The linea aspera is a prominent longitudinal ridge or crest, on the middle third of the bone, presenting a medial and a lateral lip, and a narrow rough, intermediate line.

It is an important insertion point for the adductors and the lateral and medial intermuscular septa that divides the thigh into three compartments.

The tension generated by muscle attached to the bones is responsible for the formation of the ridges.

The tension generated by muscle attached to the bones is responsible for the formation of the ridges.

[1] This article incorporates text in the public domain from page 246 of the 20th edition of Gray's Anatomy (1918)