It is slightly arched, so as to be convex in front, and concave behind, where it is strengthened by a prominent longitudinal ridge, the linea aspera.
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.
The lateral ridge termed the gluteal tuberosity is very rough, and runs almost vertically upward to the base of the greater trochanter.
Between the vastus lateralis and the adductor magnus two muscles are attached: the gluteus maximus inserted above, and the short head of the biceps femoris arising below.
This article incorporates text in the public domain from page 243 of the 20th edition of Gray's Anatomy (1918)