The bat-head is the recipient of all the centrifugal force created in the body due to the rotation of the hips and spine along with the pushing and pulling action of the shoulders and arms. This is made possible by seven muscles in each hand and three muscles in each forearm holding the bat-handle with a firm grip. See Figure 4-45.
The hand grip muscles located in the hands are the Flexor Digiti Minimi Brevis, Opponens Digiti Minimi, Opponens Pollicis, Flexor Pollicis Brevis, Adductor Pollicis, Palmar Interossei and First Dorsal Interossei. See Figure 4-46.
The hand grip muscles located in the forearms are the Flexor Pollicis Longus, Flexor Digitorum Superficialis and the Flexor Digitorum Profundus. See Figure 4-47.
Now aside from holding the bat-handle with a firm grip, the hands other job is to supply direction to the bat from the initiation of the swing to contact with the ball.
This starts with the hands first directing the knob end of the bat inside the flight of the pitch towards the center of the ball as seen in Figure 4-48a. With all the explosive rotational movement taking place in the body, the bat-head is soon found lagging behind the hands as seen in Figure 4-48b.
The rotation of the body and the action of the shoulders and arms will help bring the bat-head around toward the contact point with the ball however, any movement in the wrist joints that was done prior to this point during the loading phase, such as that which would have taken place during the cocking of the wrists, will have to be restored, or returned, to a more neutral position at contact. See Figure 4-49.
This is because the best position for the wrists and hands to be in to transfer all of this explosive rotational power into the bat is square, or neutral, with respect to the forearms. This means the wrists are in a position without any flexion, extension, radial deviation (abduction) or ulnar deviation (adduction) or any combination of these.
Hand and wrist joints are at their strongest in this neutral position which is necessary to power the bat-head through the ball without being deflected. If the bat-head is deflected in any way when making contact with the ball due to a weak grip, loss of power will result. So, this is why it’s important to make contact with the ball with the hands and wrists in a neutral, or square, position.
Now as a side note here, if you look closely at Figure 4-50 below, you will notice that at contact, the player’s left forearm is in a pronated position and the right forearm is in a supinated position, but neither of these forearm positions affects the wrist joint.
If you recall during the loading phase, on the section of cocking of the wrists, we saw that pronation of the forearm occurs at the elbow joint and not the wrist and while we didn’t mention it there, supination of the forearm also takes place at the elbow joint and not at the wrist joint. Again, what is taking place in the elbow joints at contact does not affect the position of the wrist joints.
So, to finish up here, the ideal contact point is where the bat-head meets the ball at 90º from the direction of the pitch with the wrists in a neutral, or square, position. However, a margin of 15º degrees in either direction will still enable you to hit the ball with tremendous power.