The Teres Major is a small yet powerful muscle that contributes significantly to back thickness and shoulder function. It is often nicknamed the “Lat’s little helper” due to its synergistic action with the much larger Latissimus Dorsi muscle. Strengthening the Teres Major specifically enhances the aesthetics of the upper back and improves shoulder joint stability. Accomplishing this requires moving beyond general back exercises and implementing targeted movements and precise form adjustments. This focused approach ensures the smaller muscle is fully engaged, rather than being overpowered by the Latissimus Dorsi.
Anatomy and Role of the Teres Major
The Teres Major is positioned on the posterior surface of the shoulder girdle. It originates from the lower part of the scapula’s inferior angle and lateral border. Its fibers cross the shoulder joint to insert on the medial lip of the intertubercular groove of the humerus (upper arm bone). This anatomical path dictates its primary functions for arm movement.
The muscle performs three main movements at the shoulder joint: adduction, extension, and internal rotation. Adduction pulls the arm toward the midline, while extension moves the arm backward (e.g., during a pulling motion). Internal rotation turns the arm inward toward the body. Since the Teres Major shares these three actions with the Latissimus Dorsi, exercises emphasizing these movements are effective for both muscles.
Targeted Exercises for Teres Major Strength
To specifically target the Teres Major, exercises must isolate the shoulder joint’s extension and adduction functions while minimizing bicep and forearm contribution.
Straight-Arm Cable Pulldown
The Straight-Arm Cable Pulldown is the most effective isolation exercise because it removes elbow flexion. Stand facing a high cable pulley, grasp a straight bar or rope with arms nearly straight, and pull the attachment down in an arc toward the thighs. Execute the motion purely through shoulder extension, maintaining only a slight bend in the elbow.
Single-Arm Dumbbell Row
The Single-Arm Dumbbell Row can be modified to heavily recruit the Teres Major. This unilateral movement allows for greater focus on the contracting side. The setup involves placing one hand and one knee on a bench, with the torso parallel to the floor, holding a dumbbell in the opposite hand. Focus on pulling the dumbbell toward the back hip or waist, rather than toward the chest or mid-ribcage.
Underhand-Grip Lat Pulldown
This variation shifts the emphasis of the traditional pulldown movement. Using a supinated (underhand) grip with a shoulder-width or slightly narrower hand position increases Teres Major activation compared to a wide, overhand grip. Focus on bringing the bar to the upper chest, ensuring the elbows are driven down and back along the sides of the torso.
Form Adjustments for Isolation and Activation
The difference between training the Latissimus Dorsi and isolating the Teres Major lies in the fine-tuning of exercise form. When performing any pulling movement, the intention should be to drive the elbows down and back, imagining they are being tucked into the back pockets. This specific elbow path promotes shoulder adduction and extension, the main functions shared by both muscles.
To further bias the Teres Major during rows and pulldowns, a neutral or supinated grip is preferred. This grip naturally encourages the arm to internally rotate slightly, aligning with the Teres Major’s function. Focus on initiating the pull by depressing the shoulder blade (pulling it down away from the ear), rather than retracting it forcefully toward the spine. Excessive retraction primarily engages the rhomboids and middle trapezius. Depression and slight protraction at the top of the movement allow for a deeper stretch and subsequent contraction of the lower back muscles. Consistent application of these precise cues and maintaining a strong mind-muscle connection are necessary for successfully isolating and strengthening the Teres Major.