Many women suffer breast pain or discomfort during everyday life and exercise regardless of bra size, age or health,because their breasts are not properly supported- University of Wollongong.
When Professor Julie Steele first published a scholarly review on the science of breast biomechanics, which found that breast bounce caused 50 per cent of women pain during exercise and daily life, postcards flooded in from around the world.
"It was the first time in my 30 years working on injury prevention that I've received handwritten postcards," the Sydney Morning Herald quoted Professor Steele as saying.
"Women from all over the world, from all walks of life, wrote to me, often with stories about their discomfort, thanking me for taking this topic seriously," she revealed.
Most women assume supportive sports bras will be uncomfortable.
"But they don't have to be," said Professor Steele, who runs Breast Research Australia (BRA), one of only two independent research institutes of its kind in the world.
Researchers in Britain estimate that during sport, the average breast can move 21 centimetres (about the length of a box of tissues) in a figure eight movement.
Breasts don't only move up and down, they move side to side, and even in and out. Given the average breast weighs about the same as 1.2 litres of milk and is held in place by skin and Cooper's ligaments, that's a lot of bounce or slide.
Professor Steele, who is the associate dean of research at the faculty of health and behavioural sciences of Wollongong University, said there were "significant medical implications of inappropriate breast support".
Poorly adjusted bra straps can cause headache, backache, and numbness and tingling in the hands because the straps apply excessive pressure to nerves that cross the shoulder and innervate the hand.
Steele has written 13 papers on the science of breast biomechanics.