Back Pain and the Wrong Bra Size

How a bra can contribute

The straps carry the load

When a band is too loose it cannot hold the bra up, so the weight of the breasts transfers to the straps. That is a downward pull on the tops of the shoulders, all day. People describe grooves in the shoulders and an ache across the upper back and into the neck. See bra straps digging into your shoulders.

The breasts are not supported

Cups that are too small, or a band that rides up, leave the breasts hanging lower and further forward than they would in a bra that fits. Many people respond by rounding the shoulders or leaning back slightly, and hold that position for hours.

The band is too tight

A band that is too small restricts the ribcage and can make the muscles around it sore. This is less common than a loose band.

What research shows, and what it does not

The honest position is that this is not a heavily researched area, and strong claims in either direction are hard to support.

• Research groups, including the University of Portsmouth's breast health researchers, have studied bra fit and breast support, and musculoskeletal discomfort is among the complaints reported by women with larger breasts.
• A Portsmouth study in Ergonomics found that the traditional tape-measure fitting method put most participants in a band too large and a cup too small. That is the pattern that moves weight onto the straps.
• A small 2008 Australian study of 30 young women with upper back pain found that 80% wore an incorrectly sized bra, and also found only negligible relationships between pain and bra fit.
• The Portsmouth study looked at how sizes are chosen. It did not test whether changing bra size relieves back pain, and it should not be quoted as proof that it does.

So a well-fitted bra is a sensible, low-cost thing to try, particularly if you have a fuller bust and strap marks. It is not an established treatment for back pain.

A quick check of your current bra

1. Slip the straps off your shoulders. If the bra drops, the band is too loose.
2. Look side-on. The band should be level front and back.
3. Check the cups after a scoop and swoop. Nothing should bulge over the top or sides.
4. Look at your shoulders after a day's wear. Deep grooves mean the straps are overloaded.

If any of these fail, the usual correction is a smaller band with a larger cup. Re-measure and then go through how a bra should fit.

Features that help with a heavier bust

• A firm band with three or four hooks
• Wide straps that you do not need to tighten hard
• Seamed cups with side support
• A leotard or U-shaped back, which holds the straps in place
• A properly supportive sports bra for exercise

When it is not the bra

If a bra that passes every fit check makes no difference after a couple of weeks, look elsewhere. Desk set-up, activity levels, muscle strength, sleep and stress are all common contributors, and the NHS has guidance on self-care for back pain. If the weight of your breasts causes ongoing pain despite a well-fitted bra, tell your GP. They can advise on physiotherapy and other options.

Frequently asked questions

Can the wrong bra size cause back pain?

A badly fitting bra can contribute to discomfort in the upper back, shoulders and neck, mainly by putting the weight of the breasts on the straps. It is rarely the only cause of back pain, and a new bra should not be expected to cure pain that has other origins.

What kind of bra is best for back pain?

One with a firm, well-fitted band, cups that fully contain the breasts, and wide straps that are not pulled tight. For larger cup sizes, a wider band with three or more hooks and side support helps.

Will a posture bra fix my back?

Bras sold for posture have crossed or reinforced back panels that can feel supportive. Evidence that they change posture in any lasting way is thin. A correctly sized ordinary bra is the first thing to get right.