1 doctor weighed in:

Can you tear your ACL on purpose?

1 doctor weighed in

In brief: Psychiatrist

Hurting yourself intentionally seems a bit ridiculous to me.
But if I take your question seriously, a person must be pretty intelligent and athletic to control the body to injury something as specific as the ACL, or any other specific ligament/tendon/body part. You must know the exact anatomic motion and the exact way to injure such a specific body part. There are psychiatric disorders involved

In brief: Psychiatrist

Hurting yourself intentionally seems a bit ridiculous to me.
But if I take your question seriously, a person must be pretty intelligent and athletic to control the body to injury something as specific as the ACL, or any other specific ligament/tendon/body part. You must know the exact anatomic motion and the exact way to injure such a specific body part. There are psychiatric disorders involved
Thank