Bones of the Foot - Tarsals - Metatarsals - Phalanges - TeachMeAnatomy The human foot is a very complex and highly developed structure. The bones of the foot provide mechanical support for the soft tissues, helping the foot withstand the weight of the body. The bones of the foot can be divided into three categories: Tarsals – A set of seven irregularly shaped bones. They are situated proximally in the foot, in the ankle area. Metatarsals – These bones connect the phalanges to the tarsals. There are five in number – one for each digit. Phalanges – The bones of the toes. Each toe has three phalanges – a proximal, intermediate and distal (except the big toe, which only has two phalanges). Fig 1.0 – Overview of the bones of the human foot. Tarsals The tarsal bones of the foot are organised into three rows; proximal, intermediate and distal. Proximal Group The proximal tarsal bones are the talus and the calcaneus. They form the bony framework around the proximal ankle and heel area. The talus is the most superior of the tarsal bones.

It has three articulations: Superiorly: Ankle joint – between the talus and the bones of the leg (the tibia and fibula). Inferiorly: Subtalar joint – between the talus and calcaneus. Anteriorly: Talonavicular joint – between the talus and the navicular. The main function of the talus is to transmit forces from the tibia to the heel bone (known as the calcaneus). Whilst numerous ligaments attach to the talus, it is not a site of muscle attachment or origin. Fig 1.1 – The tarsal bones of the foot. The calcaneus lies underneath the talus, and has two articulations: Superiorly: Subtalar joint – between the calcaneus and the talus. Anteriorly: Calcaneocuboid joint – between the calcaneus and the cuboid. It is thick and sturdy, acting to transmit forces from the talus to the ground. The posterior aspect of the calcaneus is marked by calcaneal tuberosity, to which the Achilles tendon attaches.

Intermediate Group The intermediate row of tarsal bones contains one bone, the navicular (given its name because it is shaped like a boat). It articulates with the talus posteriorly, the cuneiform bones anteriorly, and the cuboid bone laterally. On the plantar surface of the navicular, there is a tuberosity for the attachment of the tibialis posterior tendon. Distal Group In the distal row, there are four tarsal bones – the cuboid and the three cuneiforms. These bones articulate with the metatarsals of the foot. The cuboid is the most lateral bone in the distal row, articulating with the calcaneus posteriorly, and two metatarsals anteriorly. As the name suggests, it is shaped like a cube. The inferior surface of the cuboid is marked by a groove for the fibularis longus muscle. The three cuneiforms (lateral, intermediate and medial) are wedge shaped bones. They articulate with the navicular posteriorly, and the metatarsals anteriorly. The shape of the bones helps form a transverse arch across the foot.

Clinical Relevance: Fractures of the Talus and Calcaneus The talus and the calcaneus sit in the proximal part of the foot and ankle, and are involved in transmitting forces from the body to the ground. They are the most frequently fractured of all the tarsal bones. Talus Talar fractures occur in two places – the neck of the talus, or the body: Neck fractures are caused by excessive dorsiflexion of the foot. The neck of the talus is pushed against the tibia. In this type of fracture, the blood supply to the talus may be disturbed, leading to avascular necrosis of the bone. Body fractures usually occur from jumping from a height. In any fracture of the talus, the malleoli of the leg bones act to hold the fragments together, so there is little displacement of the fracture pieces. By Jojo (Own work) [CC-BY-SA-3.0], via Wikimedia Commons Fig 1.2 – X-ray of a calcaneal fracture. Calcaneus The calcaneus is often fractured in a ‘crush‘ type injury.

The most common mechanism of damage is falling onto the heel from a height – the talus is driven into the calcaneus. The bone can break into several pieces – known as a comminuted fracture. Upon x-ray, the calcaneus will appear shorter and wider. Even after treatment, a calcaneal fracture can cause further problems. The sub-talar joint is usually disrupted, causing the joint to become arthritic. The patient will experience pain upon inversion and eversion – which can make walking on uneven ground particularly painful. Metatarsals The metatarsals are located in the midfoot, between the tarsals and phalanges. They are numbered I-V (medial to lateral). Each metatarsal has a similar structure. They consist of a distal head and proximal base, which are joined by a shaft of bone. They have three or four articulations: Proximally: Tarsometatarsal joint – between the metatarsal bases and the cuneiforms or cuboid bones. Laterally: Intermetatarsal joint(s) – between the metatarsal and the adjacent metatarsals.

Distally: Metatarsophalangeal joint – between the metatarsal head and the proximal phalanx. Clinical Relevance: Fractures of the Metatarsal Bones Metatarsal fractures can occur by three mechanisms. The most common method of fracture is a direct blow to the foot – usually from a heavy object dropping onto the foot. Another type of metatarsal injury is a stress fracture, an incomplete fracture caused by repeated stress to the bone. It is common in athletes, and occurs most frequently to metatarsals II, III and IV. The metatarsals can also be fractured by excessive inversion of the foot. If the foot is violently inverted, the fibularis brevis muscle can avulse (‘tear off’) the base of metatarsal V. Phalanges The phalanges are the bones of the toes. Most toes have three phalanges – proximal, intermediate and distal. The great toe only has proximal and distal phalanges. Each phalanx consists of a body, a proximal extremity and a distal extremity. Metatarsal Bones Definition, Function & Anatomy | Body Maps Your message has been sent. OK We're sorry, an error occurred.

