[clairity]

it does provide rotational stability (along with the PCL, between the femur and tibia; the condyles help here too) but it’s primarily job is lateral stability in the front-to-back direction, because without that, you cannot negotiate uneven terrain at all. this is vividly illustrated in a dissection by manipulating the knee with and without cutting the ACL. with no ACL, the knee is a wobbly mess, especially in the front to back (ventral-dorsal) direction.

ACL injuries have long been known to be worse in women because of anatomical differences in weight distribution relative to hip to femur to tibia angles, both statically but especially in motion.