The subscapularis is the largest and the strongest of the four rotator-cuff muscles that act on your shoulder, stabilizing it and facilitating inward rotation of the humerus. It is the most-used muscle in the shoulder. Let’s first discuss its functional anatomy before delving into the different exercises that you can use to target it.
What is the Subscapularis?
A triangular-shaped muscle located in the subscapular fossa. The name ‘subscapularis’ means under (sub) the scapula (the shoulder blade). The muscle originates beneath the scapula. Its fibers form a tendon that inserts into the should joint capsule and the lesser tuberosity of the humerus.
The subscapularis is innervated by the subscapular nerve and supplied by the subscapular artery.
Action / Function
Contraction of the subscapularis will cause internal (medial) rotation and depression of the humerus at the shoulder joint. In certain positions, it also helps in adducting and extending the shoulder joint.
The position of your arm has a significant effect on the actions caused by the subscapularis. For instance, when your arm is raised, the muscle pulls the humerus forward and downward; but when the humerus is in a fixed position, it causes abduction of the lower border of the scapula.
As part of the rotator cuff or intrinsic shoulder muscle group, the subscapularis plays a crucial role in stabilization of the shoulder by preventing anterior and superior translation of the head of the humerus.
Exercises for the Subscapularis
Now that you know the anatomy and function of the subscapularis, let’s go back to the meat of the matter and discuss the exercises for this particular muscle. Note that most of the exercises are for strengthening purposes.
Performing isometric exercises that engage the subscapularis involves contracting it for 5-10 seconds at a time without any considerable movement on your shoulder joint. These exercises are typically recommended by physical therapists as part of a rehabilitation program for an injured rotator cuff.
Lay on your back and place your left elbow approximately 6 inches away from your side and flexed to 90 degrees. In this position your forearm should be pointing upward. Place a thick towel next to your hip on the same side then internally rotate your shoulder to put your hand on top of the towel. Press downward for 5-10 seconds. Relax and then move your elbow 3 inches laterally, farther away from your side. Repeat the movement.
Do two more reps – once with your elbow on the same level as your ear and once with your upper arm pointing away from your shoulder. Repeat the same movements with your right arm.
Side-Lying Internal Rotation
You’ll need a table and a dumbbell for this exercise. Lie on your left side and hold the dumbbell in your left hand. Tuck your elbow into your belly, with your forearm pointing forward and extended over the edge of the table. Lift the dumbbell until your forearm touches your abdomen, then slowly lower it and repeat. Perform at least 8 repetitions, then turn over and switch arms.
Resistance Band Exercises
You can perform different resistance band exercises in order to strengthen the subscapularis. The first one is similar to the side-lying internal rotation exercise, but you do it from a standing position. Hold one end of the resistance band, with the other end secured to a sturdy object. The resistance band should be positioned at about the same height as your belly-button.
The second is the diagonal exercise. Stand with your right foot in front of your left and the free end of the resistance band in your left hand. Your left arm must be pointing sideways, with your elbow slightly flexed and your palm facing forward. Internally rotate your arm and move your hand downward to stretch the band until your left hand is in front of your right hip. Slowly return to the starting position and repeat. Perform the same exercise with your right arm.
This is considered by many as the best exercise for the subscapularis muscle. Assume the push-up position, either from your knees or from your feet. Doing the exercise on your knees is a little easier.
- Push-Up Plus – Knees
Place your hands directly beneath your shoulders. Keep the tension in your scapulae and mid back, then at the end position with your arms fully extended, push up a little harder by trying to move your body further away from your hands.
- Push Up Plus – Toes
Perform this exercise in a slow and controlled manner. Hold for a second before lowering your body. Start with 5 repetitions the progress to 10 reps. Start from your knees until you are comfortable, then progress to your feet/toes. Avoid collapsing through the mid back or dropping your head.