Flexor hallucis longus muscle
The flexor hallucis longus muscle 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 tibialis posterior. All three muscles are innervated by the tibial nerve; the flexor hallucis. It arises from the inferior two-thirds of the posterior surface of the body of the fibula, with the exception of 2.5 cm. at its lowest part. The fibers pass obliquely downward and backward, where it passes through the tarsal tunnel on the medial side of the foot and end in a tendon which occupies nearly the whole length of the posterior surface of the muscle; this tendon lies in a groove which crosses the posterior surface of the lower end of the tibia, between the medial and lateral tubercles of the posterior surface of the talus, the under surface of the sustentaculum tali of the calcaneus. The grooves on the talus and calcaneus, which contain the tendon of the muscle, are converted by tendinous fibers into distinct canals, lined by a mucous sheath.
As the tendon passes forward in the sole of the foot, it is situated above, crosses from the lateral to the medial side of the tendon of the flexor digitorum longus, to which it is connected by a fibrous slip. A slip runs to the flexor digitorum and an additional slip runs from the flexor digitorum to the flexor hallucis. Peroneocalcaneus internus, arises below or outside the flexor hallucis from the back of the fibula, passes over the sustentaculum tali with the flexor hallucis and inserts into the calcaneum. Similar to the flexor digitorum longus and tibialis posterior muscles, the flexor hallucis longus muscle functions to plantar flex and invert the foot. However, it is unique in that it functions to flex the great toe and helps supinate the ankle. Common injuries associated with the FHL tendon are tenosynovitis and muscle strains; because the FHL muscle is small, injuries associated with this muscle and its tendon are overlooked. An MRI can be used to evaluate the condition of the FHL tendon.
Tears and areas of impingement can be found using this method. A diagnostic ultrasound can be used to diagnose FHL injuries, as it shows the muscle in movement and potential areas of impingement. Conservatively, an FHL injury can be evaluated by determining if movements caused by the FHL muscle cause pain along the inner ankle or under the big toe. After passing through the tarsal tunnel, the flexor hallucis longus tendon must curve around a bony landmark called the sustenaculum tali. Friction at this site is to cause pain on the posteromedial aspect of the ankle. While referred to as "dancer's tendinitis," FHL tendinitis occurs in ballet dancers and runners. Due to their excessive use of toe flexion, which results in ten times their body weight being applied to this small muscle and tendon and irritation is common at the site of the sustenaculum tali. Hallux saltans is a condition. With this condition, a nodule develops along the FHL tendon which may produce a popping effect during contraction because it drags along surrounding tissues.
If left untreated and continually irritated, stenosis of the tendon may occur, resulting in the big toe becoming stiff and immobile. This condition is known as Hallux Rigidus. Most FHL injuries can be managed through conservative treatment. Rest is the first indicated intervention for minor FHL injuries. Ice and ultrasound therapy can help with the inflammation and pain. Physical therapy exercises and stretches can help rehabilitate the muscle and tendon and address biomechanical errors that cause the inflammation and microtears in the tendon; some FHL injuries can be treated through rest, physical therapy and anti-inflammatory medication. However, more serious or chronic injuries may require surgery. If surgery is indicated, tears in the FHL will be repaired, debris will be removed from the area, it is worth noting that an os trigonum may cause similar symptoms to the ones caused by FHL tendinitis or tenosynovitis. A radiograph should be taken to rule out this condition; this article incorporates text in the public domain from page 485 of the 20th edition of Gray's Anatomy Anatomy photo:15:st-0404 at the SUNY Downstate Medical Center PTCentral
Squatting is a posture where the weight of the body is on the feet but the knees and hips are bent. In contrast sitting involves taking the weight of the body, at least in part, on the buttocks against the ground or a horizontal object such as a chair seat; the angle between the legs when squatting can vary from zero to splayed out, flexibility permitting. Another variable may be the degree of forward tilt of the upper body from the hips – see here and here. Squatting may be either: full – known as full squat, deep squat, on one's haunches, on one's hunkers, or hunkering – see text and see image gallery partial – known as partial, half, parallel, intermediate, incomplete or monkey squat etc. – see text and see image gallery. Crouching is considered to be synonymous with squatting, it is common to kneel with the other leg. One or both heels may be up when squatting. Young children instinctively squat. Among Chinese, Southeast Asian and Eastern European adults, squatting takes the place of sitting or standing.
