The greater trochanter is a distinct bony projection located on the upper, outer side of the femur, or thigh bone. It is a significant landmark in the hip and thigh, often felt as a prominent point on the side of the upper leg. This structure is important for hip movement and stability, serving as an attachment point for several muscles that facilitate lower limb actions.
Understanding the Greater Trochanter’s Anatomy
The greater trochanter is a large, irregular, four-sided bony prominence found at the top of the femur, where the femoral neck meets the shaft. It extends upward, outward, and backward from the femur. This structure features a deep depression on its medial surface known as the trochanteric fossa and serves as an attachment site for numerous muscles and ligaments that contribute to hip joint function.
Several muscles insert onto different facets of the greater trochanter. The gluteus medius and gluteus minimus muscles attach to its lateral and anterior surfaces. Deep hip rotators such as the piriformis, obturator internus, superior gemellus, inferior gemellus, and obturator externus muscles also find their insertion points on the greater trochanter, particularly within the trochanteric fossa and surrounding areas. The strategic positioning and robust structure of the greater trochanter allow it to withstand significant forces from these powerful muscle groups.
Its Role in Movement
The greater trochanter serves as a mechanical lever arm, enhancing the efficiency and power of the muscles attached to it. These muscles work synergistically to produce various movements at the hip joint. For instance, the gluteus medius and gluteus minimus are primary abductors, moving the leg away from the midline of the body. They also contribute to the medial rotation of the thigh.
Beyond abduction, muscles inserting on the greater trochanter facilitate hip rotation, both internally and externally. This rotational capability is important for activities requiring twisting motions of the leg. These muscles also stabilize the pelvis during weight-bearing activities, such as walking, running, and standing on one leg. Their coordinated action helps maintain balance and ensure fluid, controlled movement of the lower limb.
Common Conditions Affecting the Greater Trochanter
The greater trochanter and the soft tissues surrounding it can be sources of pain. A common umbrella term for conditions causing lateral hip pain in this area is Greater Trochanteric Pain Syndrome (GTPS). GTPS often encompasses conditions such as trochanteric bursitis and gluteal tendinopathy. Trochanteric bursitis involves irritation or inflammation of the bursa, a fluid-filled sac that cushions the area between the greater trochanter and overlying muscles or tendons. Gluteal tendinopathy refers to issues with the tendons of the gluteal muscles, involving degeneration or irritation rather than outright inflammation.
Symptoms of these conditions commonly include pain on the outside of the hip, which can extend down the side of the thigh or into the buttock. This pain often worsens with specific activities, such as walking, climbing stairs, or getting up from a seated position. Individuals also experience increased pain when lying on the affected side at night or when applying direct pressure to the area.
Several factors can contribute to the development of GTPS. Repetitive motions, overuse from activities like running or cycling, and direct trauma such as a fall onto the hip are common triggers. Muscle imbalances or weakness in the hip and surrounding areas, postural issues, unequal leg length, and increased body weight can also place additional stress on the greater trochanter and its associated soft tissues. These conditions are frequently observed in middle-aged women.