The genesis of much of the ab work we do these days probably lies in the work done in an Australian physiotherapy lab during the mid-1990s.

The researchers, hoping to elucidate the underlying cause of back pain, attached electrodes to people’s midsections and directed them to rapidly raise and lower their arms.

In those with healthy backs, the scientists found, a deep abdominal muscle tensed several milliseconds before the arms rose. The brain apparently alerted the muscle, the transversus abdominis, to brace the spine in advance of movement. In those with back pain, however, the transversus abdominis didn’t fire early. The spine wasn’t ready for the flailing. It wobbled and ached. Perhaps, the researchers theorised, increasing abdominal strength could ease back pain.

Thereafter, the idea leaked into gyms that core health was “all about the transversus abdominis,” said Thomas Nesser, an associate professor of physical education at Indiana State University.

Personal trainers began directing clients to pull in their belly buttons during crunches.

But there’s growing dissent among sports scientists about whether all of this attention to the deep abdominal muscles is even safe. An article published in the The British Journal of Sports Medicine last year asserted that some of the key findings from the first Australian study may be wrong. Moreover, even if they were true for people in pain, they may not apply to the fit, whose trunk muscles weren’t misfiring in the first place.

“The idea has reached trainers and through them the public that the core means only the abs. There’s no science behind that idea,” maintains Stuart McGill, professor of spine biomechanics at the University of Waterloo.

... contd.