Elements of squatting are used in everyday life without us realising it, whenever we lower our body. The variations in this section apply to full squatting but can apply to or have elements of partial squatting. Squatting for both legs can involve: heels down for both feet heels up for both feet, or the heel up for just one foot. Heels down squatting for both feet is the most stable arrangement of the three but most Western adults cannot do it. Where the heel is up for one foot, the thigh for that leg is more parallel to the ground than the other leg, additionally the heel up foot is planted further back than the heel down foot. Where the heel is up for both feet, it can be by different degrees thus giving two different thigh angles, it is common for one leg to be kneeling, while the other leg is: squatting with the heel down, or squatting with the heel up. Genuflection requires the heel down version of the squat/kneel combination; the kneel in the squat/kneel combination is just taking the heel up for one foot variant of both legs squatting a stage further.
The heel up squat version of the squat/kneel combination is a stage before both legs kneeling. Variations are possible as to which part of the toes touch the ground for a kneeling leg: the tip the under part the upper part; as a verb – early 15th century. Squatting in the sense of "crouch on the heels" is from the Old French words esquatir and escatir. Squatting in the sense of "compress, press down, lay flat, crush" is from about 1400. Meaning "posture of one who squats" is from 1570s. Act of squatting is from 1580s. Weight-lifting sense is from 1954. Young children squat instinctively as a continuous movement from standing up whenever they want to lower themselves to ground level. One- and two-year-olds can be seen playing in a stable squatting position, with feet wide apart and bottom not quite touching the floor, although at first they need to hold onto something to stand up again. Full squatting involves resting one's weight on the feet with the buttocks resting on the backs of the calves, it may be used as a posture for resting or working at ground level where the ground is too dirty or wet to sit or kneel.
Most Western adults cannot place their heels flat on the ground when squatting because of shortened Achilles tendons caused by habitually: sitting on chairs or seats wearing shoes with heels For this reason the squatting position is not sustainable for them for more than a few minutes as heels-up squatting is a less stable position than heels-down squatting. See dorsiflexion. Catchers in baseball and wicket-keepers in cricket facing slow deliveries assume full squatting positions. Australian wicket-keeper Sammy Carter was the first to squat on his haunches rather than bend over from the waist. Gopnik is a pejorative term to describe a particular subculture in Russia, the former Soviet republics, other East Slavic countries. Gopniks are seen squatting in groups, it is described as a learned behavior attributed to Russian prison culture. Gopniks wear Adidas tracksuits, due to them being popularised by the 1980 Moscow Olympics Soviet team; the Slav squat or Russian squat is associated with Gopniks in Eastern European countries together with stereotypical Eastern European behavior such as consumption of vodka and cigarettes and participation in street gambling.
It is a full squat with both heels down. Equivalents to the Slav squat in Western culture, sometimes with the hands together in a prayer position, are the rap squat, prison pose, jail pose, they are used as photographic poses. "Hunkerin'" is, in particular, the name applied to the American fad of resting in the squatting position in the late 1950s. Life referred to it as "sociable squatting"; such behavior had been seen in many cultures in Asia, for centuries when it became a fad in the United States in 1959. While the word "hunkerin'" is believed to originate from the Scots word for "haunches", claims were made for Yorkshire and Japan. Time reported that the craze started at the University of Arkansas when a shortage of chairs at a fraternity house led students to imitate their Ozark forefathers, who hunkered regularly; the fad spread first to Missouri and Oklahoma across the U. S. While males were the predominant hunkerers, it was reported that females were welcomed by many groups. Within months, re
The tarsus is a cluster of seven articulating bones in each foot situated between the lower end of tibia and fibula of the lower leg and the metatarsus. It is made up of the hindfoot; the tarsus articulates with the bones of the metatarsus, which in turn articulate with the proximal phalanges of the toes. The joint between the tibia and fibula above and the tarsus below is referred to as the ankle joint. In humans the largest bone in the tarsus is the calcaneus, the weight-bearing bone within the heel of the foot; the talus bone or ankle bone is connected superiorly to the two bones of the lower leg, the tibia and fibula, to form the ankle joint or talocrural joint. Together, the talus and calcaneus form the hindfoot; the five irregular bones of the midfoot—the cuboid and three cuneiform bones—form the arches of the foot which serves as a shock absorber. The midfoot is connected to the hind - and forefoot by the plantar fascia; the complex motion of the subtalar joint occurs in three planes and produces subtalar inversion and eversion.
