Strength in Numbers #212
I was in my early teens when the Steroid Era in baseball arrived. Before that time, commonly held beliefs considered training for muscle size to be a career-ending approach, particularly increasing the size of the biceps, as the consensus believed the muscle to be counterproductive to throwing efficiently or effectively.
The scientist in me now would have first gone to Google Scholar to find any bit of peer-reviewed research to support this claim. I didn’t believe the hype, as you could see players like Raul Mondesi, Jose Canseco, and Ken Caminiti throw the baseball 95mph+ on the field and had arms the size of my legs.
Players during the Steroid Era were imposing – humongous players that looked like they could wrestle in WWE, but the players in the modern era, without the use of performance-enhancing drugs, are much larger relative to their body height, meaning that overall, the modern-day baseball player is more physical.
Still, when it comes to throwing athletes, the conversation typically revolves around rotator cuff function, scapular control, or even forearm mechanics. But one muscle group that often gets overlooked—yet plays a critical dual role in performance and protection—is the biceps brachii.
For throwing athletes, the biceps aren’t just about arm curls and aesthetics. It’s a shock absorber, a braking system, and a stabilizer. I believe training my biceps saved my career, and I owe it to the book written by Jose Canseco and Dave McKay – Strength Training for Baseball. At 13 years old, I could bench press my body weight 10 times, and with integrating curls 3x per week, my elbow, which once had an extreme growth plate injury, never, ever bothered me again.
This article breaks down how this muscle influences shoulder and elbow health, how it can go wrong, and what to do to keep it strong and resilient.
The Biceps: A Dual-Joint Stabilizer
The biceps brachii crosses both the shoulder and the elbow, making it a biarticular muscle. It has two heads:
- Long head: Originates from the superior glenoid labrum, running through the bicipital groove.
- Short head: Originates from the coracoid process.
Both heads insert on the radial tuberosity, assisting in elbow flexion, forearm supination, and shoulder stabilization, especially in overhead motions.
As you can see, the biceps muscle is a fascinating muscle, one of the very few upper body muscles that cross two joints – that means it has prime moving capabilities, it is a decelerator, but also a stabilizer, especially at the point of ball release, when all hands on deck work to keep the humeral head (ball of the shoulder head) in its socket.
During a throw, the biceps have some major roles for throwing arm health and performance:
- Decelerate the elbow extension post-ball release.
- Helps resist anterior shoulder translation – meaning the arm sliding forward
- Assists in controlling valgus stress at the elbow in tandem with the flexor-pronator mass, meaning it helps resist loading that exposes athletes to TJ surgery.
Mechanisms of Biceps Injuries in Throwers
- Long Head Biceps Tendinopathy
The long head gets compressed between the humeral head and the acromion in the late cocking phase of the throw. Overuse causes:- Microtears
- Inflammation of the tendon sheath
- Labral strain, where the tendon anchors
This is from our Certified Pitching Biomechanist Course – the biceps have to contract to stabilize the elbow near maximum layback. Still, they then must aggressively contract while lengthening to slow down elbow extension at ball release. These two time points – maximum layback and ball release have high loads on the biceps tendon. If the biceps cannot dissipate force well, then the tendon may put too much tension on the labrum of the shoulder, which may result in a SLAP tear.
- Distal Biceps Tendinitis
Common in throwers who overload elbow flexion or have poor deceleration control. Tight grip or repetitive throwing without adequate forearm strength can aggravate the distal tendon.
Biceps carry is a good way to integrate the core, the shoulder joint, and the biceps to improve trunk, shoulder, and elbow deceleration. In this exercise practical from our Certified ArmCare Specialist Course, you can see how negatives are integrated into the carry variation.
- Biceps Rupture or Subluxation
When the long head slips out of the bicipital groove due to biceps pulley injury (subscapularis or supraspinatus weakness), it may rupture or irritate the labrum.
Coaches need to monitor athletes’ shoulder balance to ensure the humeral head, the end point of the upper arm bone, is centered on the glenoid and labrum, which is the cup end of the shoulder socket. They don’t exactly fit perfectly together, so the muscles surrounding the shoulder joint must be strong and balanced to reduce biceps tendon-tension overload. Here you can see that this athlete is in range.
- Imbalance with Triceps
If the triceps become disproportionately stronger—particularly in pitchers seeking more extension velocity—the biceps may not decelerate the arm effectively, increasing elbow stress and risk for valgus extension overload.
In this example from our Certified ArmCare Specialist Course, single-arm triceps training is focused on overhead actions. Elbow extension velocity is a factor in throwing at high speeds, so if you train it with exercises such as this one, you must create balance in the program by integrating biceps work.
Biceps + Grip Strength = Elbow Integrity
A strong biceps doesn’t work alone. It correlates highly with grip strength, particularly for resisting valgus torque—the force that attempts to separate the inner elbow during the late cocking and acceleration phases of a throw.
- Biceps contraction stabilizes the forearm in supination, which is generally the wrist position when the arm is lying back to its maximum external rotation position.
- The flexor-pronator group, along with the biceps, forms a protective net around the ulnar collateral ligament (UCL).
- Although it is unclear in academic research as an exact association, anecdotally, I have seen a strong connection between biceps strength and grip strength that can help raise our 3-finger grip used in testing with the ArmCare.com platform. The benefit of having strong biceps that can stabilize and decelerate is that it reduces fatigue to the smaller muscles of the forearm, which can maintain spin rates, ball velocity, and continued support of the inner elbow.
Gripping the handles with a three-finger grip has advantages in training the smaller forearm muscles that help stabilize the elbow, along with the biceps. In our Certified ArmCare Specialist Course, we talk about how to integrate this type of training safely to reduce overuse of the muscle, maximize strength, and minimize fatigue.
Key Takeaway: Don’t Skip Biceps Day
For throwing athletes, the biceps are more than cosmetic. They’re performance regulators, joint protectors, and force absorbers. In our education, we have multiple sections on the role of the biceps in throwing mechanics, training, and injury prevention.
Key Actions:
- Train both heads with multi-planar movements (arms up, down, and to the side)
- Develop eccentric and isometric biceps strength
- Balance grip strength, biceps strength, and shoulder stability
- Monitor triceps-to-biceps training ratios in high-velocity throwers
- Continue to correct shoulder imbalances to reduce load on the biceps tendon
In short, if you want a healthy arm and a long career on the mound or the field, your biceps better be doing more than just flexing for the mirror.
Strength Matters Most folks.
Ryan
Ryan@armcare.com
