Clinician Education: Non-contact ACL tears in females

Much has been made of female being more prone to non-contact tears of the anterior cruciate ligament (ACL) of the knee. These tears, often taking 9 months or more to fully rehabilitate to be able to return to pre-injury activities, has been attributed to a myriad of causes:
larger Q-angles because of the wider female pelvis
weakness of the gluteus medius muscle
hormonal fluctuations due to the menstrual cycle

However, females may be taught from an early age to tear their ACLs. From early childhood, females are taught to cross their legs when they sit. In the lady-like crossing, the hips are adducted and internally rotated leading to connective tissue shortening of the muscles that create this action and connective tissue lengthening of the muscles that prevent adduction and internal rotation.
When these females are asked to perform the NeuroFascial Patterns of a high step march/Trendelenburg test, the non-weight bearing leg will move into the position it has been conditioned to take: hip adduction and internal rotation.
When these same females squat, the hips again adduct and internally rotate. With the leg in a closed-chain pattern during squats, it produces a valgus force and tibial external rotation that increase the risk of injury to the MCL and ACL respectively.
Patient education may be a valuable intervention in these cases by instructing the female patient on proper sitting postures.