Along with the transverse tarsal joint, the subtalar joint transforms tibial rotation into forefoot supination and pronation. The axis of rotation in the joint is directed upward 42 degrees from the horizontal plane and 16 degrees medially from the midline of the foot. However, the subtalar facets form a screw or Archimedean spiral, right-handed in the right foot, about which subtalar motion occurs. So, during subtalar inversion, the calcaneus rotates clockwise and translates forward along the axis of the screw. Average subtalar motion is 5-10 degrees eversion. Functional motion during the gait cycle is 10-15 degrees; the talonavicular and calcaneocuboid joints form the so-called transverse tarsal joint or Chopart's joint. It has two axes of motion. Inversion and eversion occur about a longitudinal axis oriented 15 degrees upward from the horizontal plane and 9 degrees medially from the longitudinal axis of the foot. Flexion and extension occur about an oblique axis oriented 52 degrees upward from the horizontal plane and 57 degrees anteromedially.
In vitro talonavicular motion is 17 degrees pronation-supination. The motions of the subtalar and transverse talar joints interact to make the foot either flexible or rigid. With the subtalar joint in eversion, the two joints of the transverse joint are parallel, which make movements in this joint possible. With the subtalar joint in inversion, the axes of the transverse joint are convergent, movements in this joint are thus locked and the midfoot rigid. In primitive tetrapods, such as Trematops, the tarsus consists of three rows of bones. There are three proximal tarsals, the tibiale and fibulare, named for their points of articulation with the bones of the lower limb; these are followed by a second row of four bones, referred to as the centralia, a row of five distal tarsals, each articulating with a single metatarsal. In the great majority of tetrapods, including all of those alive today, this simple pattern is modified by the loss and fusion of some of the bones. In reptiles and mammals, there are just two proximal tarsals, the calcaneus and the talus.
In mammals, including humans, the talus forms a hinge joint with the tibia, a feature well developed in the artiodactyls. The calcaneus is modified, forming a heel for the attachment of the Achilles tendon. Neither of these adaptations is found in reptiles, which have a simple structure to both bones; the fifth distal tarsal disappears early in evolution, with the remainder becoming the cuneiform and cuboid bones. Reptiles retain two centralia, while mammals have only one. In birds, the tarsus has disappeared, with the proximal tarsals having fused with the tibia, the centralia having disappeared, the distal bones having fused with the metatarsals to form a single tarsometatarsus bone giving the leg a third segment. Arches of the foot Carpus Cuboid syndrome Tarsal tunnel Tarsal tunnel syndrome Nordin, Margareta. Basic biomechanics of the musculoskeletal system. Lippincott Williams & Wilkins. ISBN 0-683-30247-7. "Anatomy of the foot and ankle". Podiatry Channel. Retrieved 30 August 2009. Romer, Alfred Sherwood.
The Vertebrate Body. Philadelphia, PA: Holt-Saunders International. Pp. 205–208. ISBN 0-03-910284-X. Diagram, identifying bones xrayslowerlimb at The Anatomy Lesson by Wesley Norman
Plantar calcaneonavicular ligament
The plantar calcaneonavicular ligament is a complex of three ligaments on the underside of the foot that connect the calcaneus with the navicular bone. The plantar calcaneonavicular ligamentous complex is a broad and thick band with three constituent ligaments that connect the anterior margin of the sustentaculum tali of the calcaneus to the plantar surface of the navicular, its individual components are the superomedial and lateral ligaments, which fan out and attach to the navicular bone at three separate locations. This ligamentous complex not only serves to connect the calcaneus and navicular, but supports the head of the talus, forming part of the articular cavity in which it is received, it helps to maintain the medial longitudinal arch of the foot, by providing support to the head of the talus, bears most of the body weight in a functioning foot. When torn, it can result in a flatfoot deformity, impair mobility; the dorsal or superomedial component of the ligament presents a fibrocartilaginous facet, lined by the synovial membrane, upon which a portion of the head of the talus rests.
Its plantar surface, consisting of the intermedial and lateral ligaments, is supported by the tendon of the tibialis posterior. Long plantar ligament Short plantar ligament This article incorporates text in the public domain from page 355 of the 20th edition of Gray's Anatomy lljoints at The Anatomy Lesson by Wesley Norman http://www.ithaca.edu/faculty/lahr/LE2000/ankle%20pics/5medankle-new.jpg
Mongolia is a landlocked country in East Asia. Its area is equivalent with the historical territory of Outer Mongolia, that term is sometimes used to refer to the current state, it is sandwiched between China to Russia to the north. Mongolia does not share a border with Kazakhstan. At 1,564,116 square kilometres, Mongolia is the 18th-largest and the most sparsely populated sovereign state in the world, with a population of around three million people, it is the world's second-largest landlocked country behind Kazakhstan and the largest landlocked country that does not border a closed sea. The country contains little arable land, as much of its area is covered by grassy steppe, with mountains to the north and west and the Gobi Desert to the south. Ulaanbaatar, the capital and largest city, is home to about 45% of the country's population. Ulaanbaatar shares the rank of the world's coldest capital city with Moscow and Nur-Sultan. 30% of the population is nomadic or semi-nomadic. The majority of its population are Buddhists.
