Sartorius muscle
The sartorius muscle is the longest muscle in the human body. It is a long, superficial muscle that runs down the length of the thigh in the anterior compartment; the sartorius muscle originates from the anterior superior iliac spine and part of the notch between the anterior superior iliac spine and anterior inferior iliac spine. It runs obliquely across the anterior part of the thigh in an inferomedial direction, it passes behind the medial condyle of the femur to end in a tendon. This tendon curves anteriorly to join the tendons of the gracilis and semitendinosus muscles in the pes anserinus, where it inserts into the superomedial surface of the tibia, its upper portion forms the lateral border of the femoral triangle, the point where it crosses adductor longus marks the apex of the triangle. Deep to sartorius and its fascia is the adductor canal, through which the saphenous nerve, femoral artery and vein, nerve to vastus medialis pass. Like the other muscles in the anterior compartment of the thigh, sartorius is innervated by the femoral nerve.
It may originate from the outer end of the inguinal ligament, the notch of the ilium, the ilio-pectineal line or the pubis. The muscle may be split into two parts, one part may be inserted into the fascia lata, the femur, the ligament of the patella or the tendon of the semitendinosus; the tendon of insertion may end in the fascia lata, the capsule of the knee-joint, or the fascia of the leg. The muscle may be absent in some people; the sartorius muscle can move the hip joint and the knee joint, but all of its actions are weak, making it a synergist muscle. At the hip, it can flex, weakly abduct, laterally rotate the thigh. At the knee, it can flex the leg. Turning the foot to look at the sole or sitting cross-legged demonstrates all four actions of the sartorius. One of the many conditions that can disrupt the use of the sartorius is pes anserine bursitis, an inflammatory condition of the medial portion of the knee; this condition occurs in athletes from overuse and is characterized by pain and tenderness.
The pes anserinus is made up from the tendons of the gracilis and sartorius muscles. When inflammation of the bursa underlying the tendons occurs they separate from the head of the tibia. Sartorius comes from the Latin word sartor, meaning tailor, it is sometimes called the tailor's muscle; this name was chosen in reference to the cross-legged position. In French, the muscle name itself "couturier" comes from this specific position, referred to as "sitting as a tailor". There are other hypotheses as to the genesis of the name. One is that it refers to the location of the inferior portion of the muscle being the "inseam" or area of the inner thigh that tailors measure when fitting trousers. Another is that the muscle resembles a tailor's ribbon. Additionally, antique sewing machines required continuous cross body pedaling; this combination of lateral rotation and flexion of the hip and flexion of the knee gave tailors enlarged sartorius muscles. The sartorius is called the honeymoon muscle; this article incorporates text in the public domain from page 470 of the 20th edition of Gray's Anatomy Anatomy photo:14:st-0407 at the SUNY Downstate Medical Center Cross section image: pembody/body15a—Plastination Laboratory at the Medical University of Vienna Cross section image: pelvis/pelvis-e12-15—Plastination Laboratory at the Medical University of Vienna
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
Quadratus femoris muscle
The quadratus femoris is a flat, quadrilateral skeletal muscle. Located on the posterior side of the hip joint, it is a strong external rotator and adductor of the thigh, but acts to stabilize the femoral head in the acetabulum, it originates on the lateral border of the ischial tuberosity of the ischium of the pelvis. From there, it passes laterally to its insertion on the posterior side of the head of the femur: the quadrate tubercle on the intertrochanteric crest and along the quadrate line, the vertical line which runs downward to bisect the lesser trochanter on the medial side of the femur. Along its course, quadratus is aligned edge to edge with the inferior gemellus above and the adductor magnus below, so that its upper and lower borders run horizontal and parallel. At its origin, the upper margin of the adductor magnus is separated from it by the terminal branches of the medial femoral circumflex vessels. A bursa is found between the front of this muscle and the lesser trochanter. Sometimes absent.
