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.
Joel ZUmaya threw the fastest pitch ever in a major league baseball game. He threw a fastball at 104. 8 miles per hour at McAfee Coliseum in Oakland on Tuesday, October 10, 2006. The Detroit Tigers were playing the Oakland Athletics in Game 1 of the 2006 American League Championship Series.