The greater trochanter is a large, square-shaped bony prominence situated at the upper end of the femur, or thigh bone. This projection is a significant anatomical landmark that serves as a powerful anchor point for several muscles controlling the hip joint. Its location and structure are fundamental to the mechanics of walking, running, and maintaining upright posture. This article identifies the major muscle groups that insert on the greater trochanter and explains their importance for function and stability.
Identifying the Greater Trochanter
The greater trochanter is a prominent, palpable structure located on the lateral, or outer, side of the upper thigh, just below the waistline. It projects outward from the junction where the femoral neck connects to the shaft of the femur. This lateral placement significantly increases the mechanical advantage for the muscles that attach there.
The trochanter functions as a substantial lever arm, dictating the angle of pull and the power of the attached muscles. While a small muscle, the vastus lateralis, originates here, the greater trochanter is primarily an insertion site for the tendons of several powerful muscles originating from the pelvis. Its bony surface features four distinct facets—anterior, lateral, posterior, and superoposterior—that provide precise attachment points for different muscle tendons.
The Major Hip Abductor Attachments
The most significant muscles attaching to the greater trochanter are the primary hip abductors: the Gluteus Medius and the Gluteus Minimus. These muscles originate on the outer surface of the ilium, the large bone of the pelvis. Their main action is abduction, moving the thigh away from the midline of the body.
The Gluteus Medius is a thick, fan-shaped muscle that inserts on the superoposterior and lateral facets of the greater trochanter. This muscle stabilizes the pelvis during single-leg stance, such as walking, by preventing the opposite side of the pelvis from dropping. The Gluteus Minimus is the deepest and smallest of the gluteal muscles and inserts onto the anterior facet. Both muscles work together to maintain a level pelvis, which is fundamental for an efficient gait cycle.
The Deep Hip Rotator Attachments
A group of smaller, deeper muscles also converge on the greater trochanter, influencing hip rotation and joint stability. These are often collectively referred to as the deep external rotators, or the “Deep Six,” which all originate on the pelvis and insert onto the femur. This group includes the Piriformis, the Obturator Internus, and the Superior and Inferior Gemelli.
The Piriformis muscle is the most superior of this deep group, inserting onto the apex of the greater trochanter. The Obturator Internus, along with the Superior and Inferior Gemelli, often share a common tendon to insert into the medial surface, within the deep depression known as the trochanteric fossa. The main function of these deep muscles is to laterally rotate the thigh. They also pull the ball of the femur firmly into the hip socket, contributing significantly to overall joint stability.
Understanding Pain in the Trochanteric Region
The concentration of muscle and tendon attachments makes the greater trochanter region susceptible to specific pain conditions, often grouped under the umbrella term Greater Trochanteric Pain Syndrome (GTPS). Historically, the most common diagnosis was Trochanteric Bursitis, which involves inflammation of the bursa that lies over the lateral surface of the greater trochanter.
Recent research suggests that a more frequent cause of lateral hip pain is Gluteal Tendinopathy, which is a degeneration of the Gluteus Medius and Minimus tendons at their insertion points. This condition results from repetitive strain or compression, such as excessive walking or running. The associated bursitis is often considered a secondary finding to the underlying tendon issue. Pain typically presents as tenderness on the side of the hip, worsening with activity or when lying on the affected side at night.