The non-religious population is the second largest group. Islam is the dominant religion among ethnic Kazakhs; the majority of the state's citizens are of Mongol ethnicity, although Kazakhs and other minorities live in the country in the west. Mongolia joined the World Trade Organization in 1997 and seeks to expand its participation in regional economic and trade groups; the area of what is now Mongolia has been ruled by various nomadic empires, including the Xiongnu, the Xianbei, the Rouran, the Turkic Khaganate, others. In 1206, Genghis Khan founded the Mongol Empire, which became the largest contiguous land empire in history, his grandson Kublai Khan conquered China to establish the Yuan dynasty. After the collapse of the Yuan, the Mongols retreated to Mongolia and resumed their earlier pattern of factional conflict, except during the era of Dayan Khan and Tumen Zasagt Khan. In the 16th century, Tibetan Buddhism began to spread in Mongolia, being further led by the Manchu-founded Qing dynasty, which absorbed the country in the 17th century.
By the early 1900s one-third of the adult male population were Buddhist monks. After the collapse of the Qing dynasty in 1911, Mongolia declared independence, achieved actual independence from the Republic of China in 1921. Shortly thereafter, the country came under the control of the Soviet Union, which had aided its independence from China. In 1924, the Mongolian People's Republic was founded as a socialist state. After the anti-Communist revolutions of 1989, Mongolia conducted its own peaceful democratic revolution in early 1990; this led to a multi-party system, a new constitution of 1992, transition to a market economy. Homo erectus inhabited Mongolia from 850,000 years ago. Modern humans reached Mongolia 40,000 years ago during the Upper Paleolithic; the Khoit Tsenkher Cave in Khovd Province shows lively pink and red ochre paintings of mammoths, bactrian camels, ostriches, earning it the nickname "the Lascaux of Mongolia". The venus figurines of Mal'ta testify to the level of Upper Paleolithic art in northern Mongolia.
Neolithic agricultural settlements, such as those at Norovlin, Tamsagbulag and Rashaan Khad, predated the introduction of horse-riding nomadism, a pivotal event in the history of Mongolia which became the dominant culture. Horse-riding nomadism has been documented by archeological evidence in Mongolia during the Copper and Bronze Age Afanasevo culture; the wheeled vehicles found in the burials of the Afanasevans have been dated to before 2200 BC. Pastoral nomadism and metalworking became more developed with the Okunev culture, Andronovo culture and Karasuk culture, culminating with the Iron Age Xiongnu Empire in 209 BC. Monuments of the pre-Xiongnu Bronze Age include deer stones, keregsur kurgans, square slab tombs, rock paintings. Although cultivation of crops has continued since the Neolithic, agriculture has always remained small in scale compared to pastoral nomadism. Agriculture arose independently in the region; the population during the Copper Age has been described as mongoloid in the east of what is now Mongolia, as europoid in the west.
Tocharians and Scythians inhabited western Mongolia during the Bronze Age. The mummy of a Scythian warrior, believed to be about 2,500 years old, was a 30- to 40-year-old man with blond hair; as equine nomadism was introduced into Mongolia, the political center of the Eurasian Steppe shifted to Mongolia, where it remained until the 18th century CE. The intrusions of northern pastoralists into China during the Shang dynasty and Zhou dynasty presaged the age of nomadic empires; the concept of Mongolia as an independent power north of China is expressed in a letter sent by Emperor Wen of Han to Laoshang Chanyu in 162 BC: Since prehistoric times, Mongolia has been inhabited by nomads who, from time to time, formed great confederations that rose to power and prominence. Common institutions were the office of the Khan, the Kurultai and right wings, imperial army and the decimal military system; the first of these empires, the Xiongnu of undetermined
The talocalcaneonavicular joint is a ball and socket joint: the rounded head of the talus being received into the concavity formed by the posterior surface of the navicular, the anterior articular surface of the calcaneus, the upper surface of the plantar calcaneonavicular ligament. There are two ligaments in this joint: the dorsal talonavicular; this article incorporates text in the public domain from page 353 of the 20th edition of Gray's Anatomy
Cartilage is a resilient and smooth elastic tissue, a rubber-like padding that covers and protects the ends of long bones at the joints, is a structural component of the rib cage, the ear, the nose, the bronchial tubes, the intervertebral discs, many other body components. It is not as hard and rigid as bone; the matrix of cartilage is made up of glycosaminoglycans, collagen fibers and, elastin. Because of its rigidity, cartilage serves the purpose of holding tubes open in the body. Examples include the rings such as the cricoid cartilage and carina. Cartilage is composed of specialized cells called chondrocytes that produce a large amount of collagenous extracellular matrix, abundant ground substance, rich in proteoglycan and elastin fibers. Cartilage is classified in three types, elastic cartilage, hyaline cartilage and fibrocartilage, which differ in relative amounts of collagen and proteoglycan. Cartilage does not contain blood nerves. Nutrition is supplied to the chondrocytes by diffusion.
