An interosseous membrane is a broad and thin plane of fibrous tissue that separates many of the bones of the body. It is an important component of many joints. Interosseous membranes in the human body: Interosseous membrane of forearm Interosseous membrane of leg Interosseous_membrane at the Duke University Health System's Orthopedics program Anatomy figure: 10:06-10 at Human Anatomy Online, SUNY Downstate Medical Center
A tendon or sinew is a tough band of fibrous connective tissue that connects muscle to bone and is capable of withstanding tension. Tendons are similar to ligaments. Ligaments join one bone to bone, while tendons connect muscle to bone for a proper functioning of the body. Histologically, tendons consist of dense regular connective tissue fascicles encased in dense irregular connective tissue sheaths. Normal healthy tendons are composed of parallel arrays of collagen fibers packed together, they are anchored to bone by Sharpey's fibres. The dry mass of normal tendons, which makes up about 30% of their total mass, is composed of about 86% collagen, 2% elastin, 1–5% proteoglycans, 0.2% inorganic components such as copper and calcium. The collagen portion is made up of 97–98% type I collagen, with small amounts of other types of collagen; these include type II collagen in the cartilaginous zones, type III collagen in the reticulin fibres of the vascular walls, type IX collagen, type IV collagen in the basement membranes of the capillaries, type V collagen in the vascular walls, type X collagen in the mineralized fibrocartilage near the interface with the bone.
Collagen fibres coalesce into macroaggregates. After secretion from the cell, the cleaved by procollagen N- and C-proteinases, the tropocollagen molecules spontaneously assemble into insoluble fibrils. A collagen molecule is about 300 nm long and 1–2 nm wide, the diameter of the fibrils that are formed can range from 50–500 nm. In tendons, the fibrils assemble further to form fascicles, which are about 10 mm in length with a diameter of 50–300 μm, into a tendon fibre with a diameter of 100–500 μm. Fascicles are bound by the endotendineum, a delicate loose connective tissue containing thin collagen fibrils. and elastic fibres. Groups of fascicles are bounded by the epitenon. Filling the interstitia within the fascia where the tendon is located is the paratenon a fatty areolar tissue; the collagen in tendons are held together with proteoglycan components including decorin and, in compressed regions of tendon, which are capable of binding to the collagen fibrils at specific locations. The proteoglycans are interwoven with the collagen fibrils – their glycosaminoglycan side chains have multiple interactions with the surface of the fibrils – showing that the proteoglycans are important structurally in the interconnection of the fibrils.
The major GAG components of the tendon are dermatan sulfate and chondroitin sulfate, which associate with collagen and are involved in the fibril assembly process during tendon development. Dermatan sulfate is thought to be responsible for forming associations between fibrils, while chondroitin sulfate is thought to be more involved with occupying volume between the fibrils to keep them separated and help withstand deformation; the dermatan sulfate side chains of decorin aggregate in solution, this behavior can assist with the assembly of the collagen fibrils. When decorin molecules are bound to a collagen fibril, their dermatan sulfate chains may extend and associate with other dermatan sulfate chains on decorin, bound to separate fibrils, therefore creating interfibrillar bridges and causing parallel alignment of the fibrils; the tenocytes produce the collagen molecules, which aggregate end-to-end and side-to-side to produce collagen fibrils. Fibril bundles are organized to form fibres with the elongated tenocytes packed between them.
There is a three-dimensional network of cell processes associated with collagen in the tendon. The cells communicate with each other through gap junctions, this signalling gives them the ability to detect and respond to mechanical loading. Blood vessels may be visualized within the endotendon running parallel to collagen fibres, with occasional branching transverse anastomoses; the internal tendon bulk is thought to contain no nerve fibres, but the epitenon and paratenon contain nerve endings, while Golgi tendon organs are present at the junction between tendon and muscle. Tendon length varies from person to person. Tendon length is, in practice, the deciding factor regarding potential muscle size. For example, all other relevant biological factors being equal, a man with a shorter tendons and a longer biceps muscle will have greater potential for muscle mass than a man with a longer tendon and a shorter muscle. Successful bodybuilders will have shorter tendons. Conversely, in sports requiring athletes to excel in actions such as running or jumping, it is beneficial to have longer than average Achilles tendon and a shorter calf muscle.
