More than 20 years since Sir Mix-A-Lot celebrated "big butts" in Baby Got Back, celebrity society has seen an upswing in curves.

Leading the charge are the likes of Kim Kardashian, Rihanna, Iggy Azalea and Nicki Minaj. But the Neil Armstrong of the big booty brigade is J.Lo, and she has been at pains over the past month to ensure everybody knows it.

The 45-year-old singer, actor and American Idol judge has been posting her posterior all over Instagram with the hashtag "#jlobooty" in an attempt to not only plug her new single but to remind her contemporaries of the path her curves carved in the mainstream during the noughties.

However the Booty singer can thank the new breed of ladies who don't appear to be self-conscious about their behinds like she once was.

For her first album cover in 1999, Lopez wore gold hotpants but was photographed sitting down. Fast forward 15 years and she has done a 180, with the cheeky cover art for her latest single. She even cut Pitbull's verses and replaced him with Australian rapper Azalea, in the song and on the cover.

The song includes the lyrics "Big, big booty / What you got a big booty (Work) / Big, big booty / What you got a big booty (Shake that)" and follows Minaj's latest offering – Anaconda which samples Sir Mix-A-Lot's ditty .

So how is it that 'back' came back?

"I don't think so much that the butt is back as that it has finally moved from African-American culture to white American culture and from there into societies impacted by American culture," Curtin University professor of cultural studies, Jon Stratton, said.

"It is only recently that white women have begun to feel comfortable with big butts. In the mainstream this has, I think, to do with African-American music videos celebrating big butts."

But it was a somewhat inferior posterior that changed the trend.

"The turning point was Miley Cyrus' rather sad attempt at twerking. Not only has she got a small butt but she has little sense of rhythm and next to no ability to perform African-American dance moves that come from the hips. However, and perhaps because of these things, she was able to help make big butts and twerking more acceptable to white girls," Professor Stratton said.

While J.Lo, Minaj and co celebrate their assets, the fixation with the butt is also having an impact on fashion trends as Australia prepares for swimwear season.

Gold Coast based designer of swimwear and leggings label Molly & Polly, Kristen Beck has noticed a shift from customers requesting boy-leg briefs to a more Brazilian hi-cut.

"The butt is huge right now," Ms Beck told Fairfax Media after her showcase at the Brisbane Fashion Festival.

"Social media is partly responsible. The amount of squat challenges that are floating around out there at the moment is having an impact on shoppers as are the images of strong, toned girls which is inspiring. The booty is back.

"This season we've altered the cut to be a little bit more skimpy, not Brazilian but more bikini as it really flatters the bottom. You'll notice some of the girls with the biggest booties wear the higher cut Brazilian bikinis because they look awesome. The granny pants [boy legs] give you a saggy bum because it doesn't sit right so that's why I've given all my briefs, even the high-waisted ones, some Brazilian flavour this season."