We are unable to collect your feedback at this time. However, your feedback is important to us. Please try again later. Close Metatarsals Metatarsals are part of the bones of the mid-foot and are tubular in shape. They are named by numbers and start from the medial side outward. The medial side is the same side as the big toe. They are called the first metatarsal, second metatarsal, third metatarsal, fourth metatarsal, and the fifth metatarsal. The first metatarsal is the strongest of the group. These bones are found between the phalanges of the toes and the tarsal bones. Each bone's base will move with at least one of the tarsal bones where the tarsometatarsal joint is located. The metatarsal bones are connected to the bones of the toe, or phalanges, at the knuckle of the toe, or metatarsophalangeal joint. Metatarsals are convex in shape (arch upward), are long bones, and give the foot its arch. They work with connective tissues, ligaments and tendons, to provide movement in the foot.

These bones can become fractured, strained, or inflamed from misuse or overuse. Immobilization of the foot (e.g. via casting) can help heal metatarsal fractures and sprains. Tarsals, Metatarsals, and Phalanges (The Foot) About Watch and Favorite Watch Watching this resources will notify you when proposed changes or new versions are created so you can keep track of improvements that have been made. Favorite Favoriting this resource allows you to save it in the “My Resources” tab of your account. There, you can easily access this resource later when you’re ready to customize it or assign it to your students. Tarsals, Metatarsals, and Phalanges (The Foot) The human ankle and foot bones include tarsals (ankle), metatarsals (middle bones), and phalanges (toes). Learning Objective Describe the different types of bones in the foot Key Points The human foot contains 26 bones. The foot can be subdivided into the tarsals , metatarsals , and phalanges . Terms Register for FREE to remove ads and unlock more features!

Learn more Full Text The foot contains 26 bones that are divided into three regions: the tarsals (or ankle and heel), the metatarsals (forming the sole of the foot), and the phalanges (forming the digits). While sharing a similar underlying structure with the hand, the foot is visibly and structurally different to account for its greater load-bearing and locomotive duties, and reduced fine movements. This drawing of the foot shows how it contains the proximal tarsals that form the ankle and heel; intermediate metatarsals; and the distal phalanges that form the toes. Tarsals The tarsal bones of the foot are organized into three rows: proximal, intermediate, and distal . The proximal row contains the talus, which is the most superior of the tarsals and articulates with the tibia and fibula to form the ankle joint. The talus is responsible for transmitting forces from the tibia to the heel and acts as an attachment point for numerous ligaments that strengthen the ankle joint. The calcaneus is the thickest tarsal and forms the heel of the foot.

It articulates with the talus superiorly and anteriorly with the cuboid of the distal group. Posteriorly the calcaneal tuberosity is the attachment point for the Achilles tendon . The intermediate group contains only the navicular bone, which articulates with all of the tarsals—with the exception of the calcaneus. The navicular bone plays a key role in maintaining the medial longitudinal arch of the foot. There are four distal tarsals: the lateral cuboid and the three cuneiforms, located medially. The distal tarsals articulate with the metatarsals and also maintain the transverse arch of the foot. Metatarsals The foot contains five metatarsals that are numbered I–V, moving medial to lateral, big toe to little toe. Each metatarsal consists of a head, shaft, and base . The proximal base articulates with the cuboid bones, and distally with the proximal phalanges, and each metatarsal also articulates laterally with adjacent metatarsals. The interossei of the foot originate from the shafts of the metatarsals.

Phalanges The digits are named in a similar fashion to the metatarsals, medial to lateral from the big toe. With the exception of the big toe, each digit contains a proximal, intermediate, and distal phalange; the big toe lacks an intermediate phalange. The length of the phalanges decreases distally. Ankle and Foot Home > Skeletal System > Bones of the Leg and Foot > Ankle and Foot Ankle and Foot The bones of the ankle and foot form the most distal region of the lower limb in the appendicular skeleton. These bones are responsible for the propulsion, balance, and support of the body’s weight through many diverse activities, such as standing, walking, running, and jumping. The ankle joint is formed by the union of the lower leg bones – the tibia and fibula – and the talus bone (one of a group of bones collectively known as the tarsus, located in the foot). Together, these three bones form a tight synovial hinge joint that permits the plantarflexion and dorsiflexion of the foot....

Move up/down/left/right: Click compass arrows Rotate image: Click and drag in any direction, anywhere in the frame Identify objects: Click on them in the image 2D Interactive 3D Rotate & Zoom Change Anatomical System Ankle and Foot, Posterior (Back) Full Ankle and Foot Description [Continued from above] . . . Plantarflexion is the movement that describes the pointing of the foot toward the ground, as in standing on one’s tiptoes. Dorsiflexion is the opposite of plantarflexion and involves the movement of the foot away from the ground, as in pulling the toes up and walking on one’s heels. The medial malleolus of the tibia and the lateral malleolus of the fibula form a cup surrounding the rounded tarsus to prevent lateral movement at the ankle joint. The fibula is united to the bones of the foot on the lateral side of the ankle by the anterior and posterior talofibular ligaments and the calcaneofibular ligament. On the medial side, the wide deltoid ligament binds the tibia to the tarsal bones of the foot.

