Calcaneus | |
---|---|
The calcaneus forms the bony part of the heel. It forms a joint with the talus bone, the subtalar joint. | |
![]() Bones of the foot, with the calcaneus shown in red | |
Details | |
Identifiers | |
Latin | Calcaneus, Calcaneum, Os calcis |
MeSH | D002111 |
TA98 | A02.5.11.001 |
TA2 | 1468 |
FMA | 24496 |
Anatomical terms of bone |
In humans and many other primates, the calcaneus ( /kælˈkeɪniəs/ ; from the Latin calcaneus or calcaneum, meaning heel [1] ) or heel bone is a bone of the tarsus of the foot which constitutes the heel. In some other animals, it is the point of the hock.
In humans, the calcaneus is the largest of the tarsal bones and the largest bone of the foot. Its long axis is pointed forwards and laterally. [2] The talus bone, calcaneus, and navicular bone are considered the proximal row of tarsal bones. [3] In the calcaneus, several important structures can be distinguished: [3]
There is a large calcaneal tuberosity located posteriorly on plantar surface with medial and lateral tubercles on its surface. Besides, there is another peroneal tubecle on its lateral surface. [2] On its lower edge on either side are its lateral and medial processes (serving as the origins of the abductor hallucis and abductor digiti minimi). The Achilles tendon is inserted into a roughened area on its superior side and the cuboid bone articulates with its anterior side.[ citation needed ] On its superior side there are three articular surfaces for the articulation with the talus bone. [2] Between these superior articulations and the equivalents on the talus is the tarsal sinus (a canal occupied by the interosseous talocalcaneal ligament).[ citation needed ] At the upper and forepart of the medial surface of the calcaneus, below the middle talar facet, there is a horizontal eminence, the talar shelf (also sustentaculum tali). [2] Sustentaculum tali gives attachment to the plantar calcaneonavicular (spring) ligament, tibiocalcaneal ligament, and medial talocalcaneal ligament. This eminence is concave above, and articulates with the middle calcaneal articular surface of the talus; below, it is grooved for the tendon of the flexor hallucis longus; its anterior margin gives attachment to the plantar calcaneonavicular ligament, and its medial margin to a part of the deltoid ligament of the ankle-joint.
On the lateral side is commonly a tubercle called the calcaneal tubercle (or trochlear process). This is a raised projection located between the tendons of the peroneus longus and brevis. It separates the two oblique grooves of the lateral surface of the calcaneus (for the tendons of the peroneal muscles).
Its chief anatomical significance is as a point of divergence of the previously common pathway shared by the distal tendons of peroneus longus and peroneus brevis en route to their distinct respective attachment sites. [3]
The calcaneus is part of two joints: the proximal intertarsal joint and the talocalcaneal joint. The point of the calcaneus is covered by the calcanean bursa.
In the calcaneus, an ossification center develops during the 4th–7th week of fetal development. [3]
Three muscles insert on the calcaneus: the gastrocnemius, soleus, and plantaris. These muscles are part of the posterior compartment of the leg and aid in walking, running and jumping. Their specific functions include plantarflexion of the foot, flexion of the knee, and steadying the leg on the ankle during standing. The calcaneus also serves as origin for several short muscles that run along the sole of the foot and control the toes.
![]() | ![]() |
Muscle | Direction | Attachment [4] |
---|---|---|
Gastrocnemius | Insertion | Calcaneal tubercle through the achilles tendon |
Soleus | Insertion | Calcaneal tubercle through the achilles tendon |
Plantaris | Insertion | Calcaneal tubercle either directly or through the achilles tendon |
Extensor digitorum brevis | Origin | Dorsal side of calcaneus |
Abductor hallucis | Origin | Medial process of calcaneus |
Extensor hallucis brevis | Origin | Dorsal side of calcaneus |
Abductor digiti minimi | Origin | Calcaneal tubercle |
Flexor digitorum brevis | Origin | Calcaneal tubercle |
Quadratus plantae | Origin | Lateral and medial processes of calcaneus |
Normally the tibia sits vertically above the calcaneus (pes rectus). If the calcaneal axis between these two bones is turned medially the foot is in an everted position (pes valgus), and if it is turned laterally the foot is in an inverted position (pes varus). [5]
The talar shelf is typically involved in subtalar or talocalcaneal tarsal coalition.
The foot is an anatomical structure found in many vertebrates. It is the terminal portion of a limb which bears weight and allows locomotion. In many animals with feet, the foot is a separate organ at the terminal part of the leg made up of one or more segments or bones, generally including claws or nails.
