The ACL (anterior cruciate ligament) is located inside the knee joint. It connects the thigh bone (femur) to the shin bone (tibia) and sits in the center of the knee.
Basic location
The ACL is one of the four main ligaments of the knee and lies deep within the joint, between the femur and tibia. It crosses in the middle of the knee with the posterior cruciate ligament (PCL), forming an “X” shape that helps control front‑to‑back and rotational motion.
More precise anatomy
The ACL originates from the inner part of the end of the femur (the medial surface of the lateral femoral condyle) and runs down to attach on the upper surface of the tibia in front of the intercondylar eminence. Functionally, this central position in the knee allows the ACL to prevent the tibia from sliding forward relative to the femur and to provide rotational stability during cutting and pivoting movements.