The gracilis muscle is the most superficial muscle on the medial side of the thigh. It is thin and flattened, broad above and tapering below, it arises by a thin aponeurosis from the anterior margins of the lower half of the symphysis pubis and the upper half of the pubic arch. The muscle's fibers run vertically downward; this tendon passes behind the medial condyle of the femur, curves around the medial condyle of the tibia where it becomes flattened, inserts into the upper part of the medial surface of the body of the tibia, below the condyle. For this reason, the muscle is a lower limb adductor. At its insertion the tendon is situated above that of the semitendinosus muscle, its upper edge is overlapped by the tendon of the sartorius muscle, which it joins to form the pes anserinus; the pes anserinus is separated from the medial collateral ligament of the knee-joint by a bursa. A few of the fibers of the lower part of the tendon are prolonged into the deep fascia of the leg. By its inner or superficial surface gracilis is in relation with the fascia lata, below with the sartorius and internal saphenous nerve.
By its outer or deep surface with the adductor longus and magnus, the internal lateral ligament of the knee-joint, from which it is separated by a synovial bursa common to the tendons of the gracilis and semitendinosus. The obturator nerve innervates the gracilis muscle via the lumbar spinal vertebrae; the muscle adducts, medially rotates, laterally rotates, flexes the hip as above, aids in flexion of the knee. The gracilis muscle is used as a flap in microsurgery. According to the classification of Mathes and Nahai, it presents a type II blood supply, allowing it to be transferred on its artery derived from the medial circumflex femoral artery; this artery enters the muscle about 10 cm from the pubic symphysis. At this point the nerve enters. Gracilis muscle is used in reconstructive surgery, either as a pedicled flap or as a free microsurgical flap. Both pedicled and free flaps can be musculocutaneos; as a pedicled flap, gracilis muscle can be used in perineal and vaginal reconstruction, after oncological surgery, in the treatment of recurrent anovaginal and rectovaginal fistulas as well in the coverage of the neurovascular bundle after vascular surgery.
As a functioning pedicled flap, the gracilis muscle can be transferred for the treatment of anal incontinence. This technique called graciloplasty was described in the 1950s by Pickrell and was revolutionized in the late 1980s by the introduction of chronic muscle electro-stimulation; the gracilis microsurgical free flap is used in the reconstruction of upper and lower limbs, in breast reconstruction and – as a free functioning flap – to restore forearm function or in dynamic reconstruction of facial paralysis. Gracilis Muscles Clinical Role The muscle may be split to reduce bulk for facial reanimation, as well as to repair hand muscles, it can be used to fashion an external anal sphincter. This article incorporates text in the public domain from page 471 of the 20th edition of Gray's Anatomy Anatomy figure: 12:02-07 at Human Anatomy Online, SUNY Downstate Medical Center - "Muscles of the anterior compartment of the thigh." Anatomy figure: 14:02-02 at Human Anatomy Online, SUNY Downstate Medical Center - "Muscles that form the superficial boundaries of the popliteal fossa."
Cross section image: pembody/body18b—Plastination Laboratory at the Medical University of Vienna
Deep peroneal nerve
The deep peroneal nerve begins at the bifurcation of the common peroneal nerve between the fibula and upper part of the peroneus longus, passes infero-medially, deep to extensor digitorum longus, to the anterior surface of the interosseous membrane, comes into relation with the anterior tibial artery above the middle of the leg. Deep peroneal nerve is the nerve of the dorsum of the foot, it is one of the terminal branches of the common peroneal nerve. It corresponds to the posterior interosseus nerve of the forearm, it begins at the lateral side of the fibula bone, enters the anterior compartment by piercing the anterior intermuscular septum. It pierces the extensor digitorum longus and lies next to the anterior tibial artery, following the course of the artery until the ankle-joint where the nerve divides into medial and lateral terminal branches. In the leg, the deep peroneal nerve divides into several branches: Muscular branches - supplies four muscles in the leg: tibialis anterior, extensor hallucis longus, extensor digitorum longus, peroneous tertius Close to the ankle joint, deep peroneal nerve terminates by dividing into medial and lateral terminal branches.
Medial terminal branch - This nerve accompanies the dorsalis pedis artery along the dorsum of the foot, and, at the first interosseous space, divides into two dorsal digital nerves which supply the adjacent sides of the great and second toes, communicating with the medial dorsal cutaneous branch of the superficial peroneal nerve. Before it divides it gives off to the first space an interosseous branch which supplies the metatarsophalangeal joint of the great toe and sends a filament to the first Interosseous dorsalis muscle. Lateral terminal branch - This nerve passes across the tarsus, beneath the extensor digitorum brevis, supplies the extensor digitorum brevis; this nerve ends in a pseudoganglion deep to the extensor digitorum brevis. From the pseudoganglion, three minute branches are given off to supply the tarsal joints and the metatarsophalangeal joints of the second and fourth toes. In the leg, the deep peroneal nerve supplies muscular branches to the anterior compartment of extensor muscles in the leg which include the tibialis anterior, extensor digitorum longus, peroneus tertius, extensor hallucis longus, an articular branch to the ankle-joint.
