Trudi Lines calls it “random”, but her decision to move from Sydney to Townsville last year set in motion a chain of events that transformed her life.

“I actually was quite lost when I moved up here, I was just floating along,” says the Air Force veteran who has been diagnosed with Post Traumatic Stress Disorder (PTSD).

Feeling “lower than a pregnant ant” one day, Lines resisted her typical impulse to “hide away”, turning instead to Mates4Mates, an organisation that supports injured or ill current and ex-serving Australian Defence Force (ADF) personnel.

“I slowly started going to exercise classes there and then one of the ladies said, ‘You should apply for the Invictus Games,’ and I said, ‘Oh, I don’t think I [qualify]. I’ve just got a few injuries.’”

In fact, Lines had fallen for the common misconception that the Invictus Games – an adaptive multisport event for sick or injured armed services personnel launched in 2014 by Prince Harry – was only for the physically maimed.

Set straight, and encouraged by, the Mates4Mates employee, Lines applied and was successful.

“To get that call where they say, ‘Yep, you’ve made the team’, was pretty amazing,” says Lines, 40, who’ll represent Australia in wheelchair rugby and tennis at the Invictus Games in Sydney from October 20-27.

“I hope, fingers crossed, that [the Games] being on home soil in Australia helps to make people more aware of the mental-health issues that some people have that are kind of invisible, it’s well hidden,” says Lines, who appeared in the ABC-TV documentary Fighting Spirit: The Wheeling Diggers’ Invictus Games Dream on October 16 (available on iView).

An electrician who worked in logistics and air movements on humanitarian and peacekeeping operations, Lines was deployed in 2008 to Afghanistan, where she came under enemy fire while unloading a plane.

Two years later, she was again deployed to Afghanistan, and in 2017 Lines, who also has service-related injuries to her neck, back and ankle, was medically discharged after the PTSD diagnosis, and struggled to adjust to life outside the military.

“It’s made me realise how important sport is, how much it actually helps everything, including mental health.”

“There are so many different ways it affects people,” says Lines of PTSD.

“Mine was a huge anger issue, not so much now, but I was an angry little person,” says the 153cm competitor, who calls her pet Staffordshire terriers Angel, 12, and Diesel, 10, her “biggest support”.

Today, she’s improved through treatment including counselling, medication and equine therapy.

“I’m definitely a lot more aware of it now and I know if it’s building up I need to find ways to channel that,” she says.

“But I also now understand you need a balance, so I also have meditation, and my happy place is the beach.

“You’ve got to have that outlet where you get rid of the adrenalin but then have that quiet time, which is really important as well.”

Her experience with Invictus has made all the difference, too.

“It’s made me realise how important sport is, how much it actually helps everything, including mental health.”

Lines, who grew up in Shepparton in Victoria playing backyard cricket with her elder brother, Paul, now counts 10 other “brothers” in her Wheelchair Diggers teammates.

“They’re very funny and there’s a lot of banter going on,” says the former AFL player whose only previous experience of wheelchair sports was “a two-minute muck-around” in one after cheering on a match of wheelchair AFL.

“It has just opened my mind to these guys who live in a wheelchair. I just think they’re absolutely amazing.”

Now she’s passionate about spreading a message of hope through competing in the Invictus Games.

“I used to try and hide my PTSD. Now it’s out there, and that’s what it’s all about. If we can help one person who’s struggling, that’s job done,” Lines says.

“I can’t wait to put that green-and-gold top on and wheel out and have a go.”