Updated: May 6, 2020
Casting the hands occurs when the hands move outside the front elbow elbow early. This causes the front elbow to move across the body, which in turn causes the hands and bat to swing across the plane of the pitch. This causes the player to hit in a small zone with very little room for error. When the hands start earlier this also means that you are committing to the pitch earlier, which can increase your chase rate as well. Casting the hands can also cause the barrel to release early, resulting in decreased bat speed at contact. The video below is a demonstration of casting the hands.
Notice how the lower body begins to rotate while the hands are staying back:
How to identify if you cast the hands: Use a camera view from behind home plate. Go to the toe touch position and look at the relationship between the lead hand and the lead elbow. The elbow should be closer to home plate than the hands (hands should be inside the elbow). Now advance the video to heel plant. Look at the the lead elbow and hand again. The lead elbow should still be closer to home plate.
In the example shown below, the top picture is showing the player hands staying inside the elbow. The bottom picture shows the lead hand moving outside the lead elbow too soon and hands are casting at the ball.
How is this related to the body?
There are several physical limitations which can cause the hands to cast.
1. Limited spine disassociation: the ability to separate the lower body from the upper body allows the player to initiate the swing with the lower body, allowing the hands to stay back.
This is best assessed through the pelvic rotation test. A limitation in this test can be due to a lack of hip or spine mobility, poor stability of the torso or poor coordination of the muscles that produce rotation.
2. Limited mobility of the lead shoulder to move across the body (horizontal adduction). This can prevent the player from creating a good separation between the hands and the body during the first move and can lead to the upper body/hands moving too soon.
3. Limited Wrist Mobility: wrist mobility is very important to being able to set the bat to allow the bat to release properly. If the player has difficulty with radial deviation, they might compensate by casting the hands.
4. Limited leg strength and power: if the lower body is lacking in strength and power this can cause the upper body to become over active in the swing. Our strength and power testing protocol can quickly identify how your body's primary power sources and if they are in balance. If the upper body is the dominant power source it is not uncommon to see the upper body dominate the swing or pitching motion.