Tokyo Olympics 2020: Pole vaulter Eliza McCartney reveals cause of injury woes

Pole vault star Eliza McCartney has discovered the cause of a seemingly endless run of injuries since her surprise Olympic bronze medal at Rio three years ago.

The Aucklander has established herself as one of the top exponents of her craft in the world, also winning silver at last year's Gold Coast Commonwealth Games and threatening the five-metre barrier that only two women have ever cleared.

McCartney, 22, is ranked fourth all-time with her 4.94m result at Jockgrim, Germany, in July 2018.

But she has barely been able to stay on the track over recent years, plagued by Achilles tendon and hamstring injuries that cut short her 2019 world championship campaign in September.

On Thursday, McCartney revealed the affliction that has held her back.

"We think I might have a genetic disorder that cause autoimmune inflammation, particularly affecting tendons," she posted on Instagram.

"Essentially, this means, over time, micro-trauma causes my immune system to go into overdrive and set off an inflammatory process in the affected areas.

"I've been continually challenged by this year and, at times, it's been difficult to cope, but the good news is I've started medication for this condition and I'm finally feeling my positive self again."

After returning from Europe, McCartney was briefly able to train pain-free, but was soon sidelined, when her Achilles "completely deteriorated".

"Numerous scans, in and out of a moon boot, not able to walk, some days unable to even put any weight through that foot, and all the while being completely unclear on why I had such an atypical Achilles tendinitis."

While the affliction will likely keep McCartney out of action over the domestic summer season, she still hopes to recover in time to qualify for the Tokyo Olympics.

"It's going to be far from the ideal build-up to an Olympics, but after a year off, I'm bloody ready for the challenge." she posted.

McCartney encouraged her followers to asked questions about her condition.

"Thank you all for sticking with me through these tough times, and a big thank you to my team and everyone else, who has kept me afloat each time I've started to sink."