Arches of the foot
Encyclopedia
The arches of the foot are formed by the tarsal
and metatarsal bones and, strengthened by ligaments and tendons, allow the foot to support the weight of the body in the erect posture with the least weight.
The arches are categorized as transverse and longitudinal arches of the foot.
The main arches are the antero-posterior arches, which may, for descriptive purposes, be regarded as divisible into two types—a medial and a lateral.
, the navicular, the three cuneiforms, and the first, second, and third metatarsals.
Its summit is at the superior articular surface of the talus, and its two extremities or piers, on which it rests in standing, are the tuberosity on the plantar surface of the calcaneus posteriorly and the heads of the first, second, and third metatarsal bones anteriorly. The chief characteristic of this arch is its elasticity, due to its height and to the number of small joints between its component parts.
Its weakest part (i.e., the part most liable to yield from overpressure) is the joint between the talus and navicular, but this portion is braced by the plantar calcaneonavicular ligament
a.k.a spring ligament, which is elastic and is thus able to quickly restore the arch to its pristine condition when the disturbing force is removed. The ligament is strengthened medially by blending with the deltoid ligament of the ankle-joint, and is supported inferiorly by the tendon of the Tibialis posterior, which is spread out in a fanshaped insertion and prevents undue tension of the ligament or such an amount of stretching as would permanently elongate it.
The arch is further supported by the plantar aponeurosis, by the small muscles in the sole of the foot, by the tendons of the Tibialis anterior and posterior and Peronæus longus, and by the ligaments of all the articulations involved.
Its summit is at the talocalcaneal articulation, and its chief joint is the calcaneocuboid, which possesses a special mechanism for locking, and allows only a limited movement. The most marked features of this arch are its solidity and its slight elevation; two strong ligaments, the long plantar and the plantar calcaneocuboid, together with the Extensor tendons and the short muscles of the little toe, preserve its integrity.
At the posterior part of the metatarsus and the anterior part of the tarsus the arches are complete, but in the middle of the tarsus they present more the characters of half-domes the concavities of which are directed downward and medialward, so that when the medial borders of the feet are placed in apposition a complete tarsal dome is formed. The transverse arches are strengthened by the interosseous, plantar, and dorsal ligaments, by the short muscles of the first and fifth toes (especially the transverse head of the Adductor hallucis), and by the Peronæus longus, whose tendon stretches across between the piers of the arches.
s can spread ground contact reaction forces over a longer time period, and thus reduce the risk of musculoskeletal wear or damage, and they can also store the energy of these forces, returning it at the next step and thus reducing the cost of walking and, particularly, running, where vertical forces are higher. The non-human apes (the gibbons, mountain and lowland gorillas, orang-utan, chimpanzee and bonobo) tend to walk on the lateral side of the foot, that is with an 'inverted' foot, which may reflect a basic adaptation to walking on branches. It is often held that their feet lack longitudinal arches, but footprints made by bipedally walking apes, which must directly or indirectly reflect the pressure they exert to support and propel themselves do suggest that they exert lower foot pressure under the medial part of their midfoot. However, human feet, and the human medial longitudinal arch, differ in that the anterior part of the foot is medially twisted on the posterior part of the foot, so that all the toes may contact the ground at the same time, and the twisting is so marked that the most medial toe, the big toe or hallux, (in some individuals the second toe) tends to exert the greatest propulsive force in walking and running. This gives the human foot an 'everted' or relatively outward-facing appearance compared to that of other apes. The strong twisting of the anterior part of the human foot on the posterior part tends to increase the height of the medial longitudinal arch. However, there is now considerable evidence that shoe-wearing also accentuates the height of the medial longitudinal arch and that the height of the medial longitudinal arch also differs very considerably between individuals and at different speeds. It is not yet agreed to what extent the early human ancestor Australopithecus afarensis
, (3.75 million years ago onwards) had acquired a functionally human-like foot, but the medial twist of the forefoot evident in fossil footbones of this species, and in the Laetoli
footprint trail in Tanzania generally attributed to this species, certainly appears less marked than is evident in fossil footbones of Homo erectus
(sometimes called Homo georgicus
) from Dmanisi
, Georgia (c. 1. 8 million years ago) and the roughly contemporaneous fossil footprint trail at Ileret
, Kenya attributed to Homo erectus ergaster.
