Nobody touched me, so how did I tear my ACL?

The typical moment of injury

Patients often describe it the same way: they went to change direction, stopped quickly to receive a ball, or landed awkwardly, and the knee seemed to go one way while the body went the other. Many hear or feel a pop and have to stop playing. Swelling often appears within a few hours because the torn ligament bleeds into the joint.

Movements that load the ACL most

• Cutting or side-stepping with the foot planted
• Decelerating sharply, for example to stop at the padel wall or the edge of the box
• Landing from a jump with the knee straight or falling inwards
• Pivoting on one leg while the shoe stays fixed to the ground
• A direct blow to the outside of the knee, as in a tackle, which is the less common contact mechanism

Why some people are more at risk

Risk factors include previous ACL injury, fatigue late in a game, weak hip and hamstring muscles, landing with the knees falling inwards, high-grip artificial turf or court shoes, and female sex. Anatomy matters too: the shape and slope of the top of the shin bone and the size of the notch the ACL sits in vary between people. Several of these can be improved with training; some cannot.

After a non-contact twist

Stop playing, use ice, elevation and crutches if walking hurts, and avoid testing the knee. If it swelled quickly, felt unstable or you heard a pop, book an examination. Dr. Gelber sees these injuries regularly at Aman Hospital and can tell you whether the ACL, meniscus or another structure is involved.