Linea aspera

Linea aspera, located on the posterior border of the femur’s body or shaft, is a rough bony ridge. It serves as an attachment site for intermuscular septa and various muscles. The adductor magnus, the largest adductor muscle, inserts directly onto the linea aspera and its extensions above and below. The linea aspera features prominent medial and lateral lips, which offer origin to the vastus medialis and vastus lateralis muscles, respectively. Other muscles originating from the linea aspera include: 1) the short head of biceps femoris muscle, located between the attachments of adductor magnus and vastus lateralis muscles, and 2)-the adductor longus and adductor brevis muscles, situated between the attachments of adductor magnus and vastus medialis muscles.

Moving upwards, the linea aspera continues medially–towards the lesser trochanter–as the spiral line (a.k.a. pectineal line), which provides attachment for the pectineus muscle. On the lateral side, the linea aspera extends as the roughened gluteal tuberosity towards the greater trochanter of the femur, where it attaches to the gluteus maximus muscle.

Towards the lower end, the linea aspera diverges into the medial and lateral supracondylar lines, which terminate at the medial and lateral condyles of the femur. Between these lines lies the posterior popliteal surface. The lateral supracondylar line serves as the origin site for the plantaris and lateral head of the gastrocnemius. The popliteal surface (i.e., the floor of popliteal fossa), provides attachment for the medial head of the gastrocnemius muscle. The summit of the medial supracondylar line on the medial condyle is called the adductor tubercle, which attaches to the lowermost part of the adductor magnus muscle.