The inguinal ligament is a band of fibrous connective tissue found in the anterior pelvis. It runs from the upper outer aspect of the pelvis to the pubic bone. Its path can be traced along the diagonal crease on the front of the hip where the leg meets the torso. The function of the inguinal ligament is to hold in place several of the tissues of the pelvis as they cross into the front of the leg, including muscles, nerves, and blood vessels.
This ligament arises from the anterior superior iliac spine, which is the forward-facing border on the top of the iliac bone, the butterfly-wing-shaped bone of the pelvis. It is the bony crest that can be felt on the front of the hip. The inguinal ligament originates at the very top of the inguinal crease — the line where the leg meets the hip — along the front edge of this crest where the bone begins to curve downward.
From here, the ligament extends inward and downward in a straight line toward the pubic bone, which is the bottom inside bone of the pelvis. Like a rubber band stretched between these two bones, it attaches to a structure known as the pubic tubercle. The pubic tubercle is a bony eminence on the upper inner portion of the pubic bone. It is situated at the lower border of the inguinal crease.
As the dividing line between the torso and legs, the inguinal ligament serves as the lower border of the abdominal wall. A layer of tendon-like tissue known as an aponeurosis connects the bottom of the rectus abdominus or “six-pack” muscle and the external oblique muscle to the pelvis.
Along its inferior or lower border, the inguinal ligament is considered to be continuous with another fibrous layer known as the fascia lata. The fascia lata is a tendon-like envelope surrounding and separating the muscles of the thigh, its fibers running away from the ligament and down the leg. Also forming a border of the femoral triangle, a compartment of the anterior upper thigh, the inguinal ligament contains some important structures inside of the fascia lata and within the triangle. These include, within another layer known as the femoral sheath, the femoral nerve, the femoral artery and veins, and the inguinal lymph nodes.
