Latissimus dorsi—also known as lat—strains are becoming more common in Major League Baseball. In each of the past two seasons, Jacob deGrom and Steven Matz have been sidelined due to this injury, and unfortunately it is now Noah Syndergaard’s turn. While you can read my previous articles about this injury here and here, the focus of this piece is how to prevent such strains from happening.
Strains are very troublesome to deal with as there is little one can do until the muscle tissue has healed. Physical therapists and athletic trainers will use manual therapy to facilitate tissue healing and promote blood flow to the injured area. They will also prescribe exercises to other parts of the body in the meantime to make sure other muscles do not get weak until the athlete is ready to use the injured muscle again.
What are the lats and how do they play a role in pitching?
The lats are giant muscles that start in your low back and travel up to attach to your arm. Lats act, with other muscles, to extend, adduct (bring towards the body), and internally rotate (rotate towards the body) the shoulder. Given that the muscles start on the low back, they also contribute to core stability, protecting the spine during dynamic movements.
In pitching, the lats are responsible for not only the acceleration phase but also help during the deceleration phase. This means that the lats are responsible for how fast the ball is going to be thrown as well as controlling the arm during the follow through once the ball is released.
This can be problematic for power pitchers who are actively trying to pitch harder, as Syndergaard wanted to during this offseason. As pitchers attempt to creep up their arm speed and pitching velocity, more demand is placed on the lats; if they cannot keep up, the body is forced to compensate with other muscles to help accomplish the task. This is likely the reason why Syndergaard was originally diagnosed with biceps pain. Lat strains are already tough to diagnose as symptoms can be masked as more common injuries like biceps tendonitis, rotator cuff strain, etc. In addition, MRIs or arthrograms may not show the injury as the imaging may not cover the entirety of the injured area.
What is recovery like and how can lat strains be prevented?
A strain—a tear in a muscles—depending on severity, can take anywhere from 4-to-8 weeks to heal, assuming that surgery is not required for a full tear. The tricky part of treating a lat strain is that not only does the muscle need to regain its strength and size, but the muscle needs the endurance to last a full game to prevent a re-injury. It is for this reason that Syndergaard is shut down for 6 weeks to allow full recovery of the muscle before starting a throwing program that will likely take another six weeks to pitching in full form again (four-week tossing program, two weeks pitching off mound). According to a recent meta-analysis published last year, the average time of recovery for a lat tear in the MLB was approximately 100 days.
Unlike other muscles, the lats act in multiple planes of movement, meaning more demand is required of them than smaller and simpler muscles. As a result, not only will the lats recruit other muscles (biceps, rotator cuff, posterior deltoid, etc.) to help compensate, but the arm angle will change resulting in flawed mechanics that will lose the effectiveness of the pitch. Setbacks can occur relatively easily because of the demand and endurance required not only for one game but being able to recover in a span of 4-to-5 days in time for the next start.
This all leads to the major question of how can an injury like this be prevented. The key component of lat injury prevention is adequate shoulder flexion (moving your arm overhead), strength of the smaller muscles mentioned above, and core stability. Sub-optimal shoulder flexion means that the lat is tight and poor muscle length causes the muscle to strain if expected to perform at a consistently high level. Earlier I mentioned how if the lats are not strong enough, it will compensate with small stabilizing muscles. Vice versa, if these smaller muscles are weak, then the lats will be working overtime to complete the motion thus causing more overuse and “wear and tear”. Finally, poor core stability will throw off the entire motion of pitching as the force is transmitted from your lower body, through the core, to the upper body to throw the ball.
Overall, the pitcher needs to make sure not only that the lats are strong, but that all the muscles in the surrounding area are, as well. This will allow to the body to work cohesively to pitch effectively and efficiently. The pitcher also needs to make sure the lats are not tight and he has appropriate overhead mobility to decrease as much compensation from the other parts of the body.
A current fad in training with pitchers is using weighted balls to improve arm speed and pitching velocity. While in theory the use of weighted balls can increase performance, nothing replaces the importance of proper mechanics and technique that requires the main components of injury prevention (adequate alignment, mobility, stability, and control). The body will naturally break down throughout the course of a game and the season, but this can be combated with appropriate warm-ups, in-season training, and management. For even more info about lat strains, check out this awesome article by Eric Cressey, renowned strength coach for many current MLB players.