Groin pain can be a disabling ailment with many potential root causes: one such cause overlooked, is quadratus femoris tendinitis. Magnetic resonance imaging can show abnormal signal intensity at the insertion of the right quadratus femoris tendon, which suggests inflammation of the area. Since the muscle works to laterally rotate and adduct the femur, actions involving the lower body can strain the muscle. In addition, patients present with hip pain and an increased signal intensity of the MRI of the quadratus femoris have been shown to have a narrower ischiofemoral space compared to the general populace; the ischiofemoral impingement may be a cause of the hip pain associated with quadratus femoris tendinitis. This article incorporates text in the public domain from page 477 of the 20th edition of Gray's Anatomy Mcminn, R. M. H.. Last's Applied. Elsevier Australia. ISBN 0-7295-3752-8. Platzer, Werner. Color Atlas of Human Anatomy, Vol 1: Locomotor system. Thieme. ISBN 3-13-533305-1. Thieme Atlas of Anatomy.
Thieme. 2006. ISBN 978-1-60406-062-1. PTCentral Anatomy photo:13:st-0409 at the SUNY Downstate Medical Center
Aponeurosis
An aponeurosis is a type or a variant of the deep fascia, in the form of a sheet of pearly-white fibrous tissue that attaches sheet-like muscles needing a wide area of attachment. Their primary function is to join muscles and the body parts they act upon, whether it be bone or other muscles, they have a shiny, whitish-silvery color, are histologically similar to tendons, are sparingly supplied with blood vessels and nerves. When dissected, aponeuroses are peel off by sections; the primary regions with thick aponeuroses are in the ventral abdominal region, the dorsal lumbar region, the ventriculus in birds, the palmar and plantar regions. The anterior abdominal aponeuroses are located just superficial to the rectus abdominis muscle, it has for its borders the external oblique, pectoralis muscles, the latissimus dorsi. The posterior lumbar aponeuroses are situated just on top of the epaxial muscles of the thorax, which are multifidus spinae and sacrospinalis; the palmar aponeuroses occur on the palms of the hands.
The extensor hoods are aponeuroses at the back of the fingers. The plantar aponeuroses occur on the plantar aspect of the foot, they extend from the calcaneal tuberosity diverge to connect to the bones and the dermis of the skin around the distal part of the metatarsal bones. The anterior and posterior intercostal membranes are aponeuroses located between the ribs and are continuations of the external and internal intercostal muscles, respectively; the epicranial aponeurosis, or galea aponeurotica, is a tough layer of dense fibrous tissue which runs from the frontalis muscle anteriorly to the occipitalis posteriorly. Pennate muscles, in which the muscle fibers are oriented at an angle to the line of action have two aponeuroses. Muscle fibers connect one to the other, each aponeurosis thins into a tendon which attaches to bone at the origin or insertion site. Like tendons, aponeuroses attached to pennate muscles can be stretched by the forces of muscular contraction, absorbing energy like a spring and returning it when they recoil to unloaded conditions.
Serving as an origin or insertion site for certain muscles e.g latissimus dorsi. Aponeurosis of the obliquus externus abdominis Aponeurosis of the serratus posterior superior muscle Plantar aponeurosis Inguinal aponeurotic falx Bicipital aponeurosis Palatine aponeurosis Fascia Gray's s104 - Aponeuroses
Public domain
The public domain consists of all the creative works to which no exclusive intellectual property rights apply. Those rights may have been forfeited, expressly waived, or may be inapplicable; the works of William Shakespeare and Beethoven, most early silent films, are in the public domain either by virtue of their having been created before copyright existed, or by their copyright term having expired. Some works are not covered by copyright, are therefore in the public domain—among them the formulae of Newtonian physics, cooking recipes, all computer software created prior to 1974. Other works are dedicated by their authors to the public domain; the term public domain is not applied to situations where the creator of a work retains residual rights, in which case use of the work is referred to as "under license" or "with permission". As rights vary by country and jurisdiction, a work may be subject to rights in one country and be in the public domain in another; some rights depend on registrations on a country-by-country basis, the absence of registration in a particular country, if required, gives rise to public-domain status for a work in that country.
