4 Effective Subscapularis Stretches and Exercises

First, some anatomy!

Subscapularis Anatomy

The subscapularis is one of four muscles that make up the rotator cuff. The main function of all rotator cuff muscles is to stabilize the humerus (ball) in the glenoid fossa (socket) of the shoulder. Below is an image showing the four muscles of the cuff. For reference, you are looking at a right shoulder.

One unique aspect of the subscapularis muscle is that it is the only rotator cuff muscle whose action is to internally rotate the arm. Think: standing with your elbow at 90 degrees and bringing your hand to your belly. This is a relative internal rotation of your arm (the humerus) to your body. Out of the four rotator cuff muscles, the “subscap” is the largest, and strongest. The naming of the muscle can give you an indication of where it lives.

“sub”= under

“scap” scapula (shoulder blade, or wing bone)

This muscle is the largest, and strongest rotator cuff muscle. It is also the least likely to be injured.

Interestingly, the shoulder is inherently unstable. However, this is a tradeoff that mother nature has deemed acceptable to maximize shoulder function. We sacrifice some stability in our shoulders in order to move them through a larger range of motion, for activities like throwing, reaching, and pulling objects towards our body. This is in contrast to our hip joint; we have a tremendous amount of stability, but the range of motion is limited. A hip dislocation requires a violent mechanism of injury, such as a motor vehicle accident or a fall from a ladder.

Enjoy my crude sketch of the shoulder vs hip joint below.

One of my favorite examples of extreme shoulder motion occurs when a baseball pitcher is throwing a ball. Their arm goes from end-range external rotation to internal rotation extremely fast. During this movement, the subscapularis is required to produce a tremendous amount of force, quickly.

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Pain and Dysfunction of the Subscapularis Muscle

The subscap is the largest and strongest rotator cuff muscle. This is one reason why it is the least likely to get injured. The demographic that is most likely to experience dysfunction with this muscle is in young males, particularly those who do a lot of overhead shoulder movements or end-range external rotation.

How to Figure out if your Subscap is Dysfunctional

As a physical therapy student graduating in May, I feel obligated to say that if you suspect something is wrong with your shoulder and it is preventing you from completing activities that are important to you, you should get it examined by a healthcare professional. A physical therapist is the perfect person to give you a full examination and make a plan to increase your function and reduce your pain. However, I will give you a few tools to self-assess your shoulder if you are dealing with a minor ache or pain so you can decide if you can manage on your own.

Subscapularis Exercise: The Lift-Off Test

We use this to assess the function of someone’s subscap. You should be able to lift your hand away from the small of your back. If you can’t, then you might have a tear or partial tear of your subscap muscle. As you can see from the video, I have a harder time doing this on my right side. However, I have no pain and I am a baseball player, so this is not an unexpected finding! Our bodies adapt to the demands we place on them over time, so I am not too worried.

Other signs and symptoms of subscap dysfunction include pain or discomfort on the front part of your shoulder. This could be during movements, such as external rotation where the subscap will be stretched.

The subscapularis could also be tight. In this case, you would see less range of motion on the affected side. Stretching or doing some manual therapy to the subscap muscle could be beneficial if you fall into this category.

Subscapularis Stretch

Holding a towel, use your unaffected arm (in this case, my left arm) and grasp the towel with the affected one (my right). Gently use your unaffected arm and pull the other side up. This will apply a gentle stretch to the subscap. hold for 30-60 seconds, rest, and repeat 2-3 times.

Anybody can benefit from rotator cuff strengthening. Since the action of the subscap is to internally rotate the arm, we want to target internal rotation exercises.

If you have some pain:

Isometrics is a good place to start. Stand with your arm bent at 90 degrees, and press your wrist gently into the wall for 10-15 seconds. This is a good place to start for a “hot” subscap, and can provide some pain relieving effects. This is especially true in an injury to the tendon.

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Subscapularis Strengthening Progression: Banded Internal Rotation

Stand with a band or cable and complete a full internal rotation with your shoulder. A good place to start is 2-3 sets of 12-15 reps. Use fatigue as your gauge, you want the muscle to feel tired by the end of each set! 

Now that you have a deeper understanding of shoulder anatomy and have some ways to determine the health and function of your subscapularis muscle, you can use these exercises to address your impairments!

If you enjoyed this post, learn about Rhomboid Muscle Pain as well as Teres Major and Minor Exercises.

Sources:

[1] https://paincareclinic.co.uk/other/getting-around-rotator-cuff-injuries/

[2] https://www.researchgate.net/figure/Maximum-shoulder-external-rotation-occurs-at-the-end-of-the-arm-cocking-phase-as-the-arm_fig7_360202459

[3] https://www.verywellhealth.com/isometric-shoulder-exercises-2696516