A Source of Shoulder Pain: The Subclavius, Pec Minor, and Pec Major

The pec minor, pec major, and the subclavius are three muscles that can play an important role in

  • shoulder joint pain
  • neck pain
  • pain related to thoracic outlet syndrome, a condition where nerves get pinched as they pass through the thoracic outlet, an area loosely defined as your upper chest area, between the neck and the armpit.

The Subclavius

The subclavius is found between, and thus connects together, the first rib and the clavicle, better known as the collar bone.  Its importance lies in the fact that it can influence the movement and position of the shoulder joint.

Despite its importance, the subclavius isn’t well known or appreciated.

Once you understand its position and actions, it is unsurprising that the subcalvius can be a source of shoulder pain, not because it is sore or hurt, but because when it gets too tight it can pull the shoulder forward and down, thus misaligning the shoulder joint. Any time the gleno-humeral joint isn’t aligned properly, pain can arise.

I’ve read differing explanations as to how a subclavius can become tight:

  • Since the muscle moves your collarbone down and forward towards the first rib, perhaps prolonged sitting with your arms in front of you, as if sitting at a desk typing, can cause tightening.

    this is a picture of the subclavius, and muscle that can cause shoulder pain

    The subclavius connects your collarbone and first rib.

  • Some specialists believe that any type of trauma to the upper body can result in the possible contraction of many of the smaller muscles that connect the thorax/neck/skull complex. The subclavius would definitely fit that description.

There is also the aspect of breathing.

I was first introduced to the subclavius at a seminar in New York City. It was breathing course given by the Postural Restoration Institute®.

The PRI explanation of a tight subclavius is that it occurs, at least some of the time, due to faulty breathing patterns. When the diaphragms aren’t being used properly for respiration, often times we develop compensatory breathing patterns to assist us in drawing air into our chest. Lower back and neck muscles are often recruited to help us breath.


The Scalenes

A family of neck muscles, the scalenes, are often recruited by the body during compensatory (read:faulty) breathing. The scalenes attempt to enhance airflow into our chest by pulling our rib cage up, via their attachment to the first two ribs.

this is a picture of the scalenes which can cause shoulder pain

Scalene muscles seen from the front. Notice how these neck muscles attach to the first two ribs.

Expansion Rules

We want our rib cage to expand outwardly as we inhale. This outward expansion involves a degree of upward movement, as you can see in the video below. But this upward movement is not the upward movement that occurs when the scalenes try to help. The scalenes “up” is a compensatory movement.


What can’t be seen on the video is that the individual ribs rotate up and down as the rib cage expands and contracts. Think Venetian blinds. They rotate up during inhalation (rib cage expansion) and down during exhalation (rib cage contraction).

If we lose the ability to expand our rib cage, which is fairly normal,  the scalenes will try to help us get air into our lungs via their upwards pull on the first two ribs. While it’s good to get air into our lungs, the compensatory methods chosen by our brain often produce unintended results.

If the first two ribs are constantly pulled up towards the clavicle the subclavius can get tight due to it being positioned between the clavicle and first rib. The subclavius is living in a consistently shortened positioned. It can’t sit back and relax. It’s always “on”.

As a result, the subclavius might not let go of the first rib, so the first two ribs can get stuck in this external (up) rotation rather than internally (down) rotating. We like ribs that can move both up and down. We don’t like ribs that are stuck in the “up” position.

The Pec Minor

The pec minor runs from the coracoid process of the scapula (the part the of the scapula that sits above and slightly in front of the shoulder joint) and travels down to ribs 3-5. When tight, as it often is on the right side, it pulls the shoulder forward and in towards the midline of the body. It often needs to be manually released. 

The Pectoralis Major

The pec major is one of every bodybuilders favorite muscles. Very few things are as impressive as a broad chest. However, the pec major can get tight. When it gets tight, it too, can have an impact on shoulder health. the pec major muscle can cause shoulder pain

The clavicular head of the pec major, the part that runs from the clavicle out towards the arm, lays just on top of the subclavius.

The Visual Impact

Another interesting aspect of this whole thing is that you will sometimes see one shoulder shorter than the other.

What I mean is that if you measure from the intersection of your clavicles, essentially the middle of your collarbone at the base of your neck, out to the edge of the shoulder, one side may be a significantly shorter distance than the other.

Two summers ago I noticed that my left shoulder measured one full inch longer than my right shoulder (I have since seen this phenomenon with two clients that I train. Each measured a full inch shorter on the right side than the left side)

visual effect of subclavius

Intrigued, I looked up how to manually release a subclavius. It turns out to be quite simple. All I had to do was take my thumb, forefinger, or middle finger and press underneath the collar bone in a “forward and up” movement. I started on the inside and worked my way out.

The moment I pressed on it, I knew something was tight because it hurt like hell. However, you gotta do what you gotta do. So I continued with my subclavius release for a minute or so. When I stood up and remeasured, I had gained an inch on my right side.

Or Was it My Pec Major?

To be honest, while I thought I was releasing the subclavius, it occurred to me afterwards that I could have been massaging my pec major. And perhaps it was a tight pec major that produced my short right shoulder. They occupy the same real estate, so to speak. To this day I still don’t know which one I released. Perhaps it was both.

After my pec/subcalvius release, I noticed a curious thing.

My whole body felt looser. I remember sitting down cross-legged very easily. It was never like that before.

Fight or Flight vs. Rest and Relax

How could the two be connected?

Well, the human body goes through cycles of tension and relaxation. Make a fist, then relax your hand. That would be tension and relaxation on a local level.

Yet this happens on a systematic level all the time.

You can think of it as central nervous system activity.

We have the sympathetic nervous system, the “fight or flight” state, and the para-sympathetic nervous system, the “rest and relax” state.

Often times, for any number of reasons, our bodies can be too dominant towards the sympathetic nervous system. This type of body often feels tight, rigid, inflexible, and tense.

Dysfunctional breathing patterns are associated with sympathetic nervous tone, aka tension.

If your first two ribs are being held up by the scalenes, it’s a sure bet that you have developed compensational, and dysfunctional, breathing strategies which will likely increase sympathetic nervous activity.

Slow concentrated breathing is one of the best ways to turn off sympathetic “fight or flight” nervous tone and get into a more para-sympathetic “rest and relax” state.

This is probably one reason why meditation promotes relaxation: the focus on the breathing, particularly the outbreath, which is more associated with “rest and relax” (while inhalation is more associated with “fight or flight”).

When I let my first rib break away from the collar bone and thus start acting like a first rib should, my breathing pattern would obviously change and a bodily system that was heavily biased towards “fight or flight” could finally “rest and relax”.

And if it was my pec major that I released, it still had an effect of repositioning a shoulder and opening up a smushed upper right chest area that had been closed down.


Even if one shoulder isn’t visibly shorter than the other, it can’t hurt to give yourself some manual therapy. And it’s always interesting to compare your right and left side, to notice any differences.

But a word of caution: ease into it.

If your subclavius or pec major is tight, it can be quite tender and painful if you press too hard. Also, there are many nerves that run underneath the outer portion of the scapula, and ultimately innervate your arms. So just don’t press too hard, particularly as you move further away from the middle, or you might start feeling some odd sensations in your arms and chest.

Chronic pain effects an estimated 100 million Americans, and I know this information could help them as it has helped me and my clients. Please consider clicking on the Facebook or Linkedin icons on the left to help spread the word.





  1. Asur says

    Hello, can you help me plz? I have subclavius pain about 5 moths but not serious pain i can workout too but when i finished my workout i feel more pain for 2 hours then gone. then pain just when i taught the subclavius muscle . What should i do ?

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