All of these ligaments work together to limit extreme movements and dislocations of the ankle joint while providing slight lateral flexibility that helps the body walk on uneven surfaces and maintain its balance. Twenty-six small bones of the foot provide the strength and flexibility necessary for bipedal locomotion. The seven tarsal bones form the posterior portion of the foot nearest to the heel. Each tarsal bone is a short bone with many flat facets that allow the tarsals to glide past one another. This gliding motion provides lateral mobility to the foot below the level of the ankle joint and allows the foot to bend to adjust the body’s balance. Anterior to the tarsals are the five long metatarsal bones of the foot and the fourteen phalanges of the toes. The metatarsals, phalanges, and tarsals form the longitudinal and transverse arches of the foot to divide the body’s weight across the entire foot and act as a spring to absorb and release the force of the body’s weight on the ground. These bones also act as a lever to increase the strength of the muscles acting on the ankle joint, allowing the body to easily lift its entire weight up on the balls of the foot and the toes.

This leverage is essential to rapid locomotion and jumping as it greatly increases the strength and speed of the legs. Many different ligaments hold the bones of the foot firmly together while providing flexibility to the bones. Amongst the tarsal bones, the plantar calcaneonavicular ligament joins the navicular bone to the calcaneus (heel bone), while the plantar cuboideonavicular ligament joins the navicular bone to the cuboid bone. The dorsal and plantar tarsometatarsal ligaments bind the tarsal and metatarsal bones together, support the arches of the foot, and strengthen overall structure of the foot. In the anterior of the foot, the plantar metatarsal ligaments bind the instep across the sole of the foot. Prepared by Tim Taylor, Anatomy and Physiology Instructor Metatarsus | definition of metatarsus by Medical dictionary Metatarsus | definition of metatarsus by Medical dictionary Related to metatarsus: metatarsus primus varus metatarsus [met″ah-tahr´sus] the part of the foot between the ankle and the toes, its skeleton being the five bones (metatarsals) extending from the tarsus to the phalanges.

See appendix 3-3. metatarsus pri´mus va´rus angulation of the first metatarsal bone toward the midline of the body, producing an angle sometimes of 20 degrees or more between its base and that of the second metatarsal bone. met·a·tar·sus me·ta·tar·si (met'ă-tar'sŭs, -sī), The distal portion of the foot between the instep and the toes, having as its skeleton the five long bones (metatarsal bones) articulating proximally with the cuboid and cuneiform bones and distally with the phalanges. [meta- + G. tarsos, tarsus] metatarsus /meta·tar·sus/ (-tahr´sus) the part of the foot between the ankle and the toes, its skeleton being the five bones (metatarsals) extending from the tarsus to the phalanges. metatarsus (mĕt′ə-tär′səs) n. pl. metatar·si (-sī, -sē) 1.

The middle part of the human foot that forms the instep and includes the five bones between the toes and the ankle. 2. The corresponding part of the hind foot in quadrupeds or of the foot in birds. metatarsus [-tär′səs] Etymology: Gk, meta + tarsos, flat surface a part of the foot, consisting of five bones, numbered I to V from the medial side. Each bone has a long, slender body; a wedge-shaped proximal end; a convex distal end; and flattened, grooved sides for the attachment of ligaments. The metatarsal bones articulate with the tarsus proximally and the first row of phalanges distally. Deformities of the metatarsus include metatarsus valgus and metatarsus varus. -metatarsal, adj. Metatarsal bones The foot region between the ankle and phalanges, including the five metatarsal bones. met·a·tar·sus , pl.

metatarsi (met'ă-tahr'sŭs, -sī) The part of the foot between the tarsus and the toes, having as its skeleton the five long bones (metatarsal bones) articulating posteriorly with the cuboid and cuneiform bones and distally with the phalanges. [meta- + G. tarsos, tarsus] The five bones of the foot. metatarsus the skeleton of the foot between the toes and the tarsus of a TETRAPOD consisting of the five bones of the hind limb. In humans this forms the middle and hind part of the foot. see PENTADACTYL LIMB . metatarsus area of foot between midfoot and toes, the bones of which (i.e. metatarsals 1-5) articulate proximally with the medial, intermediate and lateral cuneiforms and cuboid, and distally with bases of proximal phalanges of toes 1-5 metatarsus the part of the hindlimb between the tarsus and the first phalanx. In the cat and dog it contains five bones (metatarsals) extending from the tarsus to the phalanges.

