Posted by: Dave (nytino20@aol.com) on Thu Feb 1 08:07:08 2007

Title: EJ711617 - Training the baseball hitter: what does research say? Guided too long by folklore, baseball batting has become a science.
Abstract: Former baseball star Jim Lefebvre (1983) claimed that hitting a baseball may be the most talked about but least understood skill in all of sports. Historically, hitting instruction has been based on intuitive thinking by "hitting gurus," rather than on scientific fact, which has contributed to this lack of understanding (DeRenne, Stellar, & Blitzbau, 1993). Compared to other sports, baseball has lagged in regard to the application of science to the development of the swing and training methodology.Although athletes and coaches have many hitting drills to choose from, few of these drills are grounded in science. A thorough understanding of the mechanics of the baseball swing is critical to formulating a sound training methodology. Therefore, the purpose of this article is to use previous studies to describe proper swing mechanics and to provide a few examples of drills that could be used to train these mechanics. However, the concepts of bat velocity and bat quickness must be considered before any discussion of swing mechanics. Recognizing the difference between these two, often misunderstood, concepts is a prerequisite for understanding the mechanics of the baseball swing.[FIGURE 1 OMITTED]Bat Velocity and Bat QuicknessBat velocity is the speed at which the bat head is traveling at the moment of contact (Stellar, House, DeRenne, & Blitzblau, 1993). Bat velocity is important for several reasons. According to the equation, force equals mass times acceleration, the greater the velocity of the bat at contact, the greater the force that can be imparted to the ball and the farther the ball will travel once it is hit (Hamilton & Luttgens, 2002). In addition, if energy equals one-half mass times velocity squared, a bat swung with more velocity will result in greater energy imparted to the ball. In short, the higher the velocity of the bat at contact, the higher the velocity of the batted ball (Adair, 1990). This is true both for wooden bats and aluminum bats (Crisco, Greenw; ald, Blume, & Penna, 2002).Bat quickness is the time it takes to move the bat head from the launch position to contact with the ball, measured in seconds (Hay, 1993). The relationship between bat velocity and bat quickness is usually inverse in effect (Stellar et al., 1993). That is, players who exhibit high bat velocities tend to have poor bat quickness (high swing times). The bat quickness of major league hitters has been calculated to be 0.14 to 0.15 of a second in contact hitters, and 0.17 to 0.18 in power hitters, demonstrating the inverse relationship between the two performance variables (Stellar et al., 1993). This relationship has been attributed to changes in decision time (Hay, 1993). Decision time is the amount of time the hitter has to read the pitch and decide if, when, and where to swing the bat. As bat quickness improves, decision time increases, and the chance of making a correct decision increases.Variation in swing mechanics can account for much of the observed relationship between bat velocity and bat quickness. For example, as bat wrap increases, bat velocity increases, but bat quickness becomes slower. Bat wrap refers to the degree to which the bat points toward the pitcher in the launch position (figure 1). The greater the wrap, the farther the barrel of the bat must travel to get to the contact zone. The greater distance traveled results in higher swing times (slower bat quickness), but the additional time allows the hitter to generate more bat velocity. Varying the extension of the lead elbow has a similar effect. In other words, as extension increases, so does the length of this segment as a lever. The end result is a wider radius from launch to contact and a subsequent increase in angular velocity and swing time (Bunn, 1965).[FIGURE 2 OMITTED]It is important to realize that high bat velocity does not necessarily mean a more productive hitter. This can be confirmed by the lower batting averages typically observed in power hitters. Similarly; , great bat quickness with poor bat velocity will most likely result in poor power statistics such as extra base hits and slugging percentage. A hitter must combine bat velocity and bat quickness in order to maximize productivity. Players who have great bat velocity and outstanding bat quickness hit for both power and a high average. These players are the superstars of the game. There are, of course, other factors that play a role in hitting productivity. These include, but are not limited to, visual skills, pitch selection, and confidence. Due to the limited scope of this article, these factors will not be discussed.Improving bat velocity without compromising bat quickness can be accomplished with strength and power training. That is, the associated musculature is trained to contract more forcefully and rapidly without any changes in swing mechanics (i.e., increased bat wrap). Using electromyography, Shaffer, Jobe, Pink, and Perry (1993) explored the muscle activation patterns of various muscles during the baseball swing in professional baseball players. The authors concluded that hitters should emphasize the abdominals and muscles of the lower back due to the high muscle activity observed in these muscle groups throughout the swing.Although most abdominal and lower back exercise would benefit the hitter, those exercises that involve twisting of the torso are more specific to the movement patterns of the baseball swing (Garhammer, 1983). Once a base level of local muscle strength and endurance has been established via various crunches and lower back exercises, hitters can begin to incorporate resistance with rotation. An example of such a drill is the hitter's toss, a rotational plyometric exercise depicted in figure 2. In this drill, the hitter loads the muscles of the trunk and then throws the medicine ball as forcefully as possible while mimicking the mechanics of the swing