Medical Definition of Z LINE. : any of the dark bands across a striated muscle fiber that mark the junction of actin filaments in adjacent sarcomeres.Britannica.com: Encyclopedia article about Z line.efinition of Z LINE. : any of the dark thin bands across a striated muscle fiber that mark the junction of actin filaments in adjacent sarcomeres. ADVERTISEMENT.
The average fb speed in the MLB is 91-92ish. Catchers compete with this when trying to throw down a runner at 90ish. The average throw speed from third base is 80 MPH. As for the rest of the positions I am not sure of the exact average, but it is not as fast or faster than pitch speed.
(j7) Sato 160 2010 - AP article 8/26/2010 Baseball: Sato throws fastest pitch by Japanese player+ Yakult Swallows right-hander Yoshinori Sato set a new record by a Japanese pitcher when he recorded a fastball at 161 kilometers per hour in a game against the Yokohama BayStars on Thursday.