See also Table 10. metatarsus primus varus angulation of the first metatarsal bone toward the midline of the body, producing an angle sometimes of 20 degrees or more between its base and that of the second metatarsal bone. Foot Bone Anatomy: Overview, Tarsal Bones - Gross Anatomy, Metatarsal Bones - Gross Anatomy Foot Bone Anatomy Author: Vinod K Panchbhavi, MD, FACS; Chief Editor: Thomas R Gest, PhD more... Share Overview Overview The human foot is a highly developed, biomechanically complex structure that serves to bear the weight of the body as well as forces many times the weight of the human body during propulsion. About 26 bones in the human foot provide structural support. They can be grouped into 3 parts, as follows [ 1 , 2 ] : The tarsal bones (7) [ 3 , 4 ] The metatarsal bones (5) [ 5 ] The phalanges (14) [ 6 ] Apart from these main bones, the sesamoid bones help improve function and are often found as variants of the accessory bones.

The foot itself can be divided into 3 parts: the hindfoot, the midfoot, and the forefoot. The hindfoot is composed of 2 of the 7 tarsal bones, the talus, and the calcaneus; the midfoot contains the rest of the tarsal bones; and the forefoot contains the metatarsals and the phalanges. The images below depict the bones of the foot. Bones of the foot, dorsal and ventral views. Next: Tarsal Bones - Gross Anatomy The tarsal bones are 7 in number. They are named the calcaneus, talus, cuboid, navicular, and the medial, middle, and lateral cuneiforms. Calcaneus The calcaneus is the largest of the tarsal bones located in the heel of the foot and bears the weight of the body as the heel hits the ground. This bone protrudes out at the back, providing a strong lever for the triceps surae muscles of the calf and helping with plantar flexion and push off during ambulation (see the image below).

The calcaneus is roughly 3-dimensionally rectangular in shape, with its long axis directed anteriorly and laterally, and it has 6 surfaces. Ankle joint, lateral view. View Media Gallery Calcaneus, surface anatomy The superior calcaneal surface (see the following images) of the calcaneus has 2 parts: articular and nonarticular. The nonarticular part extends posteriorly to form the heel; it varies in length in different individuals, is convex from side to side, is concave in the anteroposterior axis, and supports a fat pad situated anterior to the calcaneal (Achilles) tendon. The articular part that lies anterior to the nonarticular part of the superior surface has an oval facet; the posterior facet faces superiorly and is also tilted anteriorly. The articular portion of the superior surface is convex in the anteroposterior axis and articulates with the posterior calcaneal facet on the undersurface of the talus. Superior surface of the calcaneus bone. View Media Gallery At the anterior boundary of the posterior facet is a deep depression, which continues posteromedially in the form of a groove.

This groove is called the calcaneal sulcus. It matches the inferior similar sulcus underneath the talus, and both these grooves form a canal in the hindfoot called the sinus tarsi. Just anteromedial to the calcaneal sulcus is another area of articular surface elongated and concave in its long axis that is directed anterolaterally. This articular surface is divided by a transversely oriented notch into a larger facet, called the middle facet, as well as a smaller facet anterior to this, called the anterior facet (see the previous image). The middle facet lies on a medially projecting process of the calcaneus called the sustentaculum tali (see the image below). It articulates with the middle calcaneal facet on the under surface of the talus. The anterior facet lies on the anterior process of the calcaneus and articulates with the anterior calcaneal facet on the talus. The upper surface, anterior and lateral to the facets, is rough for the attachment of ligaments and for the origin of the extensor digitorum brevis. Medial surface of the calcaneus bone.

View Media Gallery The inferior or plantar calcaneal surface is wider posteriorly and convex from side to side. It has a plantar prominence at the back, called the calcaneal tuberosity (see the following image), which has a central longitudinal depression dividing it into a smaller lateral process that is the origin of a part of the abductor digiti minimi (quinti), as well as a larger broader medial process that gives attachment, by its prominent medial margin, to the abductor hallucis, and in front to the flexor digitorum brevis and the plantar aponeurosis. Lateral view of the calcaneus and cuboid bones. View Media Gallery The depression between the processes gives rise to the abductor digiti minimi (quinti). The rough surface in front of the processes gives attachment to the long plantar ligament and to the lateral head of the quadratus plantae. The plantar calcaneocuboid ligament is attached to a prominent tubercle nearer the anterior part of this surface, as well as to a transverse groove in front of the tubercle. The lateral calcaneal surface (see the image below) is broader posteriorly and becomes narrower anteriorly.

It has a small tubercle in the middle, to which the calcaneofibular ligament is attached. Anterior to this tubercle are 2 grooves separated by a ridge, the trochlear process or peroneal (fibular) tubercle. The fibularis (peroneus) brevis tendon lies superior and the fibularis (peroneus) longus tendon lies inferior to the peroneal (fibular) tubercle. Lateral surface of the calcaneus bone. View Media Gallery The medial calcaneal surface (see the first image below) has a deep concavity in the anteroposterior direction in which run the neurovascular structures from the leg into the foot. Toward the upper and anterior end is a medially oriented horizontal projection, the sustentaculum tali (see the second image below). The sustentaculum tali has an articular surface for the middle calcaneal facet and is grooved inferiorly to house the flexor hallucis longus tendon. Its anterior margin gives attachment to the plantar calcaneonavicular ligament, and its medial margin gives attachment to a part of the deltoid ligament of the ankle joint.

