A trochanter is a large, bony bump on your femur (thighbone) that serves as an anchor point for the muscles controlling your hip and leg. You have two main trochanters on each femur: the greater trochanter on the outer side of your hip and the lesser trochanter on the inner side, closer to your groin. These aren’t just bumps for the sake of it. They act as levers, giving your muscles the mechanical advantage they need to move your leg in almost every direction.
Greater Trochanter: The Bump You Can Feel
The greater trochanter is the wider, more prominent of the two. It sits on the outer (lateral) side of your upper thigh, and you can actually feel it by pressing into the side of your hip while standing. That bony ridge just below your hip joint is the top of the greater trochanter.
This structure is the attachment site for several powerful muscles that control hip movement. The gluteus medius, one of the main muscles responsible for keeping your pelvis level when you walk, wraps around its posterior tip and extends along its lateral and anterior surfaces. The gluteus minimus attaches to the front of the trochanter. The piriformis, a deep rotator muscle that runs from your sacrum (the triangular bone at the base of your spine), inserts along its upper border. The vastus lateralis, the large muscle on the outside of your thigh that helps straighten your knee, originates here as well.
The position of the greater trochanter matters more than you might expect. Biomechanical modeling has shown that when the greater trochanter sits slightly more lateral (farther from the body’s midline), the force on the hip joint drops considerably and the hip abductor muscles work more efficiently. A trochanter that shifts inward or upward does the opposite, increasing joint stress and weakening the mechanical advantage of those muscles. This is why surgeons pay close attention to trochanter positioning during hip replacement surgery.
Lesser Trochanter: The Hidden Anchor
The lesser trochanter is smaller and sits on the inner, lower portion of the femur’s upper end. You can’t feel it through the skin because it’s buried beneath layers of muscle. Its primary job is anchoring the iliopsoas, the body’s most powerful hip flexor. This muscle is actually two muscles working together: the psoas major, which runs from the lower spine, and the iliacus, which lines the inside of the pelvis. In about 70% of people, these two muscles have separate attachment points on the lesser trochanter, with the iliacus sitting slightly more forward and the psoas on the tip. In the remaining 30%, they merge into a single tendon before attaching.
The iliopsoas does more than flex your hip. It helps stabilize your lower spine and pelvis during movements like walking, running, or even just standing on one leg. The lesser trochanter is also an important vascular landmark: the femoral artery, which supplies blood to your leg, splits into its deep and superficial branches right at this level.
The Third Trochanter
Some people have an additional bony prominence called the third trochanter, located along the upper shaft of the femur below and behind the greater trochanter. Depending on how strictly researchers define it, the third trochanter appears in anywhere from 6% to as many as 72% of human femurs. A study of 622 femora from archaeological sites found a rate of about 6%. Rather than being a sign of skeletal evolution, this variation appears to be linked to altered gluteal muscle function, essentially a response to how forces are distributed along the bone during a person’s lifetime.
Greater Trochanteric Pain Syndrome
The most common clinical problem involving a trochanter is greater trochanteric pain syndrome (GTPS), which causes pain and tenderness on the outer side of the hip. Prevalence is notably higher in women: about 15% of women experience it on one side and 8.5% on both sides, compared to roughly 7% and 2% of men, respectively.
The pain typically comes from inflammation of the trochanteric bursa, a fluid-filled cushion that sits between the greater trochanter and the iliotibial band (the thick strip of connective tissue running down the outside of your thigh). This bursa normally reduces friction as tendons and muscles glide over the bone, but when it becomes irritated, the result is aching or sharp pain across the lateral thigh and buttock. Many people also feel it radiating down the leg or into the lower back.
Daily activities tend to make it worse. Climbing stairs, sitting for long stretches, sleeping on the affected side, and high-impact exercise are common triggers. The pain can last weeks, months, or even years if left unaddressed. On MRI, patients with this syndrome almost always show abnormal fluid around the trochanter and are significantly more likely to have damage to the gluteal tendons. Interestingly, though, many people without any hip pain also show similar fluid on imaging, so MRI findings alone don’t confirm the diagnosis. A physical exam, specifically tenderness when pressure is applied to the greater trochanter while lying on your side, remains the most reliable way to identify it.
Trochanteric Fractures
Because the trochanters sit at the junction between the femoral neck and the shaft, this region is vulnerable to fractures, particularly in older adults with weakened bones. Hip fractures in this area fall into two main categories. Intertrochanteric fractures occur between the femoral neck and the lesser trochanter, running through the bone that connects the two trochanters. Subtrochanteric fractures happen just below the lesser trochanter, in the upper shaft of the femur. Both are classified as extracapsular fractures, meaning they occur outside the hip joint capsule itself, which distinguishes them from femoral neck fractures that happen higher up, within the capsule.
The distinction matters for treatment and recovery. Extracapsular fractures generally have a better blood supply to the broken bone, which influences healing and the type of surgical repair used. Intertrochanteric fractures are among the most common hip fractures in older adults and typically result from falls, though they can also occur from lower-energy injuries in people with significant bone loss.