In human anatomy, the thigh is the area between the hip and the knee. Anatomically, it is part of the lower limb; the single bone in the thigh is called the femur. This bone is thick and strong, forms a ball and socket joint at the hip, a modified hinge joint at the knee; the femur is the only bone in the thigh and serves for an attachment site for all muscles in the thigh. The head of the femur articulates with the acetabulum in the pelvic bone forming the hip joint, while the distal part of the femur articulates with the tibia and kneecap forming the knee. By most measures the femur is the strongest bone in the body; the femur is the longest bone in the body. The femur is categorised as a long bone and comprises a diaphysis, the shaft and two epiphysis or extremities that articulate with adjacent bones in the hip and knee. In cross-section, the thigh is divided up into three separate compartments, divided by fascia, each containing muscles; these compartments use the femur as an axis, are separated by tough connective tissue membranes.
Each of these compartments has its own blood and nerve supply, contains a different group of muscles. Medial fascial compartment of thigh, adductor Posterior fascial compartment of thigh, hamstring Anterior fascial compartment of thigh, extensionAnterior compartment muscles of the thigh include sartorius, the four muscles that comprise the quadriceps muscles- rectus femoris, vastus medialis, vastus intermedius and vastus lateralis. Posterior compartment muscles of the thigh are the hamstring muscles, which include semimembranosus and biceps femoris. Medial compartment muscles are pectineus, adductor magnus, adductor longus and adductor brevis, gracilis; because the major muscles of the thigh are the largest muscles of the body, resistance exercises of them stimulate blood flow more than any other localized activity. The arterial supply is by the obturator artery; the lymphatic drainage follows the arterial supply and drains to the lumbar lymphatic trunks on the corresponding side, which in turn drains to the cisterna chyli.
The deep venous system of the thigh consists of the femoral vein, the proximal part of the popliteal vein, various smaller vessels. The venae perfortantes connect the deep and the superficial system, which consists of the saphenous veins. Thigh weakness can result in a positive Gowers' sign on physical examination; the thigh meat of some animals such as chicken and cow is consumed as a food in many parts of the world
Vastus intermedius muscle
The vastus intermedius arises from the front and lateral surfaces of the body of the femur in its upper two-thirds, sitting under the rectus femoris muscle and from the lower part of the lateral intermuscular septum. Its fibers end in a superficial aponeurosis, which forms the deep part of the quadriceps femoris tendon; the vastus medialis and vastus intermedius appear to be inseparably united, but when the rectus femoris has been reflected during dissection a narrow interval will be observed extending upward from the medial border of the patella between the two muscles, the separation may be continued as far as the lower part of the intertrochanteric line, however, the two muscles are continuous. Due to being the deeper middle-most of the quadriceps muscle group, the intermedius is the most difficult to stretch once maximum knee flexion is attained, it cannot be further stretched by hip extension as the rectus femoris can, nor is it accessible to manipulate with massage therapy to stretch the fibres sideways as the vastus lateralis and vastus medialis are.
This article incorporates text in the public domain from page 471 of the 20th edition of Gray's Anatomy 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
Anatomical terms of muscle
Muscles are described using unique anatomical terminology according to their actions and structure. There are three types of muscle tissue in the human body: skeletal and cardiac. Skeletal striated muscle, or "voluntary muscle" joins to bone with tendons. Skeletal muscle maintains posture. Smooth muscle tissue is found in parts of the body; the majority of this type of muscle tissue is found in the digestive and urinary systems where it acts by propelling forward food and feces in the former and urine in the latter. Other places smooth muscle can be found are within the uterus, where it helps facilitate birth, the eye, where the pupillary sphincter controls pupil size. Cardiac muscle is specific to the heart, it is involuntary in its movement, is additionally self-excitatory, contracting without outside stimuli. As well as anatomical terms of motion, which describe the motion made by a muscle, unique terminology is used to describe the action of a set of muscles. Agonist muscles and antagonist muscles refer to muscles that inhibit a movement.
Agonist muscles cause a movement to occur through their own activation. For example, the triceps brachii contracts, producing a shortening contraction, during the up phase of a push-up. During the down phase of a push-up, the same triceps brachii controls elbow flexion while producing a lengthening contraction, it is still the agonist, because while resisting gravity during relaxing, the triceps brachii continues to be the prime mover, or controller, of the joint action. Agonists are interchangeably referred to as "prime movers," since they are the muscles considered responsible for generating or controlling a specific movement. Another example is the dumbbell curl at the elbow; the "elbow flexor" group is the agonist. During the lowering phase the "elbow flexor" muscles lengthen, remaining the agonists because they are controlling the load and the movement. For both the lifting and lowering phase, the "elbow extensor" muscles are the antagonists, they shorten during the dumbbell lowering phase.