Tendon length is determined by genetic predisposition, has not been shown to either increase or decrease in response to environment, unlike muscles, which can be shortened by trauma, use imbalances and a lack of recovery and stretching. Traditionally, tendons have been considered to be a mechanism by which muscles connect to bone as well as muscles itself, functioning to transmit forces; this connection allows tendons to passively modulate forces during locomotion, providing additional stability with no active work. However, over the past two decades, much research focused on the elastic properties of some tendons and their ability to function as springs. Not all tendons are required to perform the same functional role, with some predominantly positioning limbs, such as the fingers when writing and others acting as springs to make locomotion more efficient. Energy storing tendons can recover energy at high efficiency. For example, during a human stride, the Achilles tendon stretches as the ankle joint dorsiflexes.
During the last portion of the stride, as the foot plantar-flexes (pointing the
Arches of the foot
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. They are categorized as transverse arches; the longitudinal arches of the foot can be divided into lateral arches. The medial arch is higher than the lateral longitudinal arch, it is made up by the calcaneus, the talus, the navicular, the three cuneiforms, the first and third metatarsals. Its summit is at the superior articular surface of the talus, 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 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 is the joint between the talus and navicular, but this portion is braced by the plantar calcaneonavicular ligament a.k.a. spring ligament, elastic and is thus able to restore the arch to its original condition when the disturbing force is removed.
The ligament is strengthened medially by blending with the deltoid ligament of the ankle joint, is supported inferiorly by the tendon of the Tibialis posterior, 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, flexor digitorum longus, flexor hallucis longus and by the ligaments of all the articulations involved; the lateral arch is composed of the calcaneus, the cuboid, the fourth and fifth metatarsals. Two notable 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. While these medial and lateral arches may be demonstrated as the component antero-posterior arches of the foot, the fundamental longitudinal arch is contributed to by both, consists of the calcaneus, third cuneiform, third metatarsal: all the other bones of the foot may be removed without destroying this 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 arch is composed of the three cuneiforms, the cuboid, the five metatarsal bases. The transverse arch is strengthened by the interosseous and dorsal ligaments, by the short muscles of the first and fifth toes, by the Peronæus longus, whose tendon stretches across between the piers of the arches; the medial longitudinal arch in particular creates a space for soft tissues with elastic properties, which act as springs the thick plantar aponeurosis, passing from the heel to the toes. Because of their elastic properties, these soft tissues can spread ground contact reaction forces over a longer time period, thus reduce the risk of musculoskeletal wear or damage, they can store the energy of these forces, returning it at the next step and thus reducing the cost of walking and running, where vertical forces are higher.
The anatomy and shape of a person’s longitudinal and transverse arch can dictate the types of injuries to which that person is susceptible. The height of a person’s arch is determined by the height of the navicular bone. Collapse of the longitudinal arches results in. A person with a low longitudinal arch, or flat feet will stand and walk with their feet in a pronated position, where the foot everts or rolls inward; this makes the person susceptible to arch pain and plantar fasciitis. Flat footed people may have more difficulty performing exercises that require supporting their weight on their toes. People who have high longitudinal arches or a cavus foot tend to walk and stand with their feet in a supinated position where the foot inverts or rolls outward. High arches can cause plantar fasciitis as they cause the plantar fascia to be stretched away from the calcaneus or heel bone. Additionally, high or low arches can increase the risk of shin splints as the anterior tibialis must work harder to keep the foot from slapping the ground.
The non-human apes tend to walk on the lateral side of the foot, with an'inverted' foot, which may reflect a basic adaptation to walking on branches. It is 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, 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, the twisting is so marked that the most medial toe, the big toe or hallux, tends
There are three cuneiform bones in the human foot: the first or medial cuneiform the second or intermediate cuneiform known as the middle cuneiform the third or lateral cuneiformThey are located between the navicular bone and the first and third metatarsal bones and are medial to the cuboid bone. There are three cuneiform bones: The medial cuneiform is the largest of the cuneiforms, it is situated at the medial side of the foot, anterior to the navicular bone and posterior to the base of the first metatarsal. Lateral to it is the intermediate cuneiform, it articulates with four bones: the navicular, second cuneiform, first and second metatarsals. The tibialis anterior and fibularis longus muscle inserts at the medial cuneiform bone; the intermediate cuneiform is shaped like the thin end pointing downwards. The intermediate cuneiform is situated between the other two cuneiform bones, articulates with the navicular posteriorly, the second metatarsal anteriorly and with the other cuneiforms on either side.
