‘This isn’t a test of how hard you are’

DR Éanna Falvey of the Sports Surgery Clinic, Ireland rugby team doctor, define your terms: what is a cruciate ligament injury?

“When you put your foot on the ground and you twist or sidestep, that’s when you use your cruciate, to prevent excessive movement in your knee — anteroposterior, front to back movement, or rotational movement.

“The cruciate is made up of a number of bundles, and two functional bundles control front to back movement and rotation. When you tear it, in a small percentage of cases the damage is just to the anteroposterior bundle and there’s no rotational instability.