Here it is important to understand that it is common practice to give a name to a muscle group based on the joint action they produce during a shortening contraction. However, this naming convention does not mean; this term describes the function of skeletal muscles. Antagonist muscles are the muscles that produce an opposing joint torque to the agonist muscles; this torque can aid in controlling a motion. The opposing torque can slow movement down - in the case of a ballistic movement. For example, during a rapid discrete movement of the elbow, such as throwing a dart, the triceps muscles will be activated briefly and to accelerate the extension movement at the elbow, followed immediately by a "burst" of activation to the elbow flexor muscles that decelerates the elbow movement to arrive at a quick stop. To use an automotive analogy, this would be similar to pressing your gas pedal and immediately pressing the brake. Antagonism is not an intrinsic property of a particular muscle group. During slower joint actions that involve gravity, just as with the agonist muscle, the antagonist muscle can shorten and lengthen.
Using the example above of the triceps brachii during a push-up, the elbow flexor muscles are the antagonists at the elbow during both the up phase and down phase of the movement. During the dumbbell curl, the elbow extensors are the antagonists for both the lifting and lowering phases. Antagonist and agonist muscles occur in pairs, called antagonistic pairs; as one muscle contracts, the other relaxes. An example of an antagonistic pair is the triceps. "Reverse motions" need antagonistic pairs located in opposite sides of a joint or bone, including abductor-adductor pairs and flexor-extensor pairs. These consist of an extensor muscle, which "opens" the joint and a flexor muscle, which does the opposite by decreasing the angle between two bones. However, muscles don't always work this way. Sometimes during a joint action controlled by an agonist muscle, the antagonist will be activated, naturally; this occurs and is not considered to be a problem unless it is excessive or uncontrolled and disturbs the control of the joint action.
This serves to mechanically stiffen the joint. Not all muscles are paired in this way. An example of an exception is the deltoid. Synergist muscles help perform, the same set of joint motion as the agonists. Synergists muscles act on movable joints. Synergists are sometimes referred to as "neutralizers" because they help cancel out, or neutralize, extra motion from the agonists to make sure that the force generated works within the desired plane of motion. Muscle fibers can only contract up to 40% of their stretched length, thus the short fibers of pennate muscles are more suitable where power rather than range of contraction is required. This limitation in the range of contraction affects all muscles, those that act over several joints may be unable to shorten sufficiently to produce
Anatomical terms of motion
Motion, the process of movement, is described using specific anatomical terms. Motion includes movement of organs, joints and specific sections of the body; the terminology used describes this motion according to its direction relative to the anatomical position of the joints. Anatomists use a unified set of terms to describe most of the movements, although other, more specialized terms are necessary for describing the uniqueness of the movements such as those of the hands and eyes. In general, motion is classified according to the anatomical plane. Flexion and extension are examples of angular motions, in which two axes of a joint are brought closer together or moved further apart. Rotational motion may occur at other joints, for example the shoulder, are described as internal or external. Other terms, such as elevation and depression, describe movement above or below the horizontal plane. Many anatomical terms derive from Latin terms with the same meaning. Motions are classified after the anatomical planes they occur in, although movement is more than not a combination of different motions occurring in several planes.
Motions can be split into categories relating to the nature of the joints involved: Gliding motions occur between flat surfaces, such as in the intervertebral discs or between the carpal and metacarpal bones of the hand. Angular motions occur over synovial joints and causes them to either increase or decrease angles between bones. Rotational motions move a structure in a rotational motion along a longitudinal axis, such as turning the head to look to either side. Apart from this motions can be divided into: Linear motions, which move in a line between two points. Rectilinear motion is motion in a straight line between two points, whereas curvilinear motion is motion following a curved path. Angular motions occur when an object is around another object decreasing the angle; the different parts of the object do not move the same distance. Examples include a movement of the knee, where the lower leg changes angle compared to the femur, or movements of the ankle; the study of movement is known as kinesiology.
A categoric list of movements of the human body and the muscles involved can be found at list of movements of the human body. The prefix hyper- is sometimes added to describe movement beyond the normal limits, such as in hypermobility, hyperflexion or hyperextension; the range of motion describes the total range of motion. For example, if a part of the body such as a joint is overstretched or "bent backwards" because of exaggerated extension motion it can be described as hyperextended. Hyperextension increases the stress on the ligaments of a joint, is not always because of a voluntary movement, it may be other causes of trauma. It may be used in surgery, such as in temporarily dislocating joints for surgical procedures; these are general terms. Most terms have a clear opposite, so are treated in pairs. Flexion and extension describe movements; these terms come from the Latin words with the same meaning. Flexion describes a bending movement that decreases the angle between a segment and its proximal segment.
