At the start of every baseball season, newly arriving or returning pitchers are excited to show off new pitches or speed that was gained in the offseason. However, giving attention to the muscles that affect technique is often ignored. Poor technique can lead to injuries in pitchers like tearing their Ulnar Collateral Ligament or UCL; one of the elbow’s main stabilizing ligaments. This post is to educate, to provide information to prevent injury and perform better.
To know which muscles are needed to pitch correctly you need to understand the steps of a pitch. Beginning with the wind-up, the pitcher steps back with the front leg placing the back foot on the rubber of the mound, the pitcher’s body is turned sideways to the target and ends with their hands separating and front leg bent high up. This step uses the quadratus lumborum and obliques (muscles along you side and low back), allowing side bending and rotating towards the same and opposite direction respectively. The next is the stride phase, the pitcher moves their front foot toward home plate while bringing their arms further away from each other. This ends with the same foot touching the front of the mound pointed towards home plate. The muscles here separate both arms and control the movement. These muscles are the rhomboids, middle and lower trapezius (muscles in you upper back). The quadriceps in this situation provides a base of support, allowing the muscles of hips to create force in the next step. The next phase, the cocking phase, requires the pitcher to rotate their hips and trunk towards home plate while the throwing arm rotates outwards at the shoulder and lifted as high as possible. Their rotator cuff muscles, supraspinatus, infraspinatus, teres minor and subscapularis are used to finish the motion. It is encouraged to work the muscles that do the opposite action in order for movement to be effective. Muscles like the latissimus dorsi and lower trapezius can help in controlling this phase as well. With the shoulder rotated outward and above the throwers head, the UCL is at its most stretched here and at risk of tearing if the previously mentioned muscles are not being used.
The next phases are focused on accelerating the throwing arm forward. With the throwing arm rotated outwards as the muscles that rotate the shoulder inwards are now ready to be used, allowing the pitcher to go into the acceleration phase. In this phase the shoulder turns inwards, the throwing arm begins to speed forward into the next phase, ball release. The ball is released near the throwers head. The pitcher then straightens his arm and turns the shoulder inwards. In order to control this movement, strengthening the rotator cuff, latissimus dorsi and lower trapezius is important. These last two steps also put the UCL in trouble of tearing. If the previously mentioned muscles are not strong and working together, this puts a lot of stress on the UCL. In the final stage the ball is out of the pitchers hand yet other injuries to the their shoulder labrum, latissimus dorsi and rotator cuff can happen as well.
Muscles that are often forgotten in young pitchers are those that attach to the pelvis and lower trunk. This includes glute maximus, glute medius, hamstrings, quadriceps, adductors, obliques and quadratus lumborum. They help to accelerate the pitcher’s action of throwing because they are big and powerful muscles. However, young pitchers rely too much on their upper body to create acceleration, using smaller less powerful muscles in their arms and upper torso to do all the work.
While there are other issues related to UCL tears like high pitch counts and using off-speed pitches that stresses their young arms. Strengthening the muscles involved and those that do the opposite movements can create stability and decrease the chances of future UCL tears.