Medial surface of the calcaneus bone. View Media Gallery Talus The talus is the second largest tarsal bone, and it is situated above the calcaneus in the hindfoot. This bone is unique in that two thirds of the talar surface is covered with articular cartilage, and neither tendons nor muscles insert or originate from this bone. The talus has 5 articular surfaces, all of which have a weight-bearing function. The talus is composed of 3 parts (the head, neck, body) and 2 processes (the lateral and posterior). The talar head is the portion that articulates mostly with the navicular. The body includes the dome of the talus at the ankle joint and the posterior facet at the subtalar joint. Between the head and the body is the neck, which does not articulate with the ankle and sits over the sinus tarsi below. The body and neck of the talus are not coaxial, because in the horizontal plane the neck angles medially with a variable angle of declination. Talus, head The talar head looks forward and medialward; its anterior articular or navicular surface is large, oval, and convex.

The anteroinferior medial portion of the talar head is quadrilateral or oval and provides articulation with the anterior facet of the calcaneus. This portion of the head is flat and continuous anteriorly with the navicular articular surface (see the images below). Anterior view of the talus and calcaneus bones. View Media Gallery The head of the talus nests within an articulation known as the acetabulum pedis, or foot socket (see image below), as described by Sarrafian. [ 2 ] This socket is formed by the calcaneal middle and anterior surfaces connected to the large navicular articular surface by the inferior and superomedial calcaneonavicular ligaments. The acetabulum pedis has a variable volume capacity and adapts to the changing position of the talar head during gait. It is hinged laterally by the lateral calcaneonavicular component of the bifurcate ligament and medially by the posterior tibial tendon and the spring ligament. Superior view of the acetabulum pedis.

View Media Gallery Talus, neck The neck is directed forward and medialward 15-20º and comprises the constricted portion of the bone between the body and the oval head (see the following image). This portion of the talus is most vulnerable to fracture. The neck has 4 surfaces: (1) superior, (2) lateral, (3) medial, and (4) inferior. Medial surface of the talus bone. View Media Gallery The superior surface of the neck is limited posteriorly by the anterior border of the trochlea of the talus (the dome or body) and anteriorly by the articular surface of the talar head. The tibiotalar capsule inserts along this superior surface just proximal to the insertion of the capsule of the talonavicular joint. The lateral surface of the neck is concave and is continuous below with the deep groove for the interosseous talocalcaneal ligament. It provides an insertion for the medial aspect of the inferior extensor retinaculum. The inferior surface of the neck forms the roof of the sinus tarsi and sinus canal. The medial surface provides an area for insertion of the talonavicular ligaments.

Talus, body The body of the talus is arbitrarily divided into 5 surfaces: (1) lateral, (2) medial, (3) superior, (4) inferior, and (5) posterior. The lateral talar body surface carries a large triangular facet, concave from above downward, for articulation with the lateral malleolus (see the image below). It is continuous above with the superior articular surface and in front of it is a rough depression for the attachment of the anterior talofibular ligament. Along the anterior, inferior, and posterior perimeter of this lateral articular surface is the lateral process, a nonarticular component of the talus. The lateral talocalcaneal ligament inserts at the inferior tip of the lateral process. Along the anterior border of the triangular lateral process are 2 tubercles for insertion of the anterior talofibular ligament. Along the posteroinferior border of this lateral surface lies a groove for the attachment of the posterior talofibular ligament. Lateral surface of the talus bone. View Media Gallery The medial talar body surface of the body presents 2 areas, superior and inferior(see the following image).

The superior portion is occupied by a pear-shaped or comma-shaped articular facet, which is broader anteriorly and is called the medial malleolar facet. It articulates with the medial malleolus of the tibia and is continuous above with the superior articular surface for tibia. The long-axis medial malleolar facet is oriented anteroposteriorly. The inferior portion is nonarticular, and its anterior half is a depressed surface perforated by numerous vascular foramina. Under the tail of the medial malleolar facet, the posterior half of the inferior portion consists of a large oval area that provides insertion for the deep component of the deltoid ligament. Medial surface of the talus bone. View Media Gallery The superior surface of the talar body is completely covered with articular cartilage for articulation with the tibia. It is shaped like a pulley, with the groove of the pulley termed the trochlea, closer to the medial border. The superior surface is broader in front than behind, convex anteroposterior axis, slightly concave from side to side: in front, it is continuous with the upper surface of the neck of the bone (see image below). Superior surface of the talus bone.