For example, bending the elbow, or clenching a hand into a fist, are examples of flexion. When sitting down, the knees are flexed; when a joint can move forward and backward, such as the neck and trunk, flexion refers to movement in the anterior direction. When the chin is against the chest, the head is flexed, the trunk is flexed when a person leans forward. Flexion of the shoulder or hip refers to movement of the leg forward. Extension is the opposite of flexion, describing a straightening movement that increases the angle between body parts. For example, when standing up, the knees are extended; when a joint can move forward and backward, such as the neck and trunk, extension refers to movement in the posterior direction. Extension of the hip or shoulder moves the leg backward. Abduction is the motion of a structure away from the midline while adduction refer to motion towards the center of the body; the centre of the body is defined as the midsagittal plane. These terms come from Latin words with similar meanings, ab- being the Latin prefix indicating "away," ad- indicating "toward," and ducere meaning "to draw or pull".
Abduction refers to a motion that pulls a part away from the midline of the body. In the case of fingers and toes, it refers to spreading the digits apart, away from the centerline of the hand or foot. Abduction of the wrist is called radial deviation. For example, raising the arms up, such as when tightrope-walking, is an example of abduction at the shoulder; when the legs are splayed at the hip, such as when doing a star jump or doing a split, the legs are abducted at the hip. Adduction refers to a motion that pulls a structure or part toward the midline of the body, or towards the midline of a limb. In the case of fingers and toes, it refers to bringing the digits together, towards the centerline of the hand or foot. Adduction of the wrist is called ulnar deviation. Dropping the arms to the sides, bringing the knees together, are examples of adduction. Ulnar deviation is the hand moving towards the ulnar styloid. Radial deviation is the hand moving towards the radial styloid; the terms elevation and depression refer to movement below the horizontal.
They derive from the Latin terms with similar meaningsElevation refers to movement in a superior direction. For example
Rectus femoris muscle
The rectus femoris muscle is one of the four quadriceps muscles of the human body. The others are the vastus medialis, the vastus intermedius, the vastus lateralis. All four parts of the quadriceps muscle attach to the patella by the quadriceps tendon; the rectus femoris is situated in the middle of the front of the thigh. Its functions are to extend the leg at the knee joint, it arises by two tendons: the anterior or straight, from the anterior inferior iliac spine. The two unite at an acute angle and spread into an aponeurosis, prolonged downward on the anterior surface of the muscle, from this the muscular fibers arise; the muscle ends in a broad and thick aponeurosis that occupies the lower two-thirds of its posterior surface, becoming narrowed into a flattened tendon, is inserted into the base of the patella. The neurons for voluntary thigh contraction originate near the summit of the medial side of the precentral gyrus; these neurons send a nerve signal, carried by the corticospinal tract down the brainstem and spinal cord.
The signal starts with the upper motor neurons carrying the signal from the precentral gyrus down through the internal capsule, through the cerebral peduncle, into the medulla. In the medullary pyramid, the corticospinal tract decussates and becomes the lateral corticospinal tract; the nerve signal will continue down the lateral corticospinal tract until it reaches spinal nerve L4. At this point, the nerve signal will synapse from the upper motor neurons to the lower motor neurons; the signal will travel through the anterior root of L4 and into the anterior rami of the L4 nerve, leaving the spinal cord through the lumbar plexus. The posterior division of the L4 root is the Femoral nerve; the femoral nerve innervates the quadriceps femoris, a fourth of, the rectus femoris. When the rectus femoris receives the signal that has traveled all the way from the medial side of the precentral gyrus, it contracts, extending the knee and flexing the thigh at the hip; the rectus femoris and iliopsoas are the flexors of the thigh at the hip.
The rectus femoris is a weaker hip flexor when the knee is extended because it is shortened and thus suffers from active insufficiency. The rectus femoris is not dominant in knee extension when the hip is flexed since it is shortened and thus suffers from active insufficiency. In essence: the action of extending the knee from a seated position is driven by the vastus lateralis, vastus medialis, vastus intermedius, less by the rectus femoris. In the other extreme, the muscle's ability to flex the hip and extend the knee can be compromised in a position of full hip extension and knee flexion, due to passive insufficiency; the rectus femoris is a direct antagonist at the hip and at the knee. Rectus femoris strain, referred to as hip flexor strain, is an injury at the tendon that attaches to the patella or in the muscle itself; the injury is a partial tear but could be a full tear. The injury is caused by a forceful movement related to sprinting, jumping, or kicking and is common in sports like football or soccer.
The rectus femoris is prone to injury since it crosses both the hip. Symptoms include a sudden sharp pain at the front of the hip or in the groin and bruising, an inability to contract the rectus femoris with a full tear; this article incorporates text in the public domain from page 470 of the 20th edition of Gray's Anatomy PTCentral
The trochanter is an anatomical portion of the femur near its joint with the hip bone. In humans and most mammals the trochanters serve as important muscle attachment sites. Humans are known to have three trochanters, though the anatomic "normal" includes only the greater and lesser trochanters.'Trokhos' ='wheel', with reference to the spherical femoral head, first named'trokhanter'. Usage came to include the femoral neck. In human anatomy, the trochanter is a part of the femur, it can refer to: Greater trochanter Lesser trochanter Third trochanter Fourth trochanter, of archosaur leg bones trochanter, a segment of the arthropod leg Intertrochanteric crest Intertrochanteric line