Why Hip Mobility is Important in Baseball Pitchers – Part 2

The pitching delivery requires the entire kinetic chain to work as one unit in order to be successful. While the throwing shoulder continues to get a lot of attention in the baseball community, and rightfully so, isolating the shoulder paints an incomplete picture of what occurs while hurling a baseball. The hip is another joint worth taking a look at when examining the baseball pitcher. In a previous blog, we discussed the importance of hip internal rotation during the early parts of the stride phase as it pertains to generating power through the hips and pelvis (click here). This blog served to explain the importance of drive leg hip internal rotation but fell short of explaining the importance of hip internal rotation in the contralateral hip during the later stages of the stride phase. In this blog, I hope to address that.


As a pitcher progresses through the stride phase, their lead leg eventually touches down on the pitching mound as they transition to the cocking phase. The location of foot contact can have major implications on the subsequent phases of the pitching delivery. Stride width refers to the distance between the two foot positions in the horizontal plane (3). This term is essentially used to identify whether a pitcher is landing closer to first or third base. A right-handed pitcher landing closer to third base would represent a positive stride width, or ‘closed’ landing position. A right-handed pitcher landing closer to first base would represent a negative stride width, or ‘open’ landing position.

Landing in a Closed Position


In a study conducted by Manzi and colleagues, it was shown that professional baseball pitchers who land in an excessively closed position tend to have less pelvic rotation at front foot contact (3). This means that the pelvis is rotated more towards third base, for a right-handed pitcher, than it is towards home plate when the front foot lands. In addition to landing with a more negatively rotated pelvis, which in and of itself is not a bad thing, the lead hip is also landing in a position of relative internal rotation in these individuals. This is important, as landing in a position of relative hip internal rotation has the potential to limit subsequent rotational capabilities at the hip and pelvis. With this in mind, it may not come as a surprise that the same study concluded that pitchers who land in a closed position have significantly less pelvic rotation at ball release when compared to those who land in a more narrow position (3). A lack of pelvic rotation during the pitching delivery may have several implications, one of which being a decreased ability to generate power from the lower half.


It has been shown that pitchers who land in a closed position have less hip shoulder separation than pitchers landing in an open position (4). This would make sense as, after all, pelvis rotation is one of the variables used to calculate this metric, and closed pitchers tend to have less of it. In a previous blog, we discussed the importance of achieving hip shoulder separation as it pertains to pitch efficiency and velocity (click here). In short, pitchers who are able to achieve hip shoulder separation are also able to generate higher rotational velocities at the pelvis and trunk. Increased rotational velocities at the pelvis and trunk allow the pitcher to generate power proximally before transferring it more distally to the throwing arm. Not only does this help to increase fastball velocities but it may also serves as a protective mechanism to limit the amount of the stress placed on the throwing shoulder and elbow. A decrease in hip shoulder separation, however, limits the ability to efficiently transfer energy to the throwing arm.



In order to compensate for this disruption in timing, the throwing arm must speed up after losing momentum in order to get to the appropriate ball release point. This results in a late whipping action that increases shoulder ranges of motion and places additional stress on the anterior shoulder, scapular stabilizers, and medial elbow (1). In order to improve their timing, these types of pitchers tend to flex their trunk earlier in the delivery and tend to throw from a lower arm slot (3). This historically has been referred to as the “crossfire” approach, or throwing across the body. These adjustments give the pitcher a better chance at improving their ball release point. If a pitcher is unable to make these adjustments late in the delivery, it will likely be extremely difficult to throw a glove side fastball, with the pitcher having a tendency to run a fastball up and away.


These considerations don’t mean that we should automatically vilify this pitching delivery. As Matt Hinkley, Pitching Coordinator at Cressey Sports Performance, said, “If someone has the thoracic rotation and athleticism to execute the crossfire approach, leave it alone.” That is because this type of delivery requires the pitcher to get the range of motion from somewhere besides the hip and pelvis and have the athleticism to repeat this difficult movement time and time again (it also probably wouldn’t hurt to have exceptional lead hip internal rotation, as that would allow the pitcher to better utilize the pelvis). Chris Sale is one of the best of all time at doing this. He has the ability to effectively throw across his body, adding a component of deception to his delivery and a ridiculous amount of horizontal movement to his pitches. Trying to overhaul a pitcher with a track record of success like Chris Sale may be a quick way to find yourself searching through job boards. While you may not see pitching coaches teaching this delivery to the youth, it has led to multi-million-dollar contracts, Cy Young awards, and Hall of Fame careers for some.


Landing in an Open Position


Landing in a position that is excessively open creates a similar but different set of problems. Contrary to landing in an excessively closed position, landing open has been shown to result in higher pelvic rotation values at front foot contact (2,4). This means that the pelvis is rotated more towards home plate as the stride leg makes contact with the pitching mound. The premature rotation of the pelvis can throw off the timing of the pitching delivery, resulting in the trunk rotating early as well. Once again, this leads to a decrease in hip shoulder separation. As potential energy is lost due to poor timing of the pelvis and trunk, the upper extremity is asked to make a valiant effort to compensate for the deficiency. Similar to landing in an excessively closed position, the throwing arm lagging behind the body places additional stress on the anterior shoulder and medial elbow (1,2).