View Media Gallery The inferior talar body surface presents 2 articular areas called the posterior calcaneal articular surface and the middle calcaneal articular surface . These articular surfaces, one for the posterior and the other for the middle calcaneal facets, are separated from each other by a deep groove, the sulcus tali. The groove runs obliquely forward and lateralward, becoming gradually broader and deeper in front. In the articulated hindfoot it lies above a similar groove upon the upper surface of the calcaneus, and forms, with it, a canal termed the sinus tarsi, in which lies the interosseous talocalcaneal ligament. The posterior calcaneal articular surface is large and of an oval or oblong form. It articulates with the corresponding facet on the upper surface of the calcaneus and is deeply concave in the direction of its long axis, which runs forward and lateralward at an angle of about 45° with the median plane of the body. The middle calcaneal articular surface is small, oval in form and slightly convex; it articulates with the upper surface of the sustentaculum tali of the calcaneus(see the first image below).

The posterior surface is narrow, and traversed by a groove running obliquely downward and medialward and transmitting the tendon of the flexor hallucis longus (see the second image below). Medial view of the talus and calcaneal bones. View Media Gallery The sulcus for this tendon is flanked by the posterolateral and posteromedial tubercles. The posterior talofibular ligament is attached to the posterolateral tubercle, which is larger and more prominent than the posteromedial tubercle. The posterolateral tubercle contributes an inferior articular surface that is in continuity with the posterolateral aspect of the posterior calcaneal surface of the talus. An accessory bone, the os trigonum, may be found in connection with the posterolateral tubercle. Talus, articulations The talus articulates with 4 bones: the tibia, fibula, calcaneus, and navicular. Cuboid The cuboid bone is placed on the lateral side of the foot, in front of the calcaneus, and behind the fourth and fifth metatarsal bones. It is cuboidal in shape but has a broader base oriented medially (see the image below).

Lateral view of the calcaneus and cuboid bones. View Media Gallery Cuboid, surfaces The dorsal cuboidal surface, directed upward and lateralward, is rough, for the attachment of ligaments. The plantar surface appears in front of a deep groove, the peroneal (fibularis) sulcus, which runs obliquely anteromedially. It lodges the tendon of the fibularis (peroneus) longus and is bounded behind by a prominent ridge, to which the long plantar ligament is attached. The ridge ends laterally in an eminence, the tuberosity, the surface of which presents an oval facet; on this facet glides the sesamoid bone or cartilage frequently found in the tendon of the fibularis (peroneus) longus. The surface of bone behind the groove is rough, for the attachment of the plantar calcaneocuboid ligament, a few fibers of the flexor hallucis brevis, and a fasciculus from the tendon of the tibialis posterior. The lateral cuboidal surface presents a deep notch formed by the commencement of the peroneal (fibularis) sulcus.

The posterior surface is smooth, triangular, and concavoconvex, for articulation with the anterior surface of the calcaneus; its inferomedial angle projects backward as a process, which underlies and supports the anterior end of the calcaneus. The anterior cuboidal surface, of smaller size, but also irregularly triangular, is divided by a vertical ridge into 2 facets: the medial, quadrilateral in form, articulates with the fourth metatarsal; the lateral, larger and more triangular, articulates with the fifth metatarsal. The medial surface is broad, irregularly quadrilateral, and presents at its middle and upper part a smooth, oval facet, for articulation with the third cuneiform; and behind this (occasionally), a smaller facet, for articulation with the navicular; it is rough in the rest of its extent, for the attachment of strong interosseous ligaments. Cuboid, articulations The cuboid articulates with 4 bones: (1) calcaneus, (2) third cuneiform, (3) fourth metatarsal, and (4) fifth metatarsal. It occasionally articulates with a fifth, the navicular.

Navicular bone The navicular bone is located medially in the midfoot between the talus posteriorly and the 3 cuneiform bones anteriorly (see the following image). It forms the uppermost portion of the medial longitudinal arch of the foot and acts as a keystone of the arch. It is a boat-shaped bone that sits between the talar head and the 3 cuneiform bones. The navicular bone has 6 surfaces. Bones of the foot, larger lateral view. View Media Gallery Navicular bone, surfaces The posterior navicular surface is oval, concave, broader laterally than medially, and articulates with the rounded head of the talus (see the image below). Posterior surface of the navicular bone. View Media Gallery The medial navicular surface slopes posteriorly to end in a rounded prominent tuberosity (see the image below), where a portion of the posterior tibial tendon is inserted. Much of the tuberosity accepts the attachment of the plantar calcaneonavicular (spring) ligament arising from the sustentaculum tali. Superior view of the talus and navicular bones.

View Media Gallery The anterior navicular surface is convex from side to side, and subdivided by 2 ridges into 3 facets, for articulation with the 3 cuneiform bones. The dorsal surface is convex from side to side, and rough for the attachment of ligaments (see the following image). The plantar surface is irregular, and also rough for the attachment of ligaments. The lateral surface is rough and irregular for the attachment of ligaments and occasionally presents a small facet for articulation with the cuboid bone. Dorsal surface of the navicular bone. View Media Gallery Navicular bone, articulations The navicular articulates with 4 bones: the talus and the 3 cuneiforms. It occasionally articulates with a fifth, the cuboid. Cuneiforms The 3 cuneiforms are named the medial, middle, and lateral, and they are convexly shaped on their broader dorsal surfaces. The middle and the lateral cuneiforms are also wedge shaped, so that the apex of each bone points plantarward and toward the center of the foot. The medial cuneiform is convex medially and rounded inferiorly.

