Demystifying the Triceps Brachii
The triceps brachii, which is Latin for “three-headed muscle of the arm,” is a large, thick muscle located on the back of the upper arm. It is fundamentally responsible for straightening the arm at the elbow joint. The three heads—long, lateral, and medial—all have different points of origin but converge into a single tendon that attaches to the ulna, one of the forearm bones. While all three heads work in unison to extend the elbow, specific exercises can emphasize one head over the others to help with muscle balance, strength, and definition.
The Three Heads of the Triceps
The Medial Head: The Inner Part
The medial head, often referred to as the 'inner tricep' due to its position relative to the body, is the deepest of the three heads. It originates from the posterior surface of the humerus (upper arm bone), below the radial groove. Despite being mostly concealed by the other two heads, the medial head is a workhorse, particularly during elbow extension. It is consistently active during all types of elbow extension, whether it’s a light or heavy load.
The Lateral Head: The Outer Part
The lateral head is located on the outer side of the upper arm, contributing significantly to the muscle's classic 'horseshoe' shape when developed. It arises from the posterior surface of the humerus, above the radial groove. The lateral head is particularly active during forearm extension and is often the most visible of the three heads, especially when flexing the arm.
The Long Head: The Largest Part
The long head is the largest of the three and is the only one that crosses both the shoulder and elbow joints. It originates from the scapula (shoulder blade) and is found on the back of the arm, near the torso. Because it crosses the shoulder joint, it assists with both elbow extension and shoulder adduction, which is the action of pulling the arm back toward the body. This dual function makes it a crucial stabilizer for shoulder movements.
Why Understanding the Medial Head Matters
Targeting the medial head is vital for building overall triceps mass and power, as well as for elbow joint stability. While all triceps exercises engage the medial head to some degree, a balanced workout routine should include exercises that place specific emphasis on this muscle. Many people inadvertently neglect the medial head by relying too heavily on general pressing movements, which can lead to muscular imbalances. Incorporating a variety of exercises ensures comprehensive development of all three heads.
Exercises to Target the Medial Head
To ensure balanced triceps development, it is beneficial to include exercises that emphasize the medial head. A variety of grip positions and angles can help achieve this. Here are some effective exercises:
- Cable Triceps Pushdown (Reverse Grip): Using an underhand grip (palms facing up) during a cable pushdown shifts the focus slightly to the medial head.
- Dumbbell Tate Press: This exercise involves lying on a bench and pressing dumbbells together in an upward arc, providing excellent isolation for the medial head.
- Close-Grip Bench Press: While a compound movement, using a close grip places significantly more stress on the triceps, and the medial head is heavily involved in the pressing motion.
- Skull Crushers: This classic isolation exercise works all three heads, but can be particularly effective for the medial head, especially with a controlled, full range of motion.
Comparison of Triceps Heads
| Feature | Medial Head | Lateral Head | Long Head |
|---|---|---|---|
| Location | Deep, inner part of upper arm | Outer part of upper arm | Back of upper arm, near torso |
| Visibility | Least visible | Most visible, contributes to 'horseshoe' shape | Visible, adds to arm fullness |
| Origin | Posterior humerus, inferior to radial groove | Posterior humerus, superior to radial groove | Infraglenoid tubercle of scapula |
| Primary Function | Elbow extension, crucial for stability | Elbow extension, especially at high resistance | Elbow extension, shoulder adduction/extension |
| Key Target Exercises | Reverse-grip pushdowns, Tate press | Cable pushdowns, dips | Overhead extensions, kickbacks |
Proper Form and Technique
To effectively train the medial head and avoid injury, proper form is non-negotiable. When performing exercises like skull crushers or cable pushdowns, focus on a controlled, deliberate movement. Avoid using momentum and ensure the elbow is the primary joint moving. Keep your wrists in a neutral position to prevent strain. Incorporating proper form will lead to better muscle activation and prevent tendonitis, a common overuse injury in the elbow. Always warm up adequately before beginning any triceps workout.
Conclusion: The Importance of a Balanced Approach
Understanding what is the inner part of your tricep called is the first step toward a more comprehensive and effective arm training regimen. By recognizing the role of the medial head, along with its lateral and long counterparts, you can build a more balanced, stronger, and healthier upper arm. A well-rounded workout plan should include a mix of compound and isolation exercises that target all three heads. For more information on human anatomy and musculature, consider visiting reputable health education sites like the National Institutes of Health. By focusing on all three heads, you ensure functional strength and impressive definition from all angles. Remember to always listen to your body and train safely to achieve your fitness goals.