In order to give the pitcher a better chance at hitting the strike zone, a second compensation is also present during this style of delivery, this time at the forearm. Pitchers who land in an excessively open position tend to supinate their forearm more as they approach ball release (4). This increase in supination helps to keep the ball facing home plate despite the entire body being open at the later stages of the delivery. Excessively supinating the forearm may increase the likelihood of a fastball running up and away due to the pitcher having a tougher time staying on top of the ball. Not only does this style of delivery make it difficult to cut a fastball but it may also result in the propensity to hang breaking balls.


One possible reason for a pitcher landing in an excessively open position may be poor hip internal rotation of the stride leg. While discussing the implications of landing in a closed position, we mentioned how landing in this position puts the lead hip in a position of relative internal rotation at front foot contact. Landing in an excessively open position does the opposite. Pitchers landing in an open position have a tendency to rotate their pelvis prior to front foot contact. This early rotation of the pelvis effectively opens up the lead hip into a neutral or externally rotated position. It may be that a pitcher simply doesn’t have the real estate in that lead hip to achieve a proper landing position so they compensate by opening up early. For this reason, it is important to assess hip mobility of not only the drive leg but also the stride leg. Without adequate hip internal rotation mobility, it will be difficult to coach a pitcher into a more neutral stride width.


The “Ideal” Stride Width


So, do we want our pitchers to land in a closed or open position? Well, like most things, the answer may lie somewhere in the middle. It has been shown that landing in a slightly closed position may be the most advantageous for utilizing the kinetic chain (3). Landing in a slightly closed position allows the pitcher to begin rotating their pelvis after front foot contact without restricting the pelvis’s ability to do so, as is seen with an excessively closed position. This in turn allows the pitcher to delay trunk rotation and achieve better hip shoulder separation. Achieving these positions may allow the pitcher to achieve higher rotational velocities at both the pelvis and trunk, allowing for more energy to be transferred to the more distal segments of the throwing arm. As we mentioned earlier, this not only helps to improve throwing velocity but may also help to limit the amount of stress placed on the throwing arm. In fact, it has been shown that pitchers who are able to delay trunk rotation experience lower elbow varus torque as well as reduced shoulder internal rotation torque (3).



We discussed, though, that a pitcher with limited lead hip internal rotation may have a difficult time achieving a slightly closed landing position. One possible adjustment a pitcher with limited hip internal rotation can make is to change their foot position on the pitching rubber. For example, a right-handed pitcher could move to the first base side of the pitching rubber. This starting position allows the pitcher to stride directly towards home plate, which would still result in a slightly closed stride width, but reduces the amount of pelvic and trunk rotation necessary to throw to their glove side. In this case, adjusting the starting position may give the pitcher a better opportunity to get their arm out in front of their body during ball release, improving their ability to snap off a breaking ball or cut a fastball.


Summary


Stride width refers to the contact position of the lead leg during the end of the stride phase of the pitching delivery. A right-handed pitcher landing closer to third base would represent a positive stride width, or ‘closed’ landing position. A right-handed pitcher landing closer to first base would represent a negative stride width, or ‘open’ landing position. Like most things, being on the extreme end of this spectrum may come with its own set of challenges. If a pitcher lands too closed, they may have a decreased ability to rotate their pelvis towards home plate. If a pitcher lands too open, they may rotate their pelvis too early, leading to them rotating their trunk too early and their arm lagging behind. While these two landing positions may lead to different alterations in the kinetic sequence, they both lead to a decrease in hip shoulder separation, which has the potential to decrease throwing velocity and place additional stress on the throwing arm.


Now it’s important to note that there is no one size fits all approach to throwing a baseball. Sometimes the same thing that makes a baseball pitcher different is also what makes them successful. Chris Sale is a great example of this. You won’t find many coaches teaching his mechanics to the masses but hitters have a hard time hitting him because of the deception that his delivery provides.


The point I hope to have made while writing this blog is that there is more to the pitching delivery than just shoulder range of motion and rotator cuff strength. It is our duty to examine the entire kinetic chain so we are better able to optimize performance while simultaneously mitigating the risk of injury in our baseball pitchers.



References


1. Calabrese GJ. Pitching mechanics, revisited. Int J Sports Phys Ther. 2013 Oct;8(5):652-60.

2. Fortenbaugh D, Fleisig GS, Andrews JR. Baseball pitching biomechanics in relation to injury risk and performance. Sports Health. 2009 Jul;1(4):314-20.

3. Manzi JE, Brusalis CM, Dowling B, Krichevsky S, Quan T, Huang D, Moran J, Kunze KN, Dines JS. The influence of stride width on kinematic and kinetics in high school and professional baseball pitchers: A propensity-matched biomechanical evaluation. J Sci Med Sport. 2022 Jul;25(7):599-605.

4. Slowik JS, Diffendaffer AZ, Crotin RL, Stewart MS, Hart K, Fleisig GS. Biomechanical effects of foot placement during pitching. Sports Biomech. 2021 Apr 6:1-10.