The lateral cuneiform intermediate in size between the other two cuneiform bones, is wedge-shaped, the base being uppermost. It occupies the center of the front row of the tarsal bones, between the intermediate cuneiform medially, the cuboid laterally, the navicular posteriorly and the third metatarsal in front; the tibialis posterior inserts at the medial cuneiform, while the flexor hallucis brevis originates from it
A malleolus is the bony prominence on each side of the human ankle. Each leg is supported by two bones, the tibia on the inner side of the leg and the fibula on the outer side of the leg; the medial malleolus is the prominence on the inner side of the ankle, formed by the lower end of the tibia. The lateral malleolus is the prominence on the outer side of ankle, formed by the lower end of the fibula; the word malleolus, plural malleoli, comes from Latin and means "small hammer". The medial malleolus is found at the foot end of the tibia; the medial surface of the lower extremity of tibia is prolonged downward to form a strong pyramidal process, flattened from without inward - the medial malleolus. The medial surface of this process is convex and subcutaneous; the lateral or articular surface is smooth and concave, articulates with the talus. The anterior border is rough, for the attachment of the anterior fibers of the deltoid ligament of the ankle-joint; the posterior border presents a broad groove, the malleolar sulcus, directed obliquely downward and medially, double.
The summit of the medial malleolus is marked by a rough depression behind, for the attachment of the deltoid ligament. The major structure that passes anterior to the medial mallelous is the saphenous vein. Structures that pass behind medial malleolus deep to the flexor retinaculum: Tibialis posterior tendon Flexor digitorum longus Posterior tibial artery Posterior tibial vein Tibial nerve Flexor hallucis longus The lateral malleolus is found at the foot end of the fibula, of a pyramidal form, somewhat flattened from side to side; the medial surface presents in front a smooth triangular surface, convex from above downward, which articulates with a corresponding surface on the lateral side of the talus. Behind and beneath the articular surface is a rough depression, which gives attachment to the posterior talofibular ligament; the lateral surface is convex and continuous with the triangular, subcutaneous surface on the lateral side of the body. The anterior border is thick and rough and marked below by a depression for the attachment of the anterior talofibular ligament.
The posterior border is broad and presents the shallow malleolar sulcus, for the passage of the tendons of the Peronæi longus and brevis. The summit gives attachment to the calcaneofibular ligament. A major structure, located between the lateral malleolus and the Achilles tendon is the sural nerve. A bimalleolar fracture is a fracture of the ankle that involves the lateral malleolus and the medial malleolus. Studies have shown that bimalleolar fractures are more common in women, people over 60 years of age, patients with existing comorbidities. A trimalleolar fracture is a fracture of the ankle that involves the lateral malleolus, the medial malleolus, the distal posterior aspect of the tibia, which can be termed the posterior malleolus; the trauma is sometimes accompanied by ligament dislocation. This article incorporates text in the public domain from page 5 of the 20th edition of Gray's Anatomy
Muscles of the hip
In human anatomy, the muscles of the hip joint are those muscles that cause movement in the hip. Most modern anatomists define 17 of these muscles, although some additional muscles may sometimes be considered; these are divided into four groups according to their orientation around the hip joint: the gluteal group. The muscles of the hip consist of four main groups The gluteal muscles include the gluteus maximus, gluteus medius, gluteus minimus, tensor fasciae latae, they cover the lateral surface of the ilium. The gluteus maximus, which forms most of the muscle of the buttocks, originates on the ilium and sacrum and inserts on the gluteal tuberosity of the femur as well as the iliotibial tract, a tract of strong fibrous tissue that runs along the lateral thigh to the tibia and fibula; the gluteus medius and gluteus minimus originate anterior to the gluteus maximus on the ilium and both insert on the greater trochanter of the femur. The tensor fasciae latae shares its origin with the gluteus maximus at the ilium and shares the insertion at the iliotibial tract.
