Lead Arm - From the Cocked Position to the Follow-Through
When the throwing arm arrives in the cocked position, the lead arm is bridged – the lead elbow is up at shoulder height and pointing toward home plate. Simultaneous with the turning of the hips and shoulders, the lead elbow is pulled down to the side of the body. This is called the tuck and it helps to generate the speed with which the hips and shoulders turn. The glove remains in front of the elbow during the tuck and is held close to the body. After the follow-through, the lead arm should be brought back in front of the body with the glove up to protect the pitcher from hit balls. A good defensive position after the pitch is often lacking at all levels.
A problem for many young pitchers is the habit of throwing the glove behind the body during the follow-through. This is easy to spot when looking for it and can easily be corrected with practice.