Re: Opening up
Once your son has brought the bat behind the head to the launch position, his lead-shoulder should not creep open as he prepares to initiate his swing. Allowing his shoulder to creep open prior to initiation results in a loss of power. However, as he is fully initiating his swing, it is the rotation of his shoulders that accelerates his hands in the swing plane and provides power for his swing.
Telling a batter to “keep his shoulder in-there” as he rotates his hips and “fires” his hands, results in an arm-dominated “slap” type hitter.
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