The adductor brevis, adductor longus, adductor magnus and gracilis make up the adductor group. The adductors all originate on the pubis and insert on the medial, posterior surface of the femur, with the exception of the gracilis which inserts just below the medial condyle of the tibia; the iliacus and psoas major comprise the iliopsoas group. The psoas major is a large muscle that runs from the bodies and disc of the L1 to L5 vertebrae, joins with the iliacus via its tendon, connects to the lesser trochanter of the femur; the iliacus originates on the iliac fossa of the ilium. Together these muscles are referred to as the "iliopsoas"; this group consists of the externus and internus obturators, the piriformis, the superior and inferior gemelli, the quadratus femoris. These six originate at or below the acetabulum of the ilium and insert on or near the greater trochanter of the femur. Additional muscles, such as the rectus femoris and the sartorius, can cause some movement in the hip joint; however these muscles move the knee, not classified as muscles of the hip.
The hamstring muscles, which originate from the ischial tuberosity inserting on the tibia/fibula, have a large moment assisting with hip extension. Movements of the hip occur. Most muscles are responsible for more than one type of movement. Movements of the hip are described in anatomical terminology using anatomical terms of motion; the movement that brings the thighs close to the abdomen is called "flexion". When the legs open, such as in the lotus posture of yoga, this is called "lateral rotation", with the opposite movement called "medial rotation". Hip abduction occurs when the femur moves outward as in taking the thighs apart. Hip adduction occurs. Many muscles contribute to these movements: The psoas is the primary hip flexor, assisted by the iliacus; the pectineus, the adductors longus and magnus, as well as the tensor fasciae latae are involved in flexion. The gluteus maximus is the main hip extensor, but the inferior portion of the adductor magnus plays a role; the adductor group is responsible for hip adduction.
Medial rotation is performed by the gluteus medius and gluteus minimus, as well as the tensor fasciae latae and assisted by the adductors brevis and longus and the superior portion of the adductor magnus. Each muscle of the lateral rotator group causes lateral rotation of the thigh; these muscles are aided by the inferior portion of the adductor magnus. Hips muscles play a role in maintaining the standing posture; these muscles work in an integrated system with muscles of the shoulder, core, lower leg, supporting muscles of the spine, to provide the ability to stand with good posture. These muscles include the gluteus medius and gluteus minimus which abduct the thigh, prevent swaying of hips, stabilize pelvic region while keeping hips level, shift an individual’s weight in order to adjust body placement to increase one's overall body stability. Calais-Germain, Blandine. "Anatomy of Movement", Eastland Press, 1993. ISBN 0-939616-17-3 Martini, Frederic. "Human Anatomy", 3rd Edition, Prentice-Hall, 2000.
ISBN 0-13-010011-0 Marieb, Elaine. "Essentials of Human Anatomy and Physiology", 6th Edition. Addison Wesley Longman, 2000. ISBN 0-8053-4940-5 Netter, Frank H. "Atlas of Human Anatomy", 2nd Edition, Icon Learning Systems, 2001. ISBN 0-914168-81-9
Posterior tibial artery
The posterior tibial artery of the lower limb carries blood to the posterior compartment of the leg and plantar surface of the foot, from the popliteal artery via the tibial-fibular trunk. It is accompanied by the posterior tibial vein, along its course; the posterior tibial artery gives rise to the medial plantar artery, lateral plantar artery, gives rise to the fibular artery. The branch of the fibular artery is said to rise from the bifurcation of the tibial-fibular trunk and the posterior tibial artery. In addition a calcaneal branch to the medial aspect of the calcaneus; the posterior tibial artery pulse can be palpated halfway between the posterior border of the medial malleolus and the achilles tendon and is examined by physicians when assessing a patient for peripheral vascular disease. It is rarely absent in young and healthy individuals, it is palpated over Pimenta's Point. Gray's s157 - "The Arteries of the Lower Extremity" Gray's s95 - "Ankle joint" Anatomy figure: 12:04-14 at Human Anatomy Online, SUNY Downstate Medical Center - "Arteries of the lower extremity shown in association with major landmarks."
Image at umich.edu - pulse http://www.dartmouth.edu/~humananatomy/figures/chapter_15/15-10. HTM http://www.dartmouth.edu/~humananatomy/figures/chapter_17/17-3. HTM