Anterior cruciate ligamentFunctional anatomy of the anterior cruciate ligament: The knee joint is a complex organ that allows multidirectional movement of the joint including internal/external rotation, flexion/extension and a variety of valgus movements. The direction of movement of the knee joint is regularly controlled by ligaments and geometric constraints of the joint surfaces (Woo et al., 1999). Knee movements can occur in different directions, giving each ligament a multifunctional purpose. The primary function of the anterior cruciate ligament is to prevent extreme movements of the anterior tibia at varying degrees of flexion. The ligament itself contributes significantly to the stabilization and kinematics of the knee joint. Additionally, the ACL functions as a major secondary constraint to internal rotation, particularly when the knee is near full extension. (Duthon et al., 2006)Origin/Insertion: The ACL is a large ligament connecting the anterior tibial plateau to the posterior femoral intercondylar notch. The tibial attachment is made on one facet, anterior and lateral to the anterior tibial spine. The femoral attachment is high on the posterior aspect of the lateral wall of the intercondylar notch. The ACL originates at the medial wall of the lateral femoral condyle and inserts in the middle of the intercondylar area. (Heming, Rand & Steiner, 2007))NORMAL: extension to flexionMale: normal ROM (6->140 degrees)Female: normal ROM (5->145 degrees)Anterior cruciate ligament tear: an injury to the anterior cruciate ligament ( ACL) is a devastating injury that occurs very commonly during sports participation. It is estimated that more than 200,000 ACL injuries occur each year in the United States.1-3...... middle of paper ......ptions, the knee cannot completely return to "normal" . However, surgical reconstruction is an attempt to make it as close as possible to the normal or capacity of the knee before the injury. Anterior Cruciate Ligament Rehabilitation Anterior cruciate ligament rehabilitation has undergone many changes over the past decade. Extensive research into the biomechanics of the injury itself and the operated knee have both contributed to a move away from the techniques of the early 1980s. The main goals of rehabilitation after ACL surgery are: 1) Restoration of joint anatomy; 2) Ensure static and dynamic stability; 3) Maintain aerobic conditioning and psychological well-being; These helped develop an intensive rehabilitation program for the patient. Active patient involvement will be required to ensure optimal recovery..