The buttocks (from the Latin fissa, “cleft, fissure”), also called the gluteal region, designate the region located behind the body which is both rounded and protruding.

The buttocks are located behind the hip, between the trunk and the root of the lower limbs. They are separated by the inter-gluteal fold which ends at the bottom of the anus. The buttocks are made up mainly of the gluteal muscle which is made up of three layers:

• The gluteus maximus: in area, it is the largest and most powerful muscle in the body
• The gluteus medius: on the side, below the gluteus maximus,
• The gluteus minimus: deep and underdeveloped

These muscles connect the pelvis to the femur. They are involved in the balance and rotation of the pelvis and allow movement of the thighs and legs. They are also made up of fatty tissue.

The buttock is traversed by the sciatic nerve. It originates at the level of the sacral plexus, a set of nerves originating from the spinal cord at the level of the sacrum (located at the bottom of the spine just above the coccyx). It travels in the buttock then on the back side of the thigh to end behind the knee. It is the largest and longest nerve in the body: it alone provides motor skills and sensitivity to the lower limb.

The buttocks, physical characteristics of bipedalism

The transition to a standing position developed the muscles of the buttocks of bipeds and favored their plump appearance (2). Man is the mammal with the most developed gluteal muscle. In other animals, the rounded aspect of the buttocks does not appear because of the angle directly formed between the thighs and the back.

Sciatica : irritation of the sciatic nerve, it results in pain in the buttock, the thigh and can extend to the foot.

Cellulalgia : is characterized by pain in the buttock due to the presence, inside the muscles, of painful nodules which are located near the sciatic nerve. The symptoms are similar to those of sciatica.

tendonitis : inflammation of the tendons of the gluteal muscles. Mainly affects the gluteus medius. Characterized by pain in the buttock.

Boil (or folliculitis): it is the infection of the base of a hair due to a bacterium (in the majority of cases a staphylococcus aureus). Hairy areas subject to friction (beard, armpit, back and shoulders, buttocks, thighs) are the most exposed to boils.

Cellulite : result of a change in the structure of adipose tissue located under the skin. It gives the skin an appearance of small bumps called dimpling. Almost exclusively affecting women, it is mainly observed on the back of the thighs and on the buttocks.

Diaper rash (red buttocks) : it is an irritation of the skin of the buttocks of the baby which results in dry or oozing redness, with or without small buttons. It occurs as a result of friction with the diaper and maceration with urine and stool. This pathology is very common in infants, all the more so at the time of gaining a sitting position, between 6 and 12 months. The treatments are generally effective and prevent superinfection by the development of a fungus, the candida albicans.

Bedsores : skin lesions that result from repeated pressure on points of support such as the buttocks, elbows, heels or neck for example. Pressure ulcers mainly affect people in wheelchairs or those who are bedridden who cannot easily change their position. The skin gets compressed between the bed and the bones, which crushes the blood vessels deep down. Blood no longer circulates in these tissues which eventually die and become necrotic. When the first sign of a pressure sore appears on the surface, redness on the skin, it is already too late: the muscles and bones are already affected.

THEerythema diaper in infants is preventable by following simple actions such as frequently changing the baby in order to keep him dry, not putting on too tight clothes or even cleaning the buttocks properly without too aggressive products (6).

According to the Haute Autorité de Santé (HAS) (7), nearly 300 people are affected by bedsores each year. The importance of these skin lesions makes it essential to prevent them before it is too late. This prevention involves in particular massaging the areas at risk and the use of a cushion by the patients to modify the points of support or frequent changes of position. These practices limit the risk of developing a pressure sore. 

Medical consultation : In the event of damage to the gluteal muscles or the sciatic nerve or any other skin condition, it is necessary to consult a doctor.

Liposuction : aesthetic surgical technique, it consists in sucking subcutaneous fat using cannulas. Only a certain type of fat, such as those located in the hips, thighs and buttocks (also called saddlebags) can be removed.

The buttocks have always been the symbol of sensuality, beauty and fertility.

Whether in painting or sculpture, artistic representations are numerous. In Antiquity, artists sculpted statues of Venus that showcase the female buttocks (8). Later, European paintings are numerous to represent nudes. According to a XNUMXth century English doctor and psychologist, Havelock Ellis, corsets were even invented to highlight the buttocks of women under their dresses.

The buttocks of women are generally more rounded and protruding than those of men. The shapes also differ between individuals. In some populations of Africa, there is a genetic characteristic that gives women very prominent buttocks. This is called steatopygia: it is an enlargement of the fatty tissue of the buttocks which results in the exaggerated development of the buttocks (9,10).