ACL rupture
ACL rupture is rarer and more severe than tennis elbow and happens when the ligament crosses the centre of the knee and helps to stabilise the joint.
Professor Lee said: “This usually happens during cutting, change of direction and sudden stopping and starting, typically during the late stages of the game, when your thigh muscles become tired.
“If it is torn, the shin bone slides forward, often with a popping sound, causing pain and swelling. Bracing and physiotherapy are useful in some types of injury, but if it is completely torn, treatment usually involves surgery.
“X rays usually are normal, MRI scans are the first protocol to diagnose the injury. Knee injury is common in tennis, if managed well, like Roger Federer and Tim Henman, players can return to the top of their game.”