The term public domain may be interchangeably used with other imprecise or undefined terms such as the "public sphere" or "commons", including concepts such as the "commons of the mind", the "intellectual commons", the "information commons". Although the term "domain" did not come into use until the mid-18th century, the concept "can be traced back to the ancient Roman Law, as a preset system included in the property right system." The Romans had a large proprietary rights system where they defined "many things that cannot be owned" as res nullius, res communes, res publicae and res universitatis. The term res nullius was defined as things not yet appropriated; the term res communes was defined as "things that could be enjoyed by mankind, such as air and ocean." The term res publicae referred to things that were shared by all citizens, the term res universitatis meant things that were owned by the municipalities of Rome. When looking at it from a historical perspective, one could say the construction of the idea of "public domain" sprouted from the concepts of res communes, res publicae, res universitatis in early Roman law.
When the first early copyright law was first established in Britain with the Statute of Anne in 1710, public domain did not appear. However, similar concepts were developed by French jurists in the 18th century. Instead of "public domain", they used terms such as publici juris or propriété publique to describe works that were not covered by copyright law; the phrase "fall in the public domain" can be traced to mid-19th century France to describe the end of copyright term. The French poet Alfred de Vigny equated the expiration of copyright with a work falling "into the sink hole of public domain" and if the public domain receives any attention from intellectual property lawyers it is still treated as little more than that, left when intellectual property rights, such as copyright and trademarks, expire or are abandoned. In this historical context Paul Torremans describes copyright as a, "little coral reef of private right jutting up from the ocean of the public domain." Copyright law differs by country, the American legal scholar Pamela Samuelson has described the public domain as being "different sizes at different times in different countries".
Definitions of the boundaries of the public domain in relation to copyright, or intellectual property more regard the public domain as a negative space. According to James Boyle this definition underlines common usage of the term public domain and equates the public domain to public property and works in copyright to private property. However, the usage of the term public domain can be more granular, including for example uses of works in copyright permitted by copyright exceptions; such a definition regards work in copyright as private property subject to fair-use rights and limitation on ownership. A conceptual definition comes from Lange, who focused on what the public domain should be: "it should be a place of sanctuary for individual creative expression, a sanctuary conferring affirmative protection against the forces of private appropriation that threatened such expression". Patterson and Lindberg described the public domain not as a "territory", but rather as a concept: "here are certain materials – the air we breathe, rain, life, thoughts, ideas, numbers – not subject to private ownership.
The materials that compose our cultural heritage must be free for all living to use no less than matter necessary for biological survival." The term public domain may be interchangeably used with other imprecise or undefined terms such as the "public sphere" or "commons", including concepts such as the "commons of the mind", the "intellectual commons", the "information commons". A public-domain book is a book with no copyright, a book, created without a license, or a book where its copyrights expired or have been forfeited. In most countries the term of protection of copyright lasts until January first, 70 years after the death of the latest living author; the longest copyright term is in Mexico, which has life plus 100 years for all deaths since July 1928. A notable exception is the United States, where every book and tale published prior to 1924 is in the public domain.
Vastus lateralis muscle
The vastus lateralis called the"vastus externus" is the largest and most powerful part of the quadriceps femoris, a muscle in the thigh. Together with other muscles of the quadriceps group, it serves to extend the knee joint, moving the lower leg forward, it arises from a series of flat, broad tendons attached to the femur, attaches to the outer border of the patella. It joins with the other muscles that make up the quadriceps in the quadriceps tendon, which travels over the knee to connect to the tibia; the vastus lateralis is the recommended site for intramuscular injection in infants less than 7 months old and those unable to walk, with loss of muscular tone. The vastus lateralis muscle arises from several areas of the femur, including the upper part of the intertrochanteric line; these form a broad flat tendon that covers the upper three-quarters of the muscle. From the inner surface of the aponeurosis, many muscle fibers originate; some additional fibers arise from the tendon of the gluteus maximus muscle, from the septum between the vastus lateralis and short head of the biceps femoris.
