The triceps brachii is a muscle on the back of the upper arm composed of three distinct sections. One section, the medial head, is often overlooked in training. Targeting this specific head is important for achieving complete arm development and ensuring strength across the full range of elbow extension. The medial head functions as the primary elbow extensor, making its specific recruitment a goal for maximizing arm size and functional strength. This guide focuses on the techniques and exercises required to maximize the recruitment of the medial head.
Understanding the Triceps Muscle Group
The triceps brachii, meaning “three-headed muscle of the arm,” covers the posterior side of the humerus. The three heads—long, lateral, and medial—converge at the elbow to form a single tendon attaching to the ulna.
The medial head originates low on the posterior humerus, unlike the long head which begins at the shoulder blade. Because the medial head does not cross the shoulder joint, its function is purely to extend the elbow. This anatomical distinction makes the medial head the workhorse of the triceps, consistently active during all elbow extension movements, especially those requiring precision.
It is often described as the deep head because its location is partially covered by the other two heads. While complete isolation is impossible, specific training mechanics can significantly bias its activation over the long and lateral heads.
Technique Focus for Medial Head Activation
The most effective way to bias the medial head involves controlling three primary biomechanical factors: grip orientation, elbow position, and the range of motion. A supinated, or reverse grip, is a powerful technique for increasing medial head activity. This wrist position slightly de-emphasizes the lateral head, resulting in higher measured activation of the medial head during pushdown movements.
Maintaining the elbows tucked close to the sides of the torso promotes medial head recruitment. This position reduces the involvement of the long head, shifting the focus toward the two heads that originate on the humerus. The medial head is composed of a higher proportion of slow-twitch muscle fibers, meaning it responds well to higher repetition ranges and time under tension.
Achieving a full elbow lockout at the end of the extension phase is a primary mechanism for maximizing medial head recruitment. The medial head shows greater activation at shorter muscle lengths, engaging most strongly as the arm approaches full extension. Pausing briefly in the fully straightened position ensures a peak contraction. Controlling the tempo, particularly the eccentric (lowering) phase, ensures constant tension, which is effective for this fiber type.
Effective Exercises for Targeting the Medial Head
The Reverse-Grip Cable Pushdown is the most direct isolation exercise for the medial head, incorporating the necessary supinated grip and tucked elbow position. To perform this, attach a straight bar or EZ-bar to a high pulley and grasp it with an underhand grip at about shoulder-width. Keep the upper arms stationary and pressed against the sides of the body, then push the bar down until the elbows are completely straight. This full extension is necessary to fully engage the medial head, and the reverse grip enhances this focus.
The Close-Grip Bench Press is a compound movement that effectively recruits the medial head due to the narrow hand placement. Using a grip closer than shoulder-width shifts the load significantly from the chest and anterior shoulders to the triceps. This exercise demands a strong lockout, ensuring heavy recruitment of the medial head as a primary extensor at the end range of motion. The elbows must be kept relatively tight to the body throughout the movement to maintain triceps tension.
The Dumbbell Tate Press is an isolation movement that forces the medial head to work through a challenging range of motion. Lie on a bench holding a pair of dumbbells straight above the chest with palms facing down and the dumbbells touching. Initiate the movement by bending the elbows and lowering the dumbbells toward the chest, keeping the upper arms perpendicular to the floor. This motion requires the medial head to stabilize the elbow joint and forcefully extend the arm from a deeply flexed position.
The Diamond Push-Up is a bodyweight exercise that forces the hands into a narrow, triangular position directly beneath the chest. This narrow base places maximum mechanical stress on the triceps, particularly the medial and lateral heads. Achieving a full elbow lockout at the top of the movement is important for emphasizing the medial head’s role as the final elbow extensor.