as best as possible. Theoretically, if the ability of the musculature to contract rapidly; increases, and swing mechanics remain unchanged, both bat velocity and bat quickness could be improved concurrently.Baseball Swing MechanicsIn order to simplify data analysis, the study by Shaffer et al. (1993) divided the swing into four separate phases: the wind-up, pre-swing, swing, and follow-through. Because of its effect on these four phases, the hitter's stance before initiating the swing will also be discussed.StanceThe manner in which a hitter stands in the batters' box before the pitch is a subject that lacks scientific evidence (Hay, 1993). Although hitters' stances are individualized, it should be noted that most major league hitters have certain characteristics in common. Identifying these characteristics is important because problems with the stance can lead to problems with the swing. The first characteristic of the major league stance is dynamic balance. This means that the head is over the center of gravity and the center of gravity is equidistant between the balls of the feet. If the hitter is unbalanced, the hitter will not be able to create a base of support to execute the proper swing mechanics (DeRenne et al., 1993). The second characteristic of the major league stance involves the position of the head. The head should be facing the pitcher in such a way that the batter can see the pitcher with both eyes. In addition, there should be minimal tilt of the head so that eyes are parallel with the ground. Starting with the head in this position will help to keep the distance between the chin and the lead shoulder relatively constant throughout the swing (DeRenne et al., 1993).[FIGURE 3 OMITTED][FIGURE 4 OMITTED]The third characteristic is rhythm. Most major league hitters incorporate rhythm while waiting for the pitch in their stance (Hudgens, 1997). Rhythm keeps the body free of tension and aids in the timing of the pitch. The hitter's rhythm starts with large movements and slows down to a smaller movement just before the swing. Most successful ma; jor league hitters slow down their movement or rhythm just before they stride. Videotape and mirrors are useful tools for improving the stance. Hitters may think they are incorporating balance, proper head position, and rhythm in their stance, but on seeing their stance in a practice or game situation, they may be surprised to observe otherwise.Wind-up PhaseThe wind-up phase begins as the lead foot leaves the ground and ends when it returns back to the ground (figure 3). This phase may also be thought of as the stride. The stride is a step taken by the hitter in the direction of the pitcher (Bennett & Yeager, 2002). The stride is a preparatory movement that allows the hitter to generate linear momentum in the direction of the pitch. This momentum is desirable unless the hitter is unable to maintain balance (DeRenne et al., 1993). As the stride takes place, the hands, shoulders, and hips also move. The hands move back toward the rear shoulder until they are located over or behind the rear foot, and the shoulders and hips rotate inward (Welch, Banks, Cook, & Draovitch, 1995).[FIGURE 5 OMITTED]The stride must be completed before any other forward movement is made in the swing. In other words, rotation of the torso toward the pitched ball should not take place until the stride heel makes contact with the ground (DeRenne et al., 1993). The baseball swing is initiated, not by the back leg as many coaches teach, but by the front heel making contact with the ground (Welch et al., 1995). No further linear movement of the body should occur once the stride heel lands. If the lead foot is not down before the pitched ball is half way to home plate, the hitter will not have enough time to rotate the trunk, shoulders, and bat into contact with the ball.The length of the hitter's stride also affects his or her reaction time. Stride length is directly proportional to linear body movement, therefore a longer stride will move the head and eyes that much closer to the pitched ball. For; example, if an 85 miles-per-hour pitch is thrown to a hitter with a five-inch stride, the same pitch will have an effective speed of 88.5 miles-per-hour to a hitter with a 15-inch stride. A short stride also increases the chance of the stride being consistent every pitch (Hay, 1993).The "command soft-toss drill" is an effective means for teaching the stride (figure 4). During the soft toss, the coach provides a verbal cue of when to stride. Once the stride is down, the coach waits and then tosses the ball so that the hitter can hit it into a net. The objective of the drill is to separate the stride from the swing, which teaches the hitter to stop the linear movement once the stride foot has made contact with the ground. This drill also emphasizes the importance of an early stride (timing) and allows the coach to provide feedback in regard to the length and direction of the stride.[FIGURE 6 OMITTED]Before ending this discussion of the stride, the concept of inward turn must be addressed. Ted Williams (1971) called the inward turn a "hip cock" and compared it to a pendulum. It is a movement of the hips during the stride so that the hitter can countermove them more efficiently during the swing. Scientific research supports Williams' intuitive reasoning. Welch et al. (1995) reported that hitters rotated their upper bodies in the opposite direction of the swing starting with the arms and shoulders, followed by the hips.There is a difference of opinion as to when the inward turn takes place. One study reported that the inward turn occurs while the hitter is shifting his or her weight against the rear leg before the stride (Welch et al., 1995). Other sources suggest that the inward turn reaches its maximum during the stride (Hay, 1993)

this was taken from: http://www.eric.ed.gov/sitemap/html_0900000b8034cd9c.html

The link is hard to get to work. You have to copy and paste it into address bar and then hit stop as soon as it loads because it sends you somewhere else. This is why I posted the entire message.