How to determine if i tore my acl?

Please see link...: "acl is the medical abbreviation for the anterior cruciate ligament. The acl is one of four major ligaments of the knee and stops the lower leg (tibia) from moving forward in relation to the thigh (femur) while providing rotational stability of the knee joint. Two bundles of fiber combine to make the acl..." http://www.Orthonc.Com/sites/default/files/forms/acl-db-web-page-rev-punched-redo.Pdf.

ACL: A pop at the time of injury followed by an inability to resume the activity and subsequent swelling, stiffness and pain are very common. Often a qualified orthopaedist will be able to confirm with physical examination. Finally, an MRI can be confirmatory and helpful to assess for other injuries.