAT INERTIAL AND VIBRATIONAL CHARACTERISTICS AND DISCOMFORT FOLLOWING BALL BAT IMPACTS

This study examined the relationship between selected mechanical chara cteristics of aluminum baseball bats and sensations on the hands resul ting from impacts. Sixteen skilled male Little League baseball players held each of two bats while they were impacted at the following locat ions by baseballs at speeds of approximately 27 m/s: near barrel end, center of percussion (COP), distal node of the fundamental mode, and 4 in. toward the hands from the COP. Results of a questionnaire regardi ng annoyance and discomfort were correlated with selected bat characte ristics and vibrational characteristics associated with each impact co ndition. Results indicated that perceptions of annoyance and discomfor t were related to the level of excitation of the fundamental mode and first overtone mode and that annoyance and discomfort were less with i mpacts on die COP and fundamental vibrational node.