The human leg, in the general word sense, is the entire lower limb of the human body, including the foot, thigh and even the hip or gluteal region. However, the definition in human anatomy refers only to the section of the lower limb extending from the knee to the ankle, also known as the crus or, especially in non-technical use, the shank. Legs are used for standing, and all forms of locomotion including recreational such as dancing, and constitute a significant portion of a person's mass. Female legs generally have greater hip anteversion and tibiofemoral angles, but shorter femur and tibial lengths than those in males.
In human anatomy, the fibularis longus is a superficial muscle in the lateral compartment of the leg. It acts to tilt the sole of the foot away from the midline of the body (eversion) and to extend the foot downward away from the body at the ankle.
In the human body, the cuboid bone is one of the seven tarsal bones of the foot.
The fibula or calf bone is a leg bone on the lateral side of the tibia, to which it is connected above and below. It is the smaller of the two bones and, in proportion to its length, the most slender of all the long bones. Its upper extremity is small, placed toward the back of the head of the tibia, below the knee joint and excluded from the formation of this joint. Its lower extremity inclines a little forward, so as to be on a plane anterior to that of the upper end; it projects below the tibia and forms the lateral part of the ankle joint.
The ankle, or the talocrural region, or the jumping bone (informal) is the area where the foot and the leg meet. The ankle includes three joints: the ankle joint proper or talocrural joint, the subtalar joint, and the inferior tibiofibular joint. The movements produced at this joint are dorsiflexion and plantarflexion of the foot. In common usage, the term ankle refers exclusively to the ankle region. In medical terminology, "ankle" can refer broadly to the region or specifically to the talocrural joint.
The tibialis anterior muscle is a muscle in humans that originates along the upper two-thirds of the lateral (outside) surface of the tibia and inserts into the medial cuneiform and first metatarsal bones of the foot. It acts to dorsiflex and invert the foot. This muscle is mostly located near the shin.
The talus, talus bone, astragalus, or ankle bone is one of the group of foot bones known as the tarsus. The tarsus forms the lower part of the ankle joint. It transmits the entire weight of the body from the lower legs to the foot.
The flexor hallucis longus muscle (FHL) is one of the three deep muscles of the posterior compartment of the leg that attaches to the plantar surface of the distal phalanx of the great toe. The other deep muscles are the flexor digitorum longus and tibialis posterior; the tibialis posterior is the most powerful of these deep muscles. All three muscles are innervated by the tibial nerve which comprises half of the sciatic nerve.
The flexor digitorum longus muscle is situated on the tibial side of the leg. At its origin it is thin and pointed, but it gradually increases in size as it descends. It serves to flex the second, third, fourth, and fifth toes.
The extensor digitorum brevis muscle is a muscle on the upper surface of the foot that helps extend digits 2 through 4.
In human anatomy, the fibularis brevis is a muscle that lies underneath the fibularis longus within the lateral compartment of the leg. It acts to tilt the sole of the foot away from the midline of the body (eversion) and to extend the foot downward away from the body at the ankle.
Flexor hallucis brevis muscle is a muscle of the foot that flexes the big toe.
The quadratus plantae is separated from the muscles of the first layer by the lateral plantar vessels and nerve. It acts to aid in flexing the 2nd to 5th toes and is one of the few muscles in the foot with no homolog in the hand.
In human anatomy, the subtalar joint, also known as the talocalcaneal joint, is a joint of the foot. It occurs at the meeting point of the talus and the calcaneus.
The inferior extensor retinaculum of the foot is a Y-shaped band placed in front of the ankle-joint, the stem of the Y being attached laterally to the upper surface of the calcaneus, in front of the depression for the interosseous talocalcaneal ligament; it is directed medialward as a double layer, one lamina passing in front of, and the other behind, the tendons of the peroneus tertius and extensor digitorum longus.
The arches of the foot, formed by the tarsal and metatarsal bones, strengthened by ligaments and tendons, allow the foot to support the weight of the body in the erect posture with the least weight.
The flexor retinaculum of foot is a strong fibrous band in the foot.
The talocalcaneonavicular joint is a ball and socket joint; the rounded head of the talus is received into the concavity formed by the posterior surface of the navicular, the anterior articular surface of the calcaneus, and the upper surface of the plantar calcaneonavicular ligament.
The deltoid ligament is a strong, flat, triangular band, attached, above, to the apex and anterior and posterior borders of the medial malleolus. The deltoid ligament is composed of 4 fibers: 1. Anterior tibiotalar ligament 2. Tibiocalcaneal ligament 3. Posterior tibiotalar ligament 4. Tibionavicular ligament. It consists of two sets of fibers, superficial and deep.