Earlier this week, I found myself in another interesting conversation regarding UCL tears. For those of you who do not know, UCL tears and their prevention has been a passion project for me over the past 2 – 3 years. Having gone through north of 250 research articles regarding the ligament, I believe I have run through just about every publication imaginable to date regarding baseball and UCL tears.
To take a quick step back, the UCL is the abbreviation for an elbow ligament known as the Ulnar Collateral Ligament, which runs from the funny bone to a long part of the ulna. In more “science-y” terms, the UCL is actually comprised of three ligaments:
1) the anterior bundle, which originates on the humerus slightly distal and lateral to the medial epicondyle and inserts on the ulna just distal to the joint line on the sublime tubercle, with its footprint extending distally along the ulnar ridge.
2) the posterior bundle – which originates on the humerus and attaches slightly distal and lateral to the medial epicondyle and posterior to the anterior bundle and inserts into the oblique bundle of the UCL, posterior to the joint line.
3) the oblique bundle – of which both attachments are located on the ulna, the anterior attachment closer to the ulnar ridge, and the posterior attachment between the joint line and the olecranon (1).
With its unique attachment on the medial side of the arm, the UCL and specifically the anterior bundle, is the ligament of greatest concern to baseball players. The reason: the main function of the anterior bundle of the UCL is to prevent the forearm from flying off of the body while the arm accelerates forward in a throwing motion. Consequently, the UCL is subject to extreme torques in the throwing motion.
The torque or twisting force that throwing places on the elbow is considered a valgus load. Valgus load testing has shown that the UCL will tear with roughly 35 newton meters of torque cadaveric studies. Newton meters are simply a measurement of how much torque is being applied to an object under stress, in this case the elbow when throwing a baseball. The really interesting piece in this whole equation is that torques on the elbow while throwing a baseball 80+ mph have been calculated between roughly 80nm (2) and 115nm (3). So if load testing shows that the UCL alone tears at roughly 35 newton meters, it does not take an advanced calculus degree or rocket science to figure out that the UCL should technically tear on every throw that is made above a certain torque level. The only reason it doesn’t is the muscles of the flexor pronator mass – specifically the flexor carpi ulnaris (FCU), flexor digitorum superficialis (FDS), and flexor digitorum profundus (FDP) (4)– and the radiocapitellar joint play a huge role in off-loading stress from the UCL.
Now, it is rare that I go a week without reading at least one blog or listening to a podcast that discusses different grip exercises or throwing mechanics offering a familiar refrain, “with perfect mechanics and a strong build there is no way a pitcher can tear his UCL.” While no doubt well-intentioned, according to 25 years of research, this statement is both misguided and misleading.
First, in regards to mechanics, a ligament does not care about how you throw. The only thing that matters to a ligament is stress. With the UCL, that stress is torque. The common response to this statement is that torque will go down with improved mechanics. However, the number one indicator of elbow torque is velocity. As velocity continues to increase so does torque. Don’t get me wrong, I think clean mechanics are absolutely essential for velocity gains and the longevity of a pitcher, but in synthesizing the findings of over 250 articles over the last 2-3 years, it is clear that throwing mechanics have at best a minimal impact on UCL health.
Second, in regards to strength training, if the right exercises were available, wouldn’t you think this whole UCL tear thing would be a complete anomaly? But, the fact that over 30% of all pitchers to throw a pitch in the MLB in 2019 had undergone Tommy John surgery at some point in their professional career (5) makes it obvious that current strength training approaches cannot solve the problem.
Whenever I hear a misguided and/or uninformed coach say, “he tore his UCL because he is an awful mover,” or “he wasn’t strong enough to pitch that hard,” I am stuck having to straight-face these conversations, only to become a keyboard warrior and preach to those willing to listen.
These exact reasons are actually why I have done a complete 180 on the weighted ball debate. In my own coaching, I will not prescribe weighted ball training/throwing to every kid; however, after checking a few boxes, I have no issues with their implementation. Again, the UCL doesn’t care whether a ball, a rock, or a dumbbell is being thrown. It is a ligament. The implement doesn’t matter. All that matters is the torque, and if the unit itself can withstand the torque of throwing, you are in the clear.
I understand that UCL care is not that simple. I poked holes, but didn’t offer solutions. I will do my best to cover my tracks in an easy to understand, yet in depth summary.
As stated already a few times, all that matters is torque. That being said, exceeding the acceptable torque limit on the elbow just one time does not necessarily mean it will blow out. In most instances, when the torque generated by pitchers exceeds the limit of the UCL, the UCL does not suffer a complete blow out. Rather, small microscopic tears occur. Do this enough and then the full blow out occurs.
