Strength in Numbers #199
Superior Labrum Anterior and Posterior (SLAP) tears are not exclusive to pitchers; position players, especially hitters, are also susceptible. The lead shoulder (left shoulder for right-handed batters) endures significant stress during the swing, making it vulnerable to such injuries.
While in professional baseball, one of my biggest worries was Shohei Ohtani. Impact risk to the throwing arm and hand was much less of a concern because of protective gear covering his lead arm, which is his pitching arm. Although his swing is so smooth, there’s a controlled violence to it, and the arm must decelerate to increase the speed of the barrel, and when you have a throwing arm that already takes a lot on, the risk of SLAP tears rises.
Most often, players hit the same side, so with a right-handed two-way player, like in high school, the throwing arm is not under the same amount of force when hitting. However, athletes who only perform the Quick Exam on our platform will miss the boat related to understanding asymmetries between sides and issues with the lead arm.
Please read this article series on the swing, and let’s talk about some things we need to put in place to protect all players, not just pitchers and two-way athletes.
Injury Stats and Mechanisms of SLAP Tears Happen in Swinging
During a baseball swing, the lead shoulder undergoes rapid internal rotation, horizontal adduction, and elbow extension, which generates substantial torques at these joints to increase barrel speed and maintain bat control. This motion stresses the superior labrum, particularly at the biceps tendon attachment point. Over time, repetitive swinging can lead to fraying or tearing of the labrum. When the rotator cuff is not optimized for strength, or the athlete has low scaption strength with an outstretched arm, the muscles’ ability to fire correctly to protect the shoulder region is compromised.
Additionally, training methods like underload and overload bat exercises that enhance bat speed can exacerbate the risk if the shoulder isn’t adequately conditioned. The unaccustomed loading, especially with an arm that is not well conditioned, can increase acceleration effects for the lead arm, translating to higher force potential. Weighted ball hitting is less frequent in hitting programming, but also increases the impact and jarring of the shoulder and elbow joint. There are no “right” or “wrong” training methods, but the risk rises if the shoulder and elbow strength metrics are off, such as decreased grip strength or shoulder scaption.
The hitting sequence involves picking up pre-pitch cues in the stance. The hitter then initiates the swing and stores energy with a negative move. From the furthest point in the load, the hitter makes a positive move forward and lengthens the stride toward the pitcher. The swing is launched at the weight-bearing foot plant, and the bat picks up acceleration as the lead arm slows down. The bat then collides with the ball to smash the ball against the bat, and the bat bends slightly to catapult the ball off the barrel. After contact, the athlete decelerates the swing until it’s dropped to the ground on a hit.
Current Research Insights
A study analyzing 3,414 shoulder injuries in professional baseball batters found that SLAP tears had the highest season-ending rate (35.3%) and a significant need for surgical intervention (45.1%). This underscores the severity of SLAP injuries in hitters (Ref)
I am seeing this percentage rise in amateurs, as I have a good number of athletes who have had lead arm injuries that impact the shoulder region. Some have had their swing completely altered after surgery. In the process, reduced horizontal adduction of the lead arm (arm coming across the body to load and keep the lead shoulder closed) impacts hitting performance.
Further research indicates that poor lumbopelvic control and hip weakness are associated with increased shoulder and elbow stress in pitchers. While this study focuses on pitchers, the findings are relevant to hitters, emphasizing the importance of core and hip strength in preventing upper extremity injuries, as a lack of stabilization through launch increases energy flows to be absorbed by the shoulder. Energy leaks can impact bat speed, but overcharging the lead arm may be problematic.
This is a good speed drill for hitters and pitchers. We teach this start drill in our onsite educational courses, as any reduction in sprint speed, jump ability, and throwing arm strength (RJT Factors as I call them) significantly raises the risk of injury. It is always important to train both sides of the body, but note the direction of force involved.
Injury Prevention Strategies
- Strength and Conditioning: Focus on strengthening the rotator cuff and scapular stabilizers to support shoulder integrity.
This exercise is focused on co-contraction, trunk stabilization, and outstretched arm deceleration. Do not waste energy with the positive phase by making the band too heavy, as the emphasis needs to be on the deceleration phase, which is focused on handling rapid lengthening or traction.
- Proper Mechanics: Ensure correct swing mechanics to distribute forces evenly and reduce undue stress on the shoulder.
