Inner Thigh Mass
There are several muscles on the inside of the thigh, most of which lie under protective layers of fat and lack distinguishing breaks between them. Thus most artists, even when rendering a heroic figure, group them as one shape.
From the front, this shape is a triangle formed by the inner edge of the thigh, sartorius, and the lower border of external oblique (which is the inguinal ligament on the pelvis).
Its major form is adductor longus, which originates on the pubic bone and inserts on the posterior side of the femur. Upward and laterally lies pectineus (
peck-TIN-nee-us, from pecten, the pubic bone) and iliopsoas (
ill-ee-oh-SOH-ass), which makes a brief appearance in the upper corner of the triangle on its way from the spine to the femur. The artist will be hard-pressed to find these short divisions on the model.
The most distinct muscle of the adductor group is gracilis (
GRASS-ill-iss, akin to gracile, slender and graceful). Gracilis originates on the underside of the anterior part of the ischium. Its round belly lies on the upper two-thirds of the thigh. Below, it tapers into a skinny tendon that follows the bulk of sartorius into the medial condyle of the tibia.
Gracilis is the most medial adductor, and it can be seen in both front and back views of the thigh.
Adductor magnus, as its name suggests, is a large muscle, but only a small portion of it can be seen on the surface. It originates on the lateral surface of the ischium, posterior to gracilis, and inserts deeply to a long line on the back of the femur. Only the top portion is visible, as a wedge-shaped bulge between gracilis and the hamstring muscles.