Written by: Joe Rauch and Paul Buchheit — Philadelphia Phillies
As elbow injuries in baseball continue to rise, the conversation on how to keep these athletes healthy is constantly evolving. Delivering a baseball pitch is one of the most dynamic and violent actions in all of sports. The mechanical stresses that the body must absorb are incredible and without adequate acceptance can lead to decreased performance or possible injury. Each repetition is a synchrony of strength, timing and force production to deliver a perfectly executed pitch.
Image courtesy of pjstar.com (https://www.pjstar.com/story/sports/mlb/2017/02/14/cardinals-pitcher-alex-reyes-has/22463633007/)
Specifically, the most commonly discussed injury in baseball is the UCL sprain in the elbow of pitchers. Stress is transferred from the ground up through the body to a focal point in the elbow. There are traction and valgus forces through the elbow during the acceleration phase of pitching that specifically stresses the UCL ligament. The inability to accept that stress as well as transfer it efficiently will create changes over time and repetition. In some cases, this can lead to injury.
The elbow uses two methods to withstand the forces produced in the pitching motion. Static and dynamic stability.
- Static stability consists of the anatomical joint structure. This includes the bony joints of the elbow as well as the soft tissue that connects them.
- Dynamic elbow stabilization involves that same tissue, but considers how well they function in harmony with each other.
The traction and valgus force in the elbow during a pitch creates a potential opening or gapping of the inside of the elbow joint (1). The ability to stay healthy long term can, in part, be attributed to how well that space is maintained and controlled during pitching activity.
Much of the conversation surrounding keeping pitchers healthy is how we can not only train the dynamic stabilizers, but how do we measure how well they are prepared and able to function and do their job. Literature shows that squeezing the hand and causing a contraction of the flexor pronator muscle group can affect the space in the medial joint when stress in placed on it (2). So, in theory, the better that tissue is at contracting correctly, the better it will be able to take on the extreme forces of baseball pitching. Thus, limiting the traction forces and strain on the UCL ligament (3).
Measuring and monitoring grip strength is seen throughout baseball in various applications. It was viewed as a way to measure the local tissue directly involved in dynamic elbow stability and could be a predictor of poor function and therefore a potential risk to handle high level stresses. In 2024 Erickson et al showed that in fact, there was no correlation between changing grip strength measures and injury in professional baseball players in one organization (4). This goes against conventional thinking that grip strength can help predict injury risk.
But if grip strength is not related to injury, why do measurements vary so drastically for each player throughout the season? Standard deviations of 20-30 pounds were not uncommon in this population (Figure 1). These measurements are telling us something. While it may not be directly related to local joint health, maybe there is a fatigue monitoring component. Erickson and his group again attempted to better define this answer with a study in 2024 where grip and pincer strength measurements were taken between innings for pitchers in one professional baseball team (5). In this study, there were signs of fatigue when taking serial measurements. Force production decreased each inning for the first four innings and despite a slight increased after the fifth inning, the total force never returned to pregame levels. Maybe grip strength is not the strength and function indicator we were hoping it was. However, it might be the quick, easy and cost-efficient way to monitor overall neurological fatigue that can impact decision making.
Figure 1
In a sports medicine world that continues to grow with the amount of information available as well as varying definitions of what constitutes “workload”, being able to decipher the information into what matters most presents a developing challenge for the high-level athlete. The decision making of when to push therapeutic and corrective exercise as well as communicating with our strength and conditioning colleagues on appropriate load modifications can be a crucial piece in preventing injury. A poor grip strength force production on one specific rep, at one specific moment in time may not demonstrate that the player is weak. Instead, it may more specifically indicate that they are neurologically fatigued. The decision to offer recovery treatments to stimulate the likelihood of availability and improved performance the next day can help limit unnecessary exercise repetitions on already fatigued tissue. Conversely, it can also help decide when an appropriate time to push those necessary exercise activity in moments when on-field play may be going through a particularly efficient time period.
Currently evidence remains limited. Athletic trainers remain committed to working towards creative ways to help curtail the rise in baseball elbow injuries. Tracking grip strength more robustly through the season and adding it to a comprehensive decision making arsenal can help make more granular and appropriate exercise prescription decisions. This can maximize player availability and improve performance over the course of the season.
For more information on grip strength research and implementing a plan with your team check out the Inside Athletic Training podcast episode #74 featuring Phillies Head Athletic Trainer Paul Buchheit and Assistant Athletic Trainer Joe Rauch here!
REFERENCES
- Ciccotti MG, Atanda A Jr, Nazarian LN, Dodson CC, Holmes L, Cohen SB. Stress sonography of the ulnar collateral ligament of the elbow in professional baseball pitchers: a 10-year study. Am J Sports Med. 2014 Mar;42(3):544-51. doi: 10.1177/0363546513516592. Epub 2014 Jan 28. PMID: 24473498; PMCID: PMC4131844.
- Pexa BS, Ryan ED, Myers JB. Medial Elbow Joint Space Increases With Valgus Stress and Decreases When Cued to Perform A Maximal Grip Contraction. Am J Sports Med. 2018 Apr;46(5):1114-1119. doi: 10.1177/0363546518755149. Epub 2018 Mar 7. PMID: 29513547.
- Noda I, Kudo S. Relationship between pain, elbow valgus instability, and the function of flexor pronator muscles in baseball players. JSES Int. 2020 Oct 31;5(1):31-34. doi: 10.1016/j.jseint.2020.09.007. PMID: 33554160; PMCID: PMC7846683.
- Erickson BJ, Buchheit P, Rauch J, Ciccotti MG, Paul RW, Cohen SB. Is There a Relationship Between Grip Strength and Injuries in Professional Baseball Players? Orthop J Sports Med. 2024 Jul 31;12(7):23259671241257622. doi: 10.1177/23259671241257622. PMID: 39100217; PMCID: PMC11295228.
- Erickson BJ, Buchheit P, Rauch J, Ciccotti MG, Paul R, Cohen SB. Change in Grip and Pinch Strength Over the Course of a Game in Professional Baseball Pitchers. Sports Health. 2024 Dec 23:19417381241305401. doi: 10.1177/19417381241305401. Epub ahead of print. PMID: 39711178; PMCID: PMC11664553.