The medial and lateral cuneiforms project farther distally that the middle cuneiform to create a mortise for the base of the second metatarsal that articulates with the middle cuneiform. This configuration creates a keystone effect and contributes to the stability of the midfoot. See the following images. Bones of the foot, dorsal and ventral views. View Media Gallery Medial cuneiform overview, surfaces, and articulations The medial cuneiform bone is the largest of the 3 cuneiforms. It is situated at the medial side of the foot, between the navicular behind and the base of the first metatarsal in front. The medial surface of the medial cuneiform is subcutaneous, broad, and quadrilateral. At its anterior inferior edge is a smooth oval impression, into which part of the tendon of the tibialis anterior is inserted; in the rest of its extent, it is rough for the attachment of ligaments.

The lateral surface is concave, presenting, along its superior and posterior borders a narrow L-shaped surface, the vertical limb and posterior part of the horizontal limb which articulate with the second cuneiform, whereas the anterior part of the horizontal limb articulates with the second metatarsal bone. The rest of this surface is rough for the attachment of ligaments and part of the tendon of the fibularis (peroneus) longus. The anterior surface, kidney shaped and much larger than the posterior surface, articulates with the first metatarsal bone. The posterior surface is triangular, concave, and articulates with the most medial and largest of the 3 facets on the anterior surface of the navicular. The plantar surface is rough and forms the base of the wedge; at its back part is a tuberosity for the insertion of part of the tendon of the tibialis posterior. It also gives insertion in front to part of the tendon of the tibialis anterior. The dorsal surface is the narrow end of the wedge and is directed upward and lateralward; it is rough for the attachment of ligaments.

The first cuneiform articulates with 4 bones: (1) navicular, (2) second cuneiform, (3) first metatarsal, and (4) second metatarsal. Middle cuneiform overview, surfaces, and articulations The second cuneiform bone, the smallest of the 3, is wedge shaped with a dorsal base and apex plantar. It is situated between the other 2 cuneiforms, and articulates with the navicular behind and the second metatarsal in front. The anterior surface of the middle cuneiform bone, triangular in form, and narrower than the posterior, articulates with the base of the second metatarsal bone. The posterior surface, also triangular, articulates with the intermediate facet on the anterior surface of the navicular. The medial surface carries an L-shaped articular facet, running along the superior and posterior borders, for articulation with the first cuneiform, and is rough in the rest of its extent for the attachment of ligaments. The lateral surface presents posteriorly a smooth facet for articulation with the third cuneiform bone. The dorsal surface forms the base of the wedge; it is quadrilateral and rough for the attachment of ligaments.

The plantar surface, sharp and tuberculated, is also rough for the attachment of ligaments and for the insertion of a slip from the tendon of the tibialis posterior. The medial cuneiform articulates with 4 bones: (1) navicular, (2) first cuneiform, (3) third cuneiform, and (4) second metatarsal. Lateral cuneiform overview, surfaces, and articulations The anterior surface of the lateral cuneiform is triangular and articulates with the third metatarsal bone. The posterior surface articulates with the lateral facet on the anterior surface of the navicular and is rough below for the attachment of ligamentous fibers. The medial surface of the lateral cuneiform presents an anterior and a posterior articular facet, separated by a rough depression: the anterior, sometimes divided, articulates with the lateral side of the base of the second metatarsal bone; the posterior skirts the posterior border and articulates with the second cuneiform; the rough depression gives attachment to an interosseous ligament.

The lateral surface of the lateral cuneiform also presents 2 articular facets, separated by a rough nonarticular area; the anterior facet, situated at the superior angle of the bone, is small and semi-oval in shape, and articulates with the medial side of the base of the fourth metatarsal bone; the posterior and larger one is triangular or oval and articulates with the cuboid; the rough, nonarticular area serves for the attachment of an interosseous ligament. The 3 facets for articulation with the 3 metatarsal bones are continuous with one another; those facets for articulation with the second cuneiform and navicular are also continuous, but the facet for articulation with the cuboid is usually separate. The dorsal surface is oblong, its posterolateral angle being prolonged backward; whereas the plantar surface is a rounded margin and serves for the attachment of part of the tendon of the tibialis posterior, part of the flexor hallucis brevis, and ligaments.

The third cuneiform articulates with 6 bones: (1) navicular, (2) second cuneiform, (3) cuboid, and (4-6) second, third, and fourth metatarsals. Previous View Media Gallery The base at the proximal end is wedge-shaped, articulating proximally with the tarsal bones and by its sides with the contiguous metatarsal bones; its dorsal and plantar surfaces are rough for the attachment of ligaments. The head at the distal end presents a convex articular surface, oblong from above downward, and extending farther backward plantar than dorsal. Its sides are flattened, and on each is a depression, surmounted by a tubercle, for ligamentous attachment. Its plantar surface is grooved anteroposteriorly (for the passage of the flexor tendons) and marked on either side by an articular eminence continuous with the terminal articular surface. First metatarsal bone The first metatarsal bone is the stoutest and the shortest of the metatarsal bones. The body is strong and of well-marked prismoid form.

