In connection with the vertical position of the body, such mechanical forces as body weight, viscera, intra-abdominal pressure, traction of muscles, tendons and ligament apparatus act on the human pelvis. The bone structures - the internal plates of the spongy substance and the end plates of the compact substance, the highest concentration of which occurs at the sites of compression and tension - are modeled under the influence of these forces. The aforementioned places of increased bone density in the composition of the bone pelvis are its buttresses. The connecting foundation of the buttress system of the pelvis is the sacrum, perceiving the effects of mechanical forces and transmitting them to the pelvic bones. The authors distinguished the following bone buttresses: 1 - lumbo-sacral-iliac-femoral; 2 - lumbo-sacral-iliac-sciatic; 3 - sacro-sciatic; 4 - sacro-femoral; 5 - sacro-iliac-pubical. It is necessary to consider buttresses of the pelvis from the position of arched structures, with the obligatory interaction of the contralateral sides. Arched structures formed by the lumbo-sacral-iliac-femoral, sacro-femoral and sacro-iliac-pubic buttresses function when the body is in vertical position, and the lumbo-sacral-iliac-sciatic and sacroiliac buttresses when the body is in seated position. Skeletal muscles attached to the bones of the pelvis also play an important role in the formation and maintenance of bone buttresses. They not only change its bone structure, but during their contraction also transmit tension to other bones, forming muscle buttress systems. In the work, the presence of the following musculoskeletal buttresses is proved: 1 - the external and internal ileo-femoral; 2 - external and internal obturator-femoral; 3 - pubic-sciaticfemoral-tibial; 4 - sciatic-tibial-fibular buttresses. It is shown that the pelvis is the most important part of the human musculoskeletal system and the stabilization ring for the free lower limb.