Today’s guest post comes from Kristin Tognetti PT, DPT, MTC. Kristin graduated from the University of St. Augustine for Health Sciences in 2008 with a Doctorate in Physical Therapy, and later received her Manual Therapy Certification from the same institution. She currently works for Spectrum Rehabilitation in Colorado Springs, CO. You can learn more about Spectrum Rehab by visiting them online at www.spectrumrehab.net.
I recently went to the APTA’s Combined Sections Meeting in New Orleans, LA. One of the topics I found interesting was shoulder injuries in baseball pitchers. The following article will detail some of the information I learned.
Many baseball players are familiar with the terms “Tommy John Surgery” or “Thrower’s Shoulder” and even “SLAP tears.” This is because many baseball pitchers will sustain a shoulder or elbow injury throughout their careers. There have been several studies performed by well-renowned physicians and physical therapists looking at every aspect of the biomechanics of each pitch that show the amount of force placed through the elbow and shoulder. Common knowledge suggests that curveballs and sliders place the most stress on the elbow and shoulder, and it is therefore discouraged for any youth (any pitcher that has not reached skeletal maturity) to learn how to throw and/or use these pitches during practices and games to help prevent injury. But did you know that the amount of hip mobility (specifically hip internal and external rotation) and core strength also play a key role in the prevention of shoulder and elbow injuries?
In a study by Robb, Fleisig, Wilk and Macrina (AJSM 2010), they show that trunk separation and hip range-of-motion are directly correlated to the velocity of a pitch. The greater the total amount of the dominant and non-dominant total abduction and adduction (stride length), as well as total arc motion of hip internal and external rotation, can decrease stress on the shoulder and elbow while increasing the velocity of the ball. Wilk (CSM 2011) also explained that the lead foot contact should be placed in a slight amount of internal rotation to decrease stresses on the medial elbow and shoulder. If a pitcher has a completely open foot upon landing with his stride leg, the stress on the anterior shoulder can be increased by 15-20% during the arm cocking phase of a pitch.
Of course, in order to have a strong pitch, one must also have strong legs and core strength. During the biomechanics of a pitch, the potential energy is transferred from the hips and the core, to the throwing arm, and finally to the ball. In conclusion, it is important for the baseball pitcher to not only have adequate (or excessive) shoulder range of motion and upper extremity strength, but it is also crucial to obtain proper hip range of motion in abduction, adduction, internal and external rotation, and hip and core strength all while using proper throwing mechanics and correct foot placement to increase ball velocity and decrease chance of injury to the shoulder and elbow.