How Weakness of the Tensor Fascia Lata and Gluteus Maximus May Contribute to ACL Injury: A New Theory

Anterior cruciate ligament (ACL) injuries are common in sports including a significant failure rate following reconstruction. The iliotibial band (ITB) is an important stabilizer of the lateral portion of the knee and also an important lateral rotator of the tibia. Both the tensor fascia lata (TFL) and gluteus maximus (Gmax) muscles insert into the ITB proximally. This paper describes a theory that implicates weakened TFL and Gmax muscles as possible contributors to anterolateral rotatory instability. If the TFL and Gmax are important contributors to anterolateral rotatory instability, physical therapists can emphasize assessing for their weakness and developing a rehabilitation program to restore their strength.