Can Bras Cause Thoracic Outlet Syndrome? Bra Strap Syndrome.

Neurogenic thoracic outlet syndrome (TOS) – the kind that involves your nerves – makes up more than 90% of all this condition’s cases. And, unfortunately, it’s more prevalent in women. Now, why is that? Can bras cause thoracic outlet syndrome? (1)

Let me answer the latter question first: Ill-fitting bras can contribute to the development of TOS.

Needless to say, there’s more to that answer. But, to truly understand it, you also need to have an understanding of why thoracic outlet syndrome is more common in women.

So, bear with me here. I promise it won’t take long.

bras cause thoracic outlet syndrome
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Why is thoracic outlet syndrome more common in women?

It all comes down to what causes thoracic outlet syndrome in the first place which is a compressed neurovascular bundle at the lower part of your neck.

For a woman such as yourself, slouched postures and less developed muscles is a more common theme than with your male counterparts. This is particularly true if you have large breasts.

This posture and muscle weakness, in turn, rounds your shoulders and brings your clavicle closer to your first rib. This narrows the gap that your nerves and blood vessels pass through, thus leading to thoracic outlet syndrome.

Now, you might be asking: What does this have to do with bras?


An ill-fitting bra can lead to thoracic outlet syndrome

From straps that dig into your shoulders, to the underwire digging into your skin, and the wrong cup size… all these things scream ill-fitting. And, to prevent TOS, you should really pay attention to your bra’s shoulder straps and cup size.

How bra straps cause thoracic outlet syndrome

This issue has actually been around for quite a long time now. As a matter of fact, a study way back 1986 already described “tight, narrow brassiere straps” as a common cause for thoracic outlet syndrome. (2)

The way this happens is that the thin, tight strap applies a downward pressure that directly pulls your clavicle closer to your rib. Which, as already stated, is how a lot of TOS conditions start.

How the wrong cup size can lead to thoracic outlet syndrome

The issue with wearing the wrong cup size and straps that are too tight is rooted in the same issue: Improper support.

With a cup size that’s too big, your bosom isn’t as supported as it should be. Your straps now have to compensate for that lack of support – which circles back to the problem of your straps being too tight.

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Tips to prevent thoracic outlet syndrome for women

1. Wear bras with broad straps

Unlike its thinner counterpart, wide straps don’t tend to dig into your skin.

Broad straps are better capable of dispersing the weight of your breasts. This, in turn, makes them more supportive.

Thinner straps, on the other hand, don’t have the luxury of spreading out the weight of your knockers. So, the downward force is more concentrated to a single, tiny spot.

2. Go strapless

Whenever possible, wearing a strapless bra can be both comfortable and functional. Plus, not having a strap essentially forgoes the risk of your clavicle being pulled closer to your rib.

In many cases, strapless bras also promote better posture because there’s less stress on your shoulders and scapular muscles.

If you’re well-endowed, consider getting a strapless long line bra. These provide better support and can also be better for both your figure and posture.

strapless bras for thoracic outlet syndrome
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3. Lose the bra entirely (until symptoms are done and dusted)

While this might be a polarizing subject, there’s research to support that not wearing a bra might be better for the long-term.

One such research from Professor Jean-Denis Rouillon suggests that wearing bras deprive your chest and postural muscles of strength and tone because they don’t have to counter the pull of gravity. So, over the long term, it may cause your breasts to sag.

For TOS, building the strength of your chest and postural muscles helps bring down the risk of developing the syndrome. And, it supposedly results in perkier chests.

Truth be told, however, this is just one study and there really isn’t much else to formulate a definitive conclusion. So, take this with a grain of salt.

4. Work on your posture

Regardless if going braless has its perks (no pun intended), working on your posture will only do you good.

For those of you with thoracic outlet syndrome, the large focus will be on reversing your poor posture while also strengthening your chest.

However, there are many aspects to a good posture. So, I highly recommend you work with a professional (e.g. a physical therapist, trainer) so you can get properly assessed.

5. Get professionally fitted

A study says that about 70% of women wear poorly fitted bras. (3)

Needless to say, that’s a huge number and I think it’s a shame. There’s a huge population of women who opt for breast reduction surgery because they don’t feel comfortable wearing their bras. But, the truth is really that a lot of these same women only need a professional fit. (4)

You may or may not be a part of this population but I can assure you that there are virtually no cons to consulting a professional fitter.

Plus, a properly fitted brassiere – with the right cup size, bra straps and all that – can help keep you away from thoracic outlet syndrome.

Tips from a Bra Fitter

6. Avoid wearing sports bras or tight bras all day

A sports can be the perfect medium between functionality, comfort, and style. You can exercise in it without worrying about jiggling; You can wear them casually at home while on a meeting or simply lounging about, and you can even wear them while hanging out.

However, the problem begins when you rely too much on sports bras – or any bra for that matter – and it goes back to the hypothesis of bras depriving your chest and postural muscles of strength and tone.

Whether or not that’s a universal rule, your bosom and postural muscles can definitely benefit from a braless break – and that might just be enough to keep you away from TOS.

My final thoughts on whether bras cause thoracic outlet syndrome

In a nutshell, it isn’t accurate to say that bras cause thoracic outlet syndrome. Rather, it’s ill-fitting brassieres that lead to TOS because of improper support.

A thin strap that’s too tight can pull your clavicle and first rib closer together. A cup-size that’s too big will also force you to compensate using the straps which, again, circles back to the same problem.

To minimize the risk, I highly recommend getting professionally fitted and then buying yourself a few new bras. Preferably ones with brad straps. Apart from that, working on your strength and posture will also do you some good.

Research + Resources:
  1. Kaplan J, Kanwal A. Thoracic Outlet Syndrome. [Updated 2021 Apr 21]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from:
  2. De Silva, M. “The costoclavicular syndrome: a ‘new cause’.” Annals of the rheumatic diseases 45,11 (1986): 916-20. doi:10.1136/ard.45.11.916
  3. Wood, Katherine et al. “Breast size, bra fit and thoracic pain in young women: a correlational study.” Chiropractic & osteopathy 16 1. 13 Mar. 2008, doi:10.1186/1746-1340-16-1
  4. Greenbaum, A R et al. “An investigation of the suitability of bra fit in women referred for reduction mammaplasty.” British journal of plastic surgery 56,3 (2003): 230-6. doi:10.1016/s0007-1226(03)00122-x

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