Maximizing Your Gluteus Maximus: The Powerhouse Behind Every Step!
Everyone is familiar with the gluteus maximus. It’s your butt muscle, the one you’re probably sitting on right now. But as with so many aspects of our anatomy, this familiar muscle is much more complex than we often think. In this article, we’ll take a look at the different parts of this important muscle, learn where they attach, and explore how we use this muscle in movement.
Muscle attachments
Typically the gluteus maximus is the largest muscle in the body, so it has a broad area of attachments. Some anatomists divide the muscle into superior (upper) and inferior (lower) fibers because attachment locations and fiber direction impact which actions certain areas of the muscle can contribute to. All portions of this muscle are superficial. Muscles that are deep to (underneath) the gluteus maximus include the deep six lateral rotators, gluteus minimus, and most of the gluteus medius.
The attachments considered the origin of this muscle span an area from the iliac crest all the way to the coccyx. On the superior end of this muscle, those attachments start around the posterior iliac crest, although some superior fibers may also merge with the thoracolumbar fascia. Gluteus maximus fibers then attach all along the lateral side of the sacrum and coccyx, and finally, some fibers merge with the sacrotuberous ligament.
From their point of origin, the fibers of gluteus maximus run in a slightly oblique direction. They attach at two main points that are considered the insertion for this muscle. The more superior fibers insert onto the gluteal tuberosity, a rough bony ridge on the posterior femur just below the greater trochanter. The more inferior fibers insert into the iliotibial band (IT band).
Muscle actions
The primary action of gluteus maximus is hip extension. It’s a large muscle, so it can contribute lots of power to the action of hip extension when that’s needed. Additionally, all fibers of gluteus maximus can contribute to lateral rotation and abduction of the thigh at the hip. Because of where they attach, the inferior fibers can also assist with adduction of the thigh at the hip.
Finally, it’s important to remember that the action of a muscle can change if we fix what is often considered the more moveable bone where that muscle is attached. In the case of gluteus maximus, if we’re standing on the leg, so the thigh is held in place, then this muscle can contribute to posteriorly rotating the pelvis on the thigh.
Providing power
One of the key roles of the gluteus maximus muscle is supplying power. In functional movement, this muscle is an important part of powering through activities like running, walking up stairs, or hiking uphill. In situations like running or hill climbing, our other hip extensors, our hamstrings, are less powerful. This is because the hamstrings cross the knee joint in addition to the hip joint, and in running or hill climbing, the knee is bent. So in these situations, gluteus maximus provides a lot of our power for dynamic hip extension.
Supporting balance
Gluteus maximus is engaged at a much lower level in less intense activities like regular walking or standing. However, through its attachment into the thoracolumbar fascia which then merges with the contralateral latissimus dorsi, the action of gluteus maximus can affect the balance of cross-body tension that affects our gait. This is because in gait, the contralateral arm swings forward when the opposite leg steps forward.
Keeping us upright
Finally, gluteus maximus is also part of helping us move into an upright position. Posturally, we use gluteus maximus in sitting to help us stay upright. Its action as a hip extensor helps balance out the activity of the hip flexors on the opposite side of our pelvis. In functional movement, we also use this muscle when we move to a standing position from a seated or a bent-over position.
Conclusion
The gluteus maximus is a large superficial muscle with broad attachments. It’s active to some degree in walking and standing. However, its primary role is to provide powerful hip extension when we need it to climb stairs, hike uphill, or run. It also supports us posturally when sitting and transitioning from a seated into a standing position.