Rotational hitting in baseball refers to the movement of the player’s body around a central axis, and in this case that axis is the spine, which includes the 24 vertebra, sacrum and coccyx.
The muscles invovled in rotating the player’s spine around during the launching phase are the external abdominal oblique, multifidus spinae and rotatores spinae muscles.
The rotatores spinae muscles are really unique muscles in that they lie beneath the multifidus and very close to the spine itself. There are 11 pairs of these muscles on both sides of the body and are located only in the thoracic region between each of the 12 dorsal vertebrae.
They originate from the superior and lateral aspect of the transverse process (tvp) of the vertebrae below and travel superior, medial and slightly posterior to attach into the laminae near the root of the spinous process of the vertebrae above.
While many aren’t aware of it, these tiny little muscles will cause your upper body to rotate to the opposite side, just like when you do oblique sit up crunches, when they contract. When you perform one and you rotate your chest to the left at the top of the exercise, the rotatores spinae muscles, along with the external abdominal oblique and multifidus muscles contract on the right side. The opposite happens when you perform a situp crunch to the right.
So these three muscle groups are involved with turning your upper body during the swinging of the baseball bat. They are also combined with hip rotator muscles to produce a very powerful rotational bat swing that I will talk about in another post.
Click here if you would like to learn more about rotational hitting
All the best.
Dr. Larry Van Such