Sexism Or Science? AFLW Investigates If Players' Periods Linked To ACL Injuries

A spike in career-ending knee injuries to its female players has prompted the AFLW to investigate whether there's a link between ACL injuries and menstrual cycles.

On Friday night Demon Ainslie Kemp became the eighth AFLW player to rupture her ACL since the start of pre-season in November.

It's believed women are two to 10 times more likely to be felled by the knee injury compared to their male counterparts, and the League is eager to determine whether there's a link between the female menstrual cycle and the season-ending injury.

AFL women’s football chief Nicole Livingstone confirmed her support for the measure, saying the sport is "keen to explore this further".

The League is working alongside the Players’ Association and La Trobe University to research possible correlations.

But the news received a few raised eyebrows on social media, with many users claiming women shouldn't be playing the sport at all.

"Women need to understand it’s a man's game, they need to forget it. It isn’t going to survive at the standard of the game they are putting out," one Twitter user wrote.

Sexism aside, according to one expert, there is plenty of rhyme to the AFLW's reason.

Associate professor at Melbourne University Adam Bryant told 10 daily that there's a definite link between the female menstrual cycle and lower limb injuries, particularly to the Achilles tendon.

He explained this is because the muscles in the lower leg become more flexible during particular stages of the cycle, like ovulation.

"During ovulation females reach peak estrogen and progesterone levels," he said.

"However, we also tested another group who were using the pill and their fluctuations disappeared."

Prof Bryant said there have been various studies done which indicate the oral birth control pills can decrease the risk of injury.

Demon Ainslie Kemp is the latest casualty, rupturing her ACL on Friday night. Image: Getty

This is particularly the case with monophasic birth control -- a type of oral contraceptive where each pill is designed to deliver the same level of hormone throughout the entire pill pack.

Some studies suggest taking the pill could reduce the risk of ACL injury by up to 20 per cent.

"Research shows to reduce injury you should reduce estrogen levels and engage in strengthening and flexibility to help control these types of things," he said.

"Basically getting that right and the hormonal environment right will help."

Prof Bryant added there are certainly "danger weeks" within a cycle, generally from ovulation, which occurs mid-cycle from about day 14 onwards.

But he acknowledges this is a "multi-factorial" issue which is about much more than than just controlling hormones.

"Women have different lower limb biomechanics to men and because of that they typically have a knocked knee posture when they land, putting a strain on their ACL."

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Prof Bryant also bases much of his studies looking at the influence of athletic footwear on lower limb biomechanics of girls going through puberty.

"No one has really looked at the effect of it," he said.

"We're looking at 100 girls who are at different stages of puberty and their movement patterns.  Some of these movement patterns get worse from 16 (years old) upwards.

"So we've started to look at ways to design footwear to combat landing with a common knocked-knee posture when they're exposed."

Given the AFLW is in its infancy, many of its players had never picked up a footy until just a few years ago and have mostly been recruited from other sports like basketball, netball, hockey or soccer.

Adelaide's Erin Phillips ruptured her ACL in last year's grand final. The former Opal made the transition from basketball to footy. Image: AAP

Prof Bryant said this means their bodies are also taking some time to adjust to the new movements.

"That's the reality of a new sport. The men have been playing since they could walk but many of the women have picked it up after playing different sports."

The AFLW wouldn't be the first women's league to investigate the link between the two.

Just last week, FA Women's Super League club Chelsea released a statement saying it would tailor its training sessions around the female players' menstrual cycles.

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Chelsea Manager Emma Haynes said staff designed players’ individual plans around the phases of their menstrual cycle, with the belief that factoring it into training and nutrition regimes could help control weight fluctuations.

She explained reducing these fluctuations could help lessen a player's susceptibility to soft tissue injuries, such as ACL damage.

"The starting point is that we are women and ultimately we go through something very different to men on a monthly basis," she said in a statement posted to Chelsea's website.

"We have to have a better understanding of that because our education failed us at school. We didn’t get taught about our reproduction systems."

Last year Hayes met Dr. Georgie Bruinvels who developed an app called FitrWoman for sports science company Orreco.

The app allows women to keep track of information regarding their menstrual cycle which is logged and monitored.

Chelsea players are encouraged to use the app.

"The menstrual cycle is an inflammatory process and excess inflammation can result in an injury," Dr Bruinvels said.

"It’s not solely down to high levels of oestrogen, but tracking the cycle is also very important in terms of bone-injury risk."

What the AFL plans to do if they uncover a definitive link is unknown, but it's evident something needs to be done, and done now, to reduce the likelihood of these season-shattering injuries.

10 daily has contacted the AFL for comment.

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