The compression of the articular cartilage or flexion of the elastic cartilage generates fluid flow, which assists diffusion of nutrients to the chondrocytes. Compared to other connective tissues, cartilage has a slow turnover of its extracellular matrix and does not repair. In embryogenesis, the skeletal system is derived from the mesoderm germ layer. Chondrification is the process by which cartilage is formed from condensed mesenchyme tissue, which differentiates into chondroblasts and begins secreting the molecules that form the extracellular matrix. Following the initial chondrification that occurs during embryogenesis, cartilage growth consists of the maturing of immature cartilage to a more mature state; the division of cells within cartilage occurs slowly, thus growth in cartilage is not based on an increase in size or mass of the cartilage itself. The articular cartilage function is dependent on the molecular composition of the extracellular matrix; the ECM consists of proteoglycan and collagens.
The main proteoglycan in cartilage is aggrecan, which, as its name suggests, forms large aggregates with hyaluronan. These aggregates hold water in the tissue; the collagen collagen type II, constrains the proteoglycans. The ECM responds to compressive forces that are experienced by the cartilage. Cartilage growth thus refers to the matrix deposition, but can refer to both the growth and remodeling of the extracellular matrix. Due to the great stress on the patellofemoral joint during resisted knee extension, the articular cartilage of the patella is among the thickest in the human body; the mechanical properties of articular cartilage in load-bearing joints such as the knee and hip have been studied extensively at macro and nano-scales. These mechanical properties include the response of cartilage in frictional, compressive and tensile loading. Cartilage displays viscoelastic properties. Lubricin, a glycoprotein abundant in cartilage and synovial fluid, plays a major role in bio-lubrication and wear protection of cartilage.
Cartilage has limited repair capabilities: Because chondrocytes are bound in lacunae, they cannot migrate to damaged areas. Therefore, cartilage damage is difficult to heal; because hyaline cartilage does not have a blood supply, the deposition of new matrix is slow. Damaged hyaline cartilage is replaced by fibrocartilage scar tissue. Over the last years and scientists have elaborated a series of cartilage repair procedures that help to postpone the need for joint replacement. Bioengineering techniques are being developed to generate new cartilage, using a cellular "scaffolding" material and cultured cells to grow artificial cartilage. Several diseases can affect cartilage. Chondrodystrophies are a group of diseases, characterized by the disturbance of growth and subsequent ossification of cartilage; some common diseases that affect the cartilage are listed below. Osteoarthritis: Osteoarthritis is a disease of the whole joint, however one of the most affected tissues is the articular cartilage.
The cartilage covering bones is thinned completely wearing away, resulting in a "bone against bone" within the joint, leading to reduced motion, pain. Osteoarthritis affects the joints exposed to high stress and is therefore considered the result of "wear and tear" rather than a true disease, it is treated by arthroplasty, the replacement of the joint by a synthetic joint made of a stainless steel alloy and ultra high molecular weight polyethylene. Chondroitin sulfate or glucosamine sulfate supplements, have been claimed to reduce the symptoms of osteoarthritis but there is little good evidence to support this claim. Traumatic rupture or detachment: The cartilage in the knee is damaged but can be repaired through knee cartilage replacement therapy; when athletes talk of damaged "cartilage" in their knee, they are referring to a damaged meniscus and not the articular cartilage. Achondroplasia: Reduced proliferation of chondrocytes in the epiphyseal plate of long bones during infancy and childhood, resulting in dwarfism.
Costochondritis: Inflammation of cartilage in the ribs, causing chest pain. Spinal disc herniation: Asymmetrical compression of an intervertebral disc ruptures the sac-like disc, causing a herniation of its soft content; the hernia compresses the adjacent nerves and causes back pain. Relapsing polychondritis: a destruction aut