The fibers form a large fleshy mass, attached to a second strong aponeurosis, placed on the deep surface of the lower part of the muscle. This lower aponeurosis becomes contracted and thickened into a flat tendon that attaches to the outer border of the patella, subsequently joins with the quadriceps femoris tendon, expanding the capsule of the knee-joint; the vastus lateralis muscle is innervated by the muscular branches of the femoral nerve. Notes This article incorporates text in the public domain from page 470 of the 20th edition of Gray's Anatomy Cross section image: pembody/body18b—Plastination Laboratory at the Medical University of Vienna Cross section image: pelvis/pelvis-e12-15—Plastination Laboratory at the Medical University of Vienna PTCentral
Gluteal muscles
The gluteal muscles are a group of three muscles which make up the buttocks: the gluteus maximus, gluteus medius and gluteus minimus. The three muscles insert on the femur; the functions of the muscles include extension, external rotation and internal rotation of the hip joint. The gluteus maximus is the most superficial of the three gluteal muscles, it makes up a large portion of the appearance of the hips. It is a narrow and thick fleshy mass of a quadrilateral shape, forms the prominence of the nates; the gluteus medius is a broad, radiating muscle, situated on the outer surface of the pelvis. It lies profound to the gluteus maximus and its posterior third is covered by the gluteus maximus, its anterior two-thirds by the gluteal aponeurosis, which separates it from the superficial fascia and integument; the gluteus minimus is the smallest of the three gluteal muscles and is situated beneath the gluteus medius. The bulk of the gluteal muscle mass contributes only to shape of the buttocks; the other major contributing factor is that of the panniculus adiposus of the buttocks, well developed in this area, gives the buttock its characteristic rounded shape.
The gluteal muscle bulk and tone can be improved with exercise. However, it is predominantly the disposition of the overlying panniculus adiposus which may cause sagging in this region of the body. Exercise in general which can contribute to fat loss can lead to reduction of mass in subcutaneal fat storage locations on the body which includes the panniculus, so for leaner and more active individuals, the glutes will more predominantly contribute to the shape than someone less active with a fattier composition; the degree of body fat stored in various locations such as the panniculus is dictated by genetic and hormonal profiles. The gluteus maximus arises from the posterior gluteal line of the inner upper ilium, the rough portion of bone including the crest above and behind it; the fibers are lateralward. Its action is to extend and to laterally rotate the hip, to extend the trunk; the gluteus medius muscle originates on the outer surface of the ilium between the iliac crest and the posterior gluteal line above, the anterior gluteal line below.
The fibers of the muscle converge into a strong flattened tendon that inserts on the lateral surface of the greater trochanter. More the muscle's tendon inserts into an oblique ridge that runs downward and forward on the lateral surface of the greater trochanter; the gluteus minimus is fan-shaped, arising from the outer surface of the ilium, between the anterior and inferior gluteal lines, behind, from the margin of the greater sciatic notch. The fibers converge to the deep surface of a radiated aponeurosis, this ends in a tendon, inserted into an impression on the anterior border of the greater trochanter, gives an expansion to the capsule of the hip joint; the functions of muscles includes extension, lateral rotation and medial rotation of the hip joint. The gluteus maximus supports the extended knee through the iliotibial tract. Sitting for long periods can lead to the gluteal muscles atrophying through constant pressure and disuse; this may be associated with lower back pain, difficulty with some movements that require the gluteal muscles, such as rising from the seated position, climbing stairs.
Any exercise that works and/or stretches the buttocks is suitable, for example lunges, hip thrusts, climbing stairs, bicycling, squats, arabesque and various specific exercises for the bottom. Weight training exercises which are known to strengthen the gluteal muscles include the squat, leg press, any other movements involving external hip rotation and hip extension. Gluteal crease McMinn, RMH Last applied. London: Churchill Livingstone. ISBN 0-443-04662-X 8b; the Muscles and Fasciæ of the Thigh Bartleby.com, Henry Gray, Anatomy of the Human Body, 1918