Tarsus (skeleton)
In tetrapods, the tarsus is a cluster of articulating bones in each foot situated between the lower end of tibia and fibula of the lower leg and the metatarsus. In the foot the tarsus articulates with the bones of the metatarsus, which in turn articulate with the bones of the individual toes...
and metatarsal bones and, strengthened by ligaments and tendons, allow the foot to support the weight of the body in the erect posture with the least weight.
The arches are categorized as transverse and longitudinal arches of the foot.
Longitudinal arches
The Longitudinal arch of the foot can be broken down into several smaller arches:The main arches are the antero-posterior arches, which may, for descriptive purposes, be regarded as divisible into two types—a medial and a lateral.
Medial arch
The medial arch is made up by the calcaneus, the talusTalus bone
-External links:* *...
, the navicular, the three cuneiforms, and the first, second, and third metatarsals.
Its summit is at the superior articular surface of the talus, and its two extremities or piers, on which it rests in standing, are the tuberosity on the plantar surface of the calcaneus posteriorly and the heads of the first, second, and third metatarsal bones anteriorly. The chief characteristic of this arch is its elasticity, due to its height and to the number of small joints between its component parts.
Its weakest part (i.e., the part most liable to yield from overpressure) is the joint between the talus and navicular, but this portion is braced by the plantar calcaneonavicular ligament
Plantar calcaneonavicular ligament
The plantar calcaneonavicular ligament is a ligament on the underside of the foot that connects the calcaneus with the navicular bone.-Structure:...
a.k.a spring ligament, which is elastic and is thus able to quickly restore the arch to its pristine condition when the disturbing force is removed. The ligament is strengthened medially by blending with the deltoid ligament of the ankle-joint, and is supported inferiorly by the tendon of the Tibialis posterior, which is spread out in a fanshaped insertion and prevents undue tension of the ligament or such an amount of stretching as would permanently elongate it.
The arch is further supported by the plantar aponeurosis, by the small muscles in the sole of the foot, by the tendons of the Tibialis anterior and posterior and Peronæus longus, and by the ligaments of all the articulations involved.
Lateral arch
The lateral arch is composed of the calcaneus, the cuboid, and the fourth and fifth metatarsals.Its summit is at the talocalcaneal articulation, and its chief joint is the calcaneocuboid, which possesses a special mechanism for locking, and allows only a limited movement. The most marked features of this arch are its solidity and its slight elevation; two strong ligaments, the long plantar and the plantar calcaneocuboid, together with the Extensor tendons and the short muscles of the little toe, preserve its integrity.
Fundamental longitudinal arch
While these medial and lateral arches may be readily demonstrated as the component antero-posterior arches of the foot, yet the fundamental longitudinal arch is contributed to by both, and consists of the calcaneus, cuboid, third cuneiform, and third metatarsal: all the other bones of the foot may be removed without destroying this arch.Transversal arch
In addition to the longitudinal arches the foot presents a series of transverse arches.At the posterior part of the metatarsus and the anterior part of the tarsus the arches are complete, but in the middle of the tarsus they present more the characters of half-domes the concavities of which are directed downward and medialward, so that when the medial borders of the feet are placed in apposition a complete tarsal dome is formed. The transverse arches are strengthened by the interosseous, plantar, and dorsal ligaments, by the short muscles of the first and fifth toes (especially the transverse head of the Adductor hallucis), and by the Peronæus longus, whose tendon stretches across between the piers of the arches.
Function and Evolution of the Arches of the Foot
The medial longitudinal arch in particular creates a space for soft tissues with elastic properties, which act as springs, particularly the thick plantar aponeurosis, passing from the heel to the toes. Because of their elastic properties, these soft tissueSoft tissue
In anatomy, the term soft tissue refers to tissues that connect, support, or surround other structures and organs of the body, not being bone. Soft tissue includes tendons, ligaments, fascia, skin, fibrous tissues, fat, and synovial membranes , and muscles, nerves and blood vessels .It is sometimes...