The base usually has no articular facets on its sides, but occasionally on the lateral side an oval facet exists, by which it articulates with the second metatarsal. Its proximal articular surface is of large size and kidney shaped; its circumference is grooved (for the tarsometatarsal ligaments) and medially gives insertion to part of the tendon of the tibialis anterior; its plantar angle presents a rough, oval prominence for the insertion of the tendon of the fibularis (peroneus) longus. The head is large; on its plantar surface are 2 grooved facets, on which glide sesamoid bones; the facets are separated by a smooth elevation. Second metatarsal bone The second metatarsal bone is the longest of the metatarsal bones, as it extends proximally the most, articulating with the recessed middle cuneiform. Its base is broad above, narrow and rough below.

It presents 4 articular surfaces: one behind, of a triangular form, for articulation with the second cuneiform; one at the upper part of its medial surface, for articulation with the first cuneiform; and 2 on its lateral surface, an upper and lower, separated by a rough nonarticular interval. Each of these lateral articular surfaces is divided into 2 by a vertical ridge; the 2 anterior facets articulate with the third metatarsal; the 2 posterior (sometimes continuous) with the third cuneiform. A fifth facet is occasionally present for articulation with the first metatarsal; it is oval in shape and situated on the medial side of the body near the base. Third metatarsal bone The third metatarsal bone articulates proximally, by means of a triangular smooth surface, with the third cuneiform; medially, by 2 facets, with the second metatarsal; and laterally, by a single facet, with the fourth metatarsal. This last facet is situated at the dorsal angle of the base.

Fourth metatarsal bone The fourth metatarsal bone is smaller than the preceding metatarsal bones; its base presents an oblique quadrilateral surface for articulation with the cuboid; a smooth facet on the medial side, divided by a ridge into an anterior portion for articulation with the third metatarsal, and a posterior portion for articulation with the third cuneiform. On the lateral side, a single facet, for articulation with the fifth metatarsal, can be found. Fifth metatarsal bone The fifth metatarsal bone is recognized by a rough eminence, the tuberosity, on the lateral side of its base. The base articulates behind, by a triangular surface cut obliquely in a transverse direction, with the cuboid, and medially, with the fourth metatarsal. The tendon of the fibularis (peroneus) tertius inserts on the medial part of its dorsal surface. The fibularis (peroneus) brevis inserts on the dorsal surface of the tuberosity. A strong band of the plantar aponeurosis connects the projecting part of the tuberosity with the lateral process of the tuberosity of the calcaneus.

The plantar surface of the base is grooved for the tendon of the abductor digiti (minimi) quinti and gives origin to the flexor digiti minimi (quinti) brevis. Metatarsal articulations The base of each metatarsal bone articulates with one or more of the tarsal bones, and the head articulates with one of the first row of phalanges. The first metatarsal articulates with the first cuneiform, the second with all 3 cuneiforms, the third with the third cuneiform, the fourth with the third cuneiform and the cuboid, and the fifth with the cuboid. Previous View Media Gallery Proximal phalanges The body of each proximal phalanx is similar to the metatarsals in being convex above and concave below. The base is concave for articulation with the respective metatarsal, and the head presents a trochlear surface for articulation with the second phalanx. Middle phalanges The middle phalanges are smaller than the proximal ones but larger than the distal phalanges; the features at the base and head are similar to the proximal phalanges.

Distal phalanges The distal phalanges are flattened from above downward; each presents a broad base for articulation with the corresponding bone of the second row and an expanded distal tip for the support of the nail and end of the toe. Sesamoids of the foot Galen apparently first coined the term sesamoid because of the resemblance of these small rounded bones to the sesame seed. [ 7 ] The location of the sesamoids in the foot is constant, but the frequency of occurrence may vary. [ 8 ] The sesamoids give a mechanical advantage to the musculotendinous unit in which they are located and reduce friction and pressure in the nearby joint. The sesamoids may be totally or partially contained within the tendinous structure, and they may ossify or remain cartilaginous or partially ossify with a fibrocartilaginous interface between the ossified fragments. This variability in ossification might explain the radiographic absence or presence of various sesamoid bones, as well as the incidence of bipartism of sesamoids. Previous Superior view of the acetabulum pedis. Medial view of the talus and calcaneal bones.

Lateral view of talus and calcaneal bones. Anterior view of the talus and calcaneus bones. Lateral view of the calcaneus and cuboid bones. Anterior surface of the calcaneus bone. Lateral surface of the calcaneus bone. Medial surface of the calcaneus bone. Superior surface of the calcaneus bone. Superior surface of the talus bone. Medial surface of the talus bone. Lateral surface of the talus bone. Posterior surface of the talus bone. Inferior surface of the talus bone. Superior view of the talus and navicular bones. Posterior surface of the navicular bone. Dorsal surface of the navicular bone. of 23

Question: Which parts of the body are formed by the bones of the metatarsals and phalanges?
Answer: Feet