Which muscle forms most of the fleshy part of the buttock?

The gluteus maximus is the largest muscle in the human body, making up the majority of the fleshy part of the buttock. Its size and location are important for various functions such as movement of the hip and thigh, providing strength and stability during activities like walking, running, and climbing. The gluteus maximus plays a critical role in maintaining upright posture and supporting the pelvis during these movements. This muscle is not only vital for locomotion but also contributes to the overall shape and contour of the buttocks, making it significant in terms of both anatomy and physical appearance.

In contrast, while the gluteus medius and the tensor fasciae latae also contribute to the structure of the hip region, they are smaller and located more underneath or laterally, rather than forming the bulk of the buttock. The quadratus lumborum is primarily involved in stabilizing the lower back and has little to do with the fleshy aspect of the buttock. Thus, the gluteus maximus is clearly the critical muscle being referenced in relation to the fleshy part of the buttock.