Linea aspera

Ridge on the posterior surface of the femur

Diagram of the femur showing the linea aspera.

The linea aspera is a prominent longitudinal ridge or crest on the posterior surface of the femur, the long bone of the thigh. It serves as an important site for muscle attachment and plays a crucial role in the biomechanics of the lower limb.

Anatomy

The linea aspera is located on the posterior aspect of the femur and runs vertically along the shaft of the bone. It is a roughened ridge that provides attachment points for several muscles and intermuscular septa. The linea aspera is divided into two distinct lips: the medial lip and the lateral lip.

Medial Lip

The medial lip of the linea aspera is the inner border of the ridge. It provides attachment for the vastus medialis muscle, which is part of the quadriceps femoris group. The medial lip also serves as an attachment point for the adductor longus and adductor magnus muscles, which are involved in the adduction of the thigh.

Lateral Lip

The lateral lip of the linea aspera is the outer border of the ridge. It provides attachment for the vastus lateralis muscle, another component of the quadriceps femoris group. Additionally, the lateral lip serves as an attachment for the gluteus maximus muscle, which is involved in the extension and lateral rotation of the thigh.

Intermediate Area

Between the medial and lateral lips, the intermediate area of the linea aspera provides attachment for the adductor brevis muscle. This area is also where the pectineus muscle attaches, contributing to the adduction and flexion of the thigh.

Function

The linea aspera is essential for the attachment of muscles that are involved in various movements of the hip and knee joints. The muscles attached to the linea aspera play significant roles in walking, running, and maintaining posture. The ridge also serves as a point of leverage for these muscles, enhancing their mechanical advantage.

Clinical Significance

Injuries or abnormalities involving the linea aspera can affect the function of the muscles attached to it, leading to difficulties in movement and stability of the lower limb. Fractures of the femur that involve the linea aspera may require surgical intervention to restore proper alignment and function.

Muscles of the thigh showing attachment to the linea aspera.

Related Structures

The linea aspera is continuous with the gluteal tuberosity proximally and the medial supracondylar ridge and lateral supracondylar ridge distally. These structures also serve as important sites for muscle attachment and are integral to the function of the lower limb.

Related Pages

• Femur
• Quadriceps femoris
• Adductor muscles of the hip
• Gluteus maximus