Causes

The posterior cruciate ligament can tear if your shinbone is hit hard just below the knee or if you fall on a bent knee. These injuries are most common during:

• Motor vehicle accidents. A "dashboard injury" occurs when the driver's or passenger's bent knee slams against the dashboard, pushing in the shinbone just below the knee and causing the posterior cruciate ligament to tear.
• Contact sports. Athletes in sports such as football and soccer can tear their posterior cruciate ligament when they fall on a bent knee with their foot pointed down. The shinbone hits the ground first and it moves backward. Being tackled when your knee is bent also can cause this injury.