Early arm bar, essentially lock out the elbow early in the launch phase, could increase load on the biceps and shoulder, but could also sacrifice swinging velocity, so careful review is needed there, and the rules apply to hitting – take a Strength & Coordination Approach. First, fix strength and tissue length, and then address mechanical factors.
- Gradual Progression: Progressively introduce underload and overload bat training, allowing the shoulder to adapt to increased demands. Athletes do need to understand how to scale intensity. Never let them swing without an intensity rating, and they should be monitored for technique and appropriate effort. Single numbers like 5/10 for effort on swings are much easier than a range, such as 4-5/10 effort. Don’t ever confuse the athlete, whether it is in rehab or regular programming.
- Regular Assessments: Conduct periodic evaluations of shoulder function and strength to detect early signs of overuse or imbalance.
This is where the rubber meets the road. If you throw and hit on opposite sides, you can get away with a Quick Exam, but even then some, diving injuries occur, or sliding injuries (think Shohei Ohtani in the World Series), so it is best to test both arms with a Full Exam at least once per month and adjust programming.
You must also understand where asymmetries lie and how far away the glove arm is from the throwing arm. If you have a weaker throwing arm, comparatively, your fatigue level needs to be in check. We have a central nervous system fatigue issue if both arms lose strength.
This is what we want to see and keep building toward. Note that total arm strength increases for the athlete, and the difference in strength between sides decreases, meaning the nervous system functions well. The athlete in this case has high scaption strength, which is essential, and is completely balanced in the test, while grip is quite close. We want the arm to be equal to or stronger than the non-throwing arm, but a good asymmetry range should be less than 10%.
Rehabilitation and Return-to-Play Timeline
Non-Surgical Approach:
- Rest and Physical Therapy: Initial treatment involves rest and a structured physical therapy program focusing on restoring range of motion and strengthening the shoulder muscles. You need to test and should not pick up a bat until your strength values are optimized. Essentially, the lead arm should have improved strength through this process, and an ArmScore over 100 provides even more protection.
Note the PR value of 100 for the ArmScore. This athlete must be beyond that level, and likely more toward 110 based on the body size and the force that could be produced. There’s work to do, but that’s why we evaluate continually. We all want faster return to competition times, but our athletes must have greater capacity than previous injury states and have consistent neurological activation for force production.
- Swing Progression: Once symptoms subside, a gradual return to swinging is initiated, emphasizing proper mechanics. Again, the swings would be light, and I would not include a baseball for a little while to prevent the athlete from focusing on damage or being encouraged to pick up the pace, as they will not have weaker contact. Be as detailed as possible. At the pro and college level, athletes have access to ball flight tracking equipment and radar technology, but portable bat sensors can provide feedback on how hard to swing, when to back off, and when to rest the lead arm.
Surgical Intervention:
Surgical Intervention:
- Post-Surgery Rehabilitation: The shoulder is immobilized in a sling for approximately six weeks following surgery.
- Physical Therapy: Rehabilitation focuses on restoring range of motion, followed by resistance training and plyometric exercises. Please refer to the section above. A data-led approach to your rehabilitation is essential and, in my opinion, non-negotiable. Just because you go through physical therapy does not mean that imbalances, weakness, recoverability, and overall strength have been corrected.
- Return to Hitting: A hitting program typically begins around four months post-surgery, starting with air swings and progressing to live batting practice. When ball flight is a component, such as front toss, try to avoid the extension side or outer part of the plate until you denote high recoverability and low fatigue. Like anything, your return-beyond-performance plan must alternate between days challenging the lead arm and days underloading. Full return to competition is generally expected between five and six months postoperatively.
- Biomechanical Assessment: If swing components along the hitting discrete events and phases are not improved, you risk a secondary injury or further complications. Identify places that perform a biomechanical review of your swing and select drills that will help correct inefficiencies. Please note, do not enter this phase until you hit at 100% effort, pain-free.
It should be intuitive that the next day’s hitting progression should be reduced based on the fatigue level of the lead arm. If this is early in the progression, like this athlete above, take a day off the next day and repeat the progression in the following to examine if fatigue is maintained, or if the nervous system was optimized.
Takeaway Message
SLAP tears in the lead shoulder are a significant concern for baseball hitters. Understanding the mechanisms of injury, implementing preventive strategies, and adhering to a structured rehabilitation program are crucial for recovery and return to play. Back your hitting progression with regular assessments using the ArmCare.com platform to help mitigate the risk of re-injury and ensure long-term shoulder health.