Nalgas

Nalgas is the Spanish term for buttocks, the pair of rounded masses at the posterior aspect of the pelvis. In medical contexts, the region is referred to as the gluteal region and the muscles and tissues there as glúteos. The word nalgas is commonly used in everyday speech, while glúteos is the formal anatomical term.

Anatomy in this region includes skin, subcutaneous fat, and three main muscles: gluteus maximus, gluteus medius, and gluteus minimus. The gluteus maximus is the largest muscle and contributes to hip extension and outward rotation. The medius and minimus lie deeper and are involved in hip abduction and stabilization of the pelvis during locomotion. The gluteal region is supplied by the superior and inferior gluteal nerves and arteries, and contains surrounding connective tissue, fat, and fascia.

Functionally, the buttocks support body weight during standing and sitting, aid in movements such as climbing and rising from a seated position, and play a key role in stabilizing the pelvis and controlling leg movements during walking and running. They also cushion the lower back and transfer power between the upper and lower body.

Clinical notes: common issues include muscle strains or contusions from trauma or overuse, and conditions such as piriformis syndrome where surrounding structures irritate nearby nerves. The buttocks are also sites for intramuscular injections; the ventrogluteal region is often preferred today due to a lower risk to the sciatic nerve compared with the traditional dorsogluteal site.