Bones of lower limb
Last reviewed: 23.04.2024
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The skeleton of the lower limbs consists of their belt and free parts of the lower limbs.
Belt of lower extremities (cingullum membri inferiores) is formed by two pelvic bones, which at the rear are almost immovably connected with the sacrum, and in front - with each other. The skeleton of the free part of the lower extremity (skeleton membri inferioris liberi) is distinguished by the proximal part - the femur, the middle section - the bones and fibula (two bones of the shin) and the distal part - the bones of the foot. In the region of the knee joint, there is a large sesamoid bone, the patella. In the distal part, in turn, three parts are distinguished: the tarsal bones, the bones of the metatarsus and the phalanges of the fingers.
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Bones of the lower extremity belt
Pelvic bone (os coxae) up to 12-16 years old consists of three separate bones connected by cartilage: iliac, pubic and sciatic, which at this age are intergrown with each other.
The iliac bone (os ilium) consists of two sections. The lower thickened section - the body of the ilium (corpus ossis ilii) - participates in the formation of the acetabulum. Upper, dilated section is the wing of the ilium (ala ossis ilii). It is a wide curved plate, thinned in the center. At the periphery, the wing is thickened, fan-shaped, and ends with the iliac crista (crista iliaca).
The pubic bone (os pubis) has an enlarged part - the body, and two branches. The body of the pubic bone (corpus ossis pubis) forms the anterior section of the acetabulum. From the front comes the upper branch of the pubic bone (ramussuperior ossis pubis) with the ilium-pubic elevation (eminentia iliopubica), located along the fusion of the pubic bone with the iliac.
The ischium bone (os ischii) has a thickened body (corpus ossis ischii), which completes the acetabulum from below and moves to the ischium (ramus ossis ischu) branch anteriorly.
Skeleton of a free part of the lower limb
Femur (femur) - the longest tubular bone in the human body. It has a body and two ends. On the upper (proximal) end is the head of the femur (caput femoris) for connection to the pelvic bone.
Shin bones
The lower leg has two bones. The tibia is medially located, laterally - the fibula. Each bone has a body and two ends. The ends of the bones are thickened and bear the surfaces for the connection with the femur at the top (tibia) and with the bones of the foot underneath. Between the bones is the interosseous space of the shank (spatium interosseum cruris).
Tibial bone (tibia) is the thickest bone of the shin. The proximal end of the bone is thickened and forms the medial and lateral condyles (condylus medialis and condylus lateralis). The upper articular surface (facies articularis superior) is upward and articulates with the femoral condyles.
The fibula is thin, with the head of the fibula (caput fibulae) on its upper, thickened (proximal) end. On the medial side of the head is the articular surface of the head of the fibula (facies articularis cdpitas fibulae) for articulation with the tibia.
The foot (pes) is divided into 3 departments: tarsus, metatarsus and fingers. The skeleton of these departments is the tarsi bones (ossa tarsi), the bones of the metatarsalia (ossa metasarsalia) and the bones of the toes (ossa digitorum pedis).
Tarsus bones
The tarsus consists of seven spongy bones arranged in two rows. The proximal (posterior) row consists of two large bones: the ram and the heel. The remaining five tarsal bones form a distal (anterior) row.
Plusset bones (ossa metatarsi). They include five tubular short bones. The shortest and thickest I metatarsal bone, the longest - II. Each bone has a body (corpus), a caput and a base. The bodies of the metatarsal bones have a convexity, turned in the back side. The bases are provided with articular surfaces for articulation with tarsal bones.
The toes of the foot, like the fingers of the hand, have a proximal phalanx (phalanx proximalis), an average phalanx (phalanx media) and a distal phalanx (phalanx distalis).