When Isabel Huntington kicked truly for the Western Bulldogs at Fremantle Oval on Sunday night, she was mobbed by a group of team-mates who understood just how difficult her journey back to the field has been.

The former number one draft pick of 2017, who recently turned 20, has endured a brutal run of injuries, including a broken leg in 2015, her first injury to the anterior cruciate ligament (ACL) in 2016 and then, just a week after her debut in 2018, a second ACL — to the opposite knee.

In December last year doctors were concerned Huntington had again ruptured her right ACL during a training session. Scans revealed a sprain instead, which still meant more time off the field. With just seven weeks of AFL Women's league in 2019, it meant Huntington was at risk of missing yet another season of football.

She's not alone.

This year, five AFLW players have already ruptured their ACLs. Women are anywhere between two to five times more likely to rupture their ACLs in any sport when compared to men, but in AFLW the numbers are higher again. Women are 9.2 times more likely than men within the AFL system to sustain an ACL injury.

Western Bulldogs AFL player Isabel Huntington could not play while she recovered from a knee injury ( Supplied: Twitter )

The problem of 'cross-coding'

North Melbourne football club physiotherapist Melissa Haberfield that while the stats were concerning it was important to interpret them with caution.

"Traditionally there haven't been many pathways for women into professional leagues," said Ms Haberfield.

"So we're seeing a lot of athletes who are cross-coders and a lot of girls coming to the game in their late teens or even women in their late-20s kicking a footy for the first time.

"The thing we have to remember is that these data only come from two short seasons. We will see a change over the next while and the rates will drop when the sport becomes further professionalised."

She says this could explain in part why higher injury rates are emerging in the AFLW: "The girls aren't used to the 360-degree type of game that AFL is, and the movement patterns that are required to cope with that."

Contrary to what some may assume, Ms Haberfield says 70 per cent of ACL injuries occur in a non-contact position.

This means players are most likely to rupture their ACLs jumping and landing on one leg — which can cause the knee to collapse inward — or decelerating to stop and change direction. This can cause overstriding, and a twisting force through the knee. Correct technique can reduce the risk of being injured this way.

Isabel Huntington of the Western Bulldogs AFLW has struggled with ASL injury. ( AAP: David Crosling )

Hormones may also play a role

Professor Nigel Stepto from Victoria University's Institute of Health and Sport has been looking into the physiological factors that contribute to women's greater likelihood of rupturing their ACLs. He said accelerating the pathway to professional sport for women was a critical step.

"It would be remiss not to acknowledge that reproductive hormones and systems do have a subtle but different impact," he says.

Research has suggested that the period post-ovulation, when progesterone is high, coincides with an increased likelihood of injury. "But that's not for all women, and we don't yet have the confidence or evidence to say exactly what's happening (without the research and evidence base)."

Prof Stepto urges a strong movement towards full professional sport for women.

"Semi-professional sport makes things a lot harder for an AFLW player who does an ACL, because not only is her sporting career impacted, it's her main income stream as well. In that respect we either need to move towards more professional sport where income is generated fully from that sport, or they really need good support to help these (women) recover properly."

A diagram of the knee showing the anterior cruciate ligament or ACL ( Wikipedia.com )

New program targets knees

The figures have spurred the AFL into action. The league has teamed up with the Women's Health in Sport and Exercise team at La Trobe University to design the AFL's ACL injury reduction program called Prep to Play.

The team, led by Professor Kay Crossley, includes PhD candidate and AFLW player Brooke Patterson, Dr Alex Donaldson, Dr Andrea Bruder, Dr Andrea Mosler and Ms Haberfield.

Ms Haberfield explained that Prep to Play distinguishes between "modifiable" and "non-modifiable" factors that contribute to women's greater susceptibility for ACL injuries.

The non-modifiable factors include ones often featured in the media: being female, hormonal factors (although Ms Haberfield says more research is required), a family history and previous ACL injuries.

Modifiable factors by contrast include movement patterns, training load, muscle function, body mass index and — with some evidence from men's AFL and women's soccer in the US and Europe — footwear and ground conditions.

Prep to Play targets these factors. This week, for example, a new program targeted at community clubs (with educational videos) has been launched to help design the programs to help women avoid serious knee injury.

Sorry, this video has expired Why so many young women are getting sports injuries? ( Lauren Day )

Part-time leagues can cause injuries

Ms Haberfield acknowledged, however, that the semi-professional environment of AFLW presented challenges when it came to both prevention and recovery. For example, research indicates that if players engaged in an ACL reduction program exercises three times per week they could halve their risk of injury.

But with players' contracts ending immediately after the season, it left individual athletes to commit to their own exercise program alongside the need to making a living outside of sport.

Moreover, Ms Haberfield pointed out that those who did injure themselves faced a long and hard journey to recovery.

"My heart breaks every time I see one of the girls rupture their ACL. When you do an ACL in a semi-elite environment, it's a really lonely journey. It is OK when you're in season, training three times a week, but for players like Izzy Huntington and Nina Morrison [who ruptured her ACL in week two of the 2019 season], they have to attend rehab outside of the AFLW season on their own."

Dr Kate O'Halloran is host of Kick Like a Girl on AFLW radio and writes a weekly column on AFLW for the ABC.