This is why workload management is huge in injury prevention. The body, and especially the elbow unit, must be given time to adapt to the stresses it must endure in throwing. Whether it is a slow, progressive ramp up, or a steady throwing schedule during the season, throwing too little can be just as harmful as throwing too much. By throwing too little, max effort or extended throwing days become more dangerous as the elbow unit is not used to the high levels of stress associated with high intensity throwing. On the other side, never giving the arm and body a chance to recover would be like max bench pressing 4 days in the same week. There is just no way the body can perform something that intense, that often. This is why a throwing schedule with progressive loading, even in season, is essential to account for the ebbs and flows of a season and for injury risk management.
When it comes to training, the flexor pronator mass is really the only thing that matters in UCL injury risk reduction. Coaches, trainers, and physicians can talk about strength, mobility, power, and flexibility of every other part of the body until the cows come home. While these can most certainly impact velocity and overall health, they have little to do with protecting the UCL. Before you dismiss this assertion, just ask yourself, do you honestly think Noah Syndergaard, Jacob DeGrom, Shohei Ohtani and the 1200+ other MLB players who have torn their UCL over the past 10 years lacked power and mobility. Of course they didn’t! Only three muscles have been found to provide any meaningful support to the UCL – FCU, FDS, and FDP. As touched on earlier, there is currently no perfect training program or exercise series on the market. That is a gap I am trying to fill with my company, FlexPro Grip, in the very near future. In the meantime, while they will not completely solve the problem, what I best suggest are plate holds, wrist adductions, and anything involving individual finger flexion. Plate holds and finger flexions target the FDS and FDP, while wrist adduction targets the FCU. For overall health, it is also important to add some forearm exercises such as wrist rollers and forearm curls to achieve some balance in both flexor and extensor muscles.
In review, this was a funky article for me to write as I attempted to take an extremely scientific concept and bring it to the masses. However, to spread the word properly, that is what needs to be done. The most important points to walk away with here are as follows:
1) Excessive torque is what tears the UCL - not mechanics, strength, or arm slot. Those things can play factors in the torque on the UCL, but the UCL tears when it can no longer handle the torque placed on the elbow by throwing.
2) Increased velocity is the number one indicator of increased torque on the elbow for an individual (6). If one person throws 90mph and another throws 85mph, it does not necessarily mean that the 90 guy places more torque on his elbow. But, if both increased by 2mph, both would increase their torque levels.
3) Only three muscles play any significant role in offloading stress from the UCL – the FDS, FDP and FCU.
4) The UCL does not care about the implement being thrown. Torque is all that matters.
5) Management is huge. Track throws, intent of throws, and velocity, if possible.
If you have questions regarding UCL health or studies to look at, feel free to reach out. I would be happy to help.
Adam Moreau, MBA, CSCS
Director of Player Development and Recruiting Coordinator
Eckerd College
419-250-7243
Citations
1.Understanding the MUCL of the elbow: Review of native ligament anatomy and function Joshua R Labott, William R Aibinder, Joshua S Dines, Christopher L Camp. World J Orthop 2018 June 18; 9(6): 78-84.
2. Kinetic Comparison Among the Fastball, Curveball, Change-up, and Slider in Collegiate Baseball Pitchers. Glenn S. Fleisig, PhD, David S. Kingsley, Jeremy W. Loftice, Kenneth P. Dinnen, MS, Rajiv Ranganathan, Shouchen Dun, MS, Rafael F. Escamilla, PhD, and James R. Andrews, MD. From the American Sports Medicine Institute, Birmingham, Alabama. 2006.
3. Computing Muscle, Ligament, and Osseous Contributions to the Elbow Varus Moment During Baseball Pitching. Buffi, J.H., Werner, K., Kepple, T. et al. Ann Biomed Eng 43, 404–415 (2015).
4. Ulnar Collateral Ligament Injuries in the Throwing Athlete. Jeremy R. Bruce, MD James R. Andrews, MD. 2014.
5. Tommy John Surgery List. @MLBPlayerAnalysis. https://docs.google.com/spreadsheets/d/1gQujXQQGOVNaiuwSN680Hq-FDVsCwvN-3AazykOBON0/edit#gid=0
6. Fastball Velocity and Elbow-Varus Torque in Professional Baseball Pitchers. Jonathan S. Slowik, PhD; Kyle T. Aune, MPH; Alek Z. Diffendaffer, MS; E. Lyle Cain, MD; Jeffrey R. Dugas, MD; Glenn S. Fleisig, PhD. J Athl Train (2019) 54 (3): 296–301.
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