A sudden “pop” at the time of injury
Immediate swelling within a few hours
Severe knee pain right after the injury
Feeling like the knee is unstable or “gives out”
Trouble bearing weight or walking normally
Loss of full range of motion
Pain when trying to pivot, twist, or change direction
Tenderness around the knee joint
A feeling that the knee is loose or shifting
Bruising around the knee after the injury
Difficulty continuing the activity after the injury
Symptoms that do not improve over a few days
A medical exam is needed to confirm an ACL tear
An MRI is often used to diagnose it
Seek urgent care if the knee is very swollen, deformed, or you cannot walk