s can spread ground contact reaction forces over a longer time period, and thus reduce the risk of musculoskeletal wear or damage, and they can also store the energy of these forces, returning it at the next step and thus reducing the cost of walking and, particularly, running, where vertical forces are higher. The non-human apes (the gibbons, mountain and lowland gorillas, orang-utan, chimpanzee and bonobo) tend to walk on the lateral side of the foot, that is with an 'inverted' foot, which may reflect a basic adaptation to walking on branches. It is often held that their feet lack longitudinal arches, but footprints made by bipedally walking apes, which must directly or indirectly reflect the pressure they exert to support and propel themselves do suggest that they exert lower foot pressure under the medial part of their midfoot. However, human feet, and the human medial longitudinal arch, differ in that the anterior part of the foot is medially twisted on the posterior part of the foot, so that all the toes may contact the ground at the same time, and the twisting is so marked that the most medial toe, the big toe or hallux, (in some individuals the second toe) tends to exert the greatest propulsive force in walking and running. This gives the human foot an 'everted' or relatively outward-facing appearance compared to that of other apes. The strong twisting of the anterior part of the human foot on the posterior part tends to increase the height of the medial longitudinal arch. However, there is now considerable evidence that shoe-wearing also accentuates the height of the medial longitudinal arch and that the height of the medial longitudinal arch also differs very considerably between individuals and at different speeds. It is not yet agreed to what extent the early human ancestor Australopithecus afarensis
Australopithecus afarensis
Australopithecus afarensis is an extinct hominid that lived between 3.9 and 2.9 million years ago. A. afarensis was slenderly built, like the younger Australopithecus africanus. It is thought that A...
, (3.75 million years ago onwards) had acquired a functionally human-like foot, but the medial twist of the forefoot evident in fossil footbones of this species, and in the Laetoli
Laetoli
Laetoli is a site in Tanzania, dated to the Plio-Pleistocene and famous for its hominin footprints, preserved in volcanic ash . The site of the Laetoli footprints is located 45 km south of Olduvai gorge.-Date:...
footprint trail in Tanzania generally attributed to this species, certainly appears less marked than is evident in fossil footbones of Homo erectus
Homo erectus
Homo erectus is an extinct species of hominid that lived from the end of the Pliocene epoch to the later Pleistocene, about . The species originated in Africa and spread as far as India, China and Java. There is still disagreement on the subject of the classification, ancestry, and progeny of H...
(sometimes called Homo georgicus
Homo georgicus
Homo georgicus is a species of Homo that was suggested in 2002 to describe fossil skulls and jaws found in Dmanisi, Georgia in 1999 and 2001, which seem intermediate between Homo habilis and H. erectus. A partial skeleton was discovered in 2001. The fossils are about 1.8 million years old...
) from Dmanisi
Dmanisi
Dmanisi is a townlet and archaeological site in Kvemo Kartli region of Georgia approximately 93 km southwest of the nation’s capital Tbilisi in the river valley of Mashavera.- History :...
, Georgia (c. 1. 8 million years ago) and the roughly contemporaneous fossil footprint trail at Ileret
Ileret
Ileret is a village in Marsabit District, Eastern Province, Kenya. It is located in Northern Kenya, on the eastern shore of Lake Turkana, north of Sibiloi National Park and near the Ethiopian border. Administratively, Ileret is a part of a ward of the same name, which is part of North Horr...
, Kenya attributed to Homo erectus ergaster.
See also
- Foot typeFoot typeFoot type refers to differences in foot structure and shape, as reflected in pronation during heel strike running.Foot type affects the reduction of impact on the foot while walking, jogging, or running...
- Pes cavusPes cavusHigh arch is a human foot type in which the sole of the foot is distinctly hollow when bearing weight. That is, there is a fixed plantar flexion of the foot...
- Flat feetFlat feetFlat feet is a formal reference to a medical condition in which the arch of the foot collapses, with the entire sole of the foot coming into complete or near-complete contact with the ground...
- Arch supportArch supportAn arch support is a piece of material designed to provide support for the arch of the foot. An arch support may be placed on top of the shoe's insole, or may be part of the insole....
- Foot gymnasticsFoot gymnasticsFoot gymnastics are games and exercises intended to strengthen the muscles of legs and feet, improve the motion sequences of walking and sports, support therapy of varicose veins and dorsal pain...
