Anterior Cruciate Ligament ruptures are every athlete's worse nightmare, especially netballers.
In New Zealand, 400 women rupture their ACLs annually, costing the tax payer $10.4 million - something recovered Northern Stars midcourter Holly Fowler knows all too well.
"As soon as it happened, I just knew my ACL went. I'd never had a big injury before. I was like it's gone, it's done, that's my season over for the year," Fowler said.
"Rehab was easily the most challenging thing I've ever had to go through, both physically and mentally."
But as former Silver Ferns physio Sharon Kearney explains, it's not just at an elite level.
"ACL's at an elite level are the tip of the iceberg, they're public. What we're really key and focusing on is what we call the silent ACL's, they're the ones that aren't on television."
Kearney regularly sees girls as young as 14 with ruptured ACL's.
"We know post puberty that girls land differently. When they come back to play sport post growth phase, they land, they don't bend their knees well, they don't control their limbs" she said.
Last November, Kearney took on the full time role of managing the Netball Smart Injury Prevention Programme.
Steel's Dani Gray is assisted after being injured during the ANZ Premiership netball match between the Pulse and Steel at the Te Rauparaha arena in Wellington.
She developed a dynamic warm up based on the FIFA 11 warm up, and is now used by players nationwide.
She's now seen a 13 per cent decrease in netball knee injuries and with another 6 development officers coming on board, Netball Smart hopes to reduce injuries even more.
"A key focus for us is getting into that intermediate school area so that we can actually teach the coaches to teach their kids how to jump and land well at that phase" Kearney said.
Sharon Kearney has been involved with the Netball New Zealand since 1993. She explains simply how ACL's are ruptured, and some strategies to prevent the injury from happening.
Story by 1 NEWS Sport producer Maddy Lloyd