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Bat design and ball exit velocity in baseball: Implications for player safety - page 6 / 12

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Bat design and ball exit velocity in baseball: Implications for player safety

R.L. Nicholls* , B.C. Elliott & K. Miller

University of Western Australia

Velocity component

Metal (ms-1)

Wood (ms-1)

p

Bat tip (X)

37.46 ± 3.19

34.09 ± 3.86

0.0005*

Bat tip (Y)

1.09 ± 5.34

-2.69 ± 4.52

0.02

Bat tip (Z)

8.70 ± 5.74

6.81 ± 8.05

0.221

Bat tip (resultant)

39.39 ± 3.24

36.39 ± 3.25

0.0005*

Table 2: Instantaneous bat tip linear velocity (m/s) for wood and metal baseball bats (0.005 s prior to ball contact)

  • *

    p < 0.01

Cassidy and Burton (1989) indicated 400 ms is required for a pitcher to complete a reactive movement to avoid being struck by the batted ball. This corresponds to a ball exit velocity of approximately 42 m/s. Mean ball exit velocity from wood bats in this study (Table 4) was 40.8 m/s. This finding supports the use of wood bat exit velocities as a “gold standard” to determine permissible bat performance in baseball. On July 19, 1999, the US National Collegiate Athletic Association (NCAA) Baseball Rules Committee ruled ball exit velocity of 93 1 mph (41.57 m/s) was the certifiable limit for all metal bats used in college baseball. This ruling was based on BBV tests conducted on solid wood bats, considered an acceptable standard as they have been in use since the inception of the game. Our results suggest ball exit velocity from wood bats swung by live hitters is within, but at the upper limit of, human reaction time for defensive players. The finding that average exit velocity from metal bats was 43.98 m/s (98.95 mph), and as high as 120.97 mph, indicates a high potential for impact injury to fielding players.

Angle

Metal (deg)

Wood (deg)

p

TILT

120.53 ± 3.59

118.57 ± 7.26

0.176

TRANS

359.37 ± 13.93

338.89 ± 7.66

0.0005*

Table 3: Bat orientation (deg) at the instant 0.005 s prior to ball contact for wood and metal baseball bats.

  • *

    p < 0.01

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