Women could be damaging their breasts by wearing the wrong kind of bras, researchers have warned.
The breast biomechanics research team at the University of Portsmouth discovered that some women's breasts could be damaged and fragile ligaments irreparably stretched by wearing the wrong bras.
The research team tested about 50 bra designs on hundreds of women over the past three years.
It found that, during exercise, breasts move up to 21cm – they move up and down, in and out and from side to side. Yet most bras are designed to limit just vertical movement.
Wendy Hedger, a member of the research team, said: "Many women have strong preferences for certain styles of bra and won't buy anything else.
"And some women cause breast pain or discomfort by not buying the right-sized bra. There's a social stigma about certain sizes; many women don't want to be seen as too small or too big, and buy a bra that doesn't fit well in order to be what they consider to be a normal size.
"Some women forget that their shape and size change, and they might have to go through several changes in bra size over their lifetime, especially after breastfeeding and the menopause."