Baseball, America’s national pastime, is one of the more popular team sports played and watched in the United States (Porterfield, 2007). Nine players take the field to defend against the opposing team’s offense. The outfielders defend against the fly balls and ground balls that manage to get past the infield. The shortstop, first, second, third basemen, and pitcher compose of the infielders that defensively protect the infield area. After receiving the signal from the catcher, the pitcher prepares to pitch to outsmart the batter (Freeman, 2006). The catcher is often viewed as the defensive leader of the team due to the constant involvement with every pitch and the only player on the field with the ability to see the entire field of play (Freeman, 2006). One mistake by the catcher, however, could possibly mean the difference in the outcome of the ball game. Opposing the defense, the offense consisting of both batters and base runners, strive to create as many opportunities as possible to score runs in order to win the ballgame. With runners on base, the possibility of scoring greatly multiplies, particularly if runners, via base hits and/or stealing bases, reach second or third base. Stealing bases is one of the strategies employed by offenses to advance runners into scoring position (Freeman, 2006). Although suppressing runners from stealing is two fold due to the involvement of both pitcher and catcher, the catcher plays a more pronounced role in effectively catching a base stealer. How quickly a catcher is able to release the ball, accurately throw, while throwing with a fast velocity, determines the successfulness of the catcher (Freeman, 2006). The baseball catcher throws more frequently than any other player on the field and is often graded heavily on their throwing ability by professional scouts (Walter, 2002). A plethora of studies analyze baseball pitchers’ throwing mechanics, however, very limited research centers on the catcher. It is with this understanding that the throwing motion of the baseball catcher also be studied.
Background
Defensively, pitchers and catchers collectively manage the defensive rhythm of the game in order to thwart runners from attempting to steal bases to advance into scoring position. The catcher’s involvement in every pitch can potentially influence game outcomes, thus making this position one of the most rigorous in the game of baseball (Plummer & Oliver, 2013). Runners are far more likely to score from second base than from first base (Sheehan, 2004). Therefore, one of the many responsibilities of the catcher is to impede runners from advancing into scoring position by means of a stolen base (Bail, 2005). A catcher must receive the pitched ball in a squatted position and throw the ball to second base in approximately 2 seconds in order to catch a base stealer (Fortenbaugh, Fleisig, & Bolt, 2010; Scala, 2009; Walter, 2002). The distance between home plate and third base measures 27.4 meters, identical to the distance between home plate and first. However, the distance increases to 38.8 meters from home plate to second base, consequently resulting in base stealing occurring more commonly between first and second base.
When the catcher notices a runner attempting to steal second, the catcher must catch the ball thrown by the pitcher, transfer the ball smoothly and “cleanly” into the throwing hand, while concurrently begin the throwing motion to deliver the ball to second base (Fortenbaugh, Fleisig,
& Bolt, 2010; Plummer & Oliver, 2013). Three commonly seen throwing motions catchers used are throws from the knee, the traditional throw down, and the pitch out. It is assumed amongst the baseball community that the pitch-out would be the quickest and most ideal method to throw-out a base runner attempting to steal second base (Fortenbaugh, Fleisig, & Bolt, 2010). However, if the pitch-out is executed, a ball is called and an unfavorable count results. Conceivably, studying the motions of the three throws can provide coaches a clearer picture as to which motion to utilize to increase the chances of successfully preventing stolen bases.
Purpose
The purpose of this study was to investigate and understand the joint kinematics of the three throwing motions: throwing from the knees, traditional throw down, and pitch out, when throwing to second base. Furthermore, comprehending throwing motion kinematics will provide insight to the effects on performance and potential improvements made to enhance performance.
Hypothesis
1. The three throwing motions would have significantly different throwing kinematics.
2. The performance results (ball velocity, pop time, and time to second base) would show significant differences between the three throwing motions.
Limitations of the Study
Delimitations
The study was delimited to the following:
1. Participants were active, healthy, professional baseball players in Taiwan’s professional baseball league.
2. Specific instructions were given to the participants in order to standardize testing protocols.
3. The throwing order protocols were randomly assigned to avoid an ordering effect.
Limitations
The study was limited by the following:
1. An indoor, controlled testing setting without environmental influences such as wind, sunlight, dirt ground, etc.
2. Participants may vary in their respective warm-up techniques and routines.
3. Participants may vary in their respective throwing mechanics 4. Variations in participant’s catcher’s mitt.
5. Variation in participants shin guards and foot wear.
6. Absence of catcher’s facemask and chest protection gear.
7. Variation in velocity and location of the pitches delivered to the catcher.
8. The absence of a runner stealing second base.
Definition of Terms
Catcher – one of nine players on the field. Crouches behind the batter’s box and in front of the home plate umpire. Receives the thrown ball from the pitcher.
Pitcher – one of nine players on the field; throws from the pitcher’s mound to the catcher to initiate each play.
Base-stealing / Stolen bases – a strategy utilized to advance base runners into scoring position
Scoring position – a runner is on second or third base
Throwing from the knees – a throwing method to deliver the ball to second base by throwing the ball from a kneeling position.
Traditional throw down – a throwing method to deliver the ball to second base. The catcher receives the ball from the pitcher, transfers the ball to the throwing hand, hops and turns the body perpendicular to second base, and continues to step and throw the ball to second base.
Pitch out – a throwing method to deliver the ball to second base. Prior to receiving the ball from the pitcher, the catcher takes a side step to the left hand’s batter box, catches the ball from the pitcher while stepping forward, transfers the ball to the throwing hand, and continues to step and throw the ball to second base.
Ball velocity – the velocity (meters per second) of the ball measured from the moment the ball is released from the catcher’s hand.
Pop time – the time duration between: the moment the ball is caught to the ball leaving the catcher’s hand.
Time to second base – the time duration between: the moment the ball enters the catcher’s glove, leaves the catcher’s hand, and travels 38.795 meters to second base.
Stride Length – the distance between the heel of the front foot and the heel of the rear foot.
Kinematics – to analyze the human body in the action of throwing a baseball to second base via three throwing motions. Angular velocities and joint angles parameters are measured, however force parameters are excluded.