Picture showing the oblique, wide and strong anterior cruciate Ligament.

This is looking from the front, with the knee cap removed.

When it tears is stetches first, absorbs alot of energy. When it finally ruptures the energy is released a pop or snap sound is often heard.

The ACL acts as a checkrein preventing the upper bone (femur) slipping off the back of the lower bone. Small degrees of this cause the knee to give way unpredictably.

Without an Anterior Cruciate Ligament the knee will often:

Give Way

Will not allow turning - because the 2 bones are not properly connected, when a patient twists the lower bone won't follow round with the upper bone.

The knee will feel unstable

There will be a lack of trust in the knee.

You will be able to run in a straight line and cycle without difficulty.