After its bifurcation past the ankle joint, the lateral branch of the deep peroneal nerve innervates the extensor digitorum brevis and the extensor hallucis brevis, while the medial branch goes on to provide cutaneous innervation to the webbing between the first and second digits. Damage to the deep peroneal nerve, as is possible with traumatic injury to the lateral knee, results in foot drop; the deep peroneal nerve is subject to injury resulting from lower motor neuron disease, diabetes and infectious or inflammatory conditions. Injury to the common peroneal nerve is the most common isolated mononeuropathy of the lower extremity and produces sensory problems on the lateral lower leg in addition to foot drop; this article incorporates text in the public domain from page 965 of the 20th edition of Gray's Anatomy Anatomy photo:16:st-0601 at the SUNY Downstate Medical Center - "The Foot: Nerves"
Biceps femoris muscle
The biceps femoris is a muscle of the thigh located to the posterior, or back. As its name implies, it has two parts, it has two heads of origin: the long head arises from the lower and inner impression on the posterior part of the tuberosity of the ischium. This is a common tendon origin with the semitendinosus muscle, from the lower part of the sacrotuberous ligament; the short head, arises from the lateral lip of the linea aspera, between the adductor magnus and vastus lateralis extending up as high as the insertion of the gluteus maximus, from the lateral prolongation of the linea aspera to within 5 cm. of the lateral condyle. The two muscle unite in an intricate fashion; the fibers of the long head form a fusiform belly, which passes obliquely downward and lateralward across the sciatic nerve to end in an aponeurosis which covers the posterior surface of the muscle and receives the fibers of the short head. Inferiorly, the aponeurosis condenses to form a tendon which predominantly inserts onto the lateral side of the head of the fibula.
There is a second small insertional attachment by a small tendon slip into the lateral condyle of the tibia. At its insertion the tendon divides into two portions, which embrace the fibular collateral ligament of the knee-joint. Together, this joining of tendons is referred to as the conjoined tendon of the knee. From the posterior border of the tendon a thin expansion is given off to the fascia of the leg; the tendon of insertion of this muscle forms the lateral hamstring. The short head may be absent; the tendon of insertion may be attached to the Iliotibial band and to retinacular fibers of the lateral joint capsule. A slip may pass to the gastrocnemius, it is a composite muscle as the short head of the biceps femoris develops in the flexor compartment of the thigh and is thus innervated by common fibular branch of the sciatic nerve, while the long head is innervated by the tibial branch of the sciatic nerve. The muscle's vascular supply is derived from the anastomoses of several arteries: the perforating branches of the profunda femoris artery, the inferior gluteal artery, the popliteal artery.
Both heads of the biceps femoris perform knee flexion. Since the long head originates in the pelvis it is involved in hip extension; the long head of the biceps femoris is a weaker knee flexor. For the same reason the long head is a weaker hip extender; when the knee is semi-flexed, the biceps femoris in consequence of its oblique direction rotates the leg outward. Avulsion of the biceps femoris tendon is common in sports that require explosive bending of the knee as seen in sprinting; this article incorporates text in the public domain from page 478 of the 20th edition of Gray's Anatomy Kumakura, Hiroo. "Functional analysis of the biceps femoris muscle during locomotor behavior in some primates". American Journal of Physical Anthropology. 79: 379–391. Doi:10.1002/ajpa.1330790314. PMID 2504047. Marshall, John L.. "The Biceps Femoris Tendon and Its Functional Significance". J Bone Joint Surg Am. 54: 1444–1450. Sneath, R. S.. "The insertion of the biceps femoris". J. Anat. 89: 550–553. PMC 1244747. PMID 13278305.
UWash - long head UWash - short head Anatomy photo:14:06-0100 at the SUNY Downstate Medical Center Anatomy photo:14:st-0402 at the SUNY Downstate Medical Center
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
The pectineus muscle is a flat, quadrangular muscle, situated at the anterior part of the upper and medial aspect of the thigh. The pectineus muscle is the most anterior adductor of the hip; the muscle does adduct and medially rotate the thigh but its primary function is hip flexion. It can be classified in the anterior compartment of thigh; the pectineus muscle arises from the pectineal line of the pubis and to a slight extent from the surface of bone in front of it, between the iliopectineal eminence and pubic tubercle, from the fascia covering the anterior surface of the muscle. The pectineus is in relation by its anterior surface with the pubic portion of the fascia lata, which separates it from the femoral artery and vein and internal saphenous vein, lower down with the profunda artery. By its posterior surface with the capsule of the hip joint, with the obturator externus and adductor brevis, the obturator artery and vein being interposed. By its external border with the psoas major, the femoral artery resting upon the line of interval.
By its internal border with the outer edge of the adductor longus. Obturator foramen is situated directly behind this muscle, it forms part of the floor of the femoral triangle. The lumbar plexus is formed from the anterior rami of nerves L1 to L4 and some fibers from T12. With only five roots and two divisions, it is less complex than the brachial plexus and gives rise to a number of nerves including the femoral nerve and accessory obturator nerve; the pectineus muscle is considered a composite muscle as the innervation is by the femoral nerve and a branch of the obturator nerve called the accessory obturator nerve. When it is present, the accessory obturator nerve innervates a portion of the pectineus muscle, entering the muscle on its dorsomedial aspect; the greater nerve to the muscle is the femoral nerve. Unlike the obturator accessory nerve, the femoral nerve is always present and provides the sole innervation for the pectineus muscle in over 90% of cases; the muscle is innervated by the accessory obturator nerve in the 8.7% of cases in which the nerve occurs.
It is one of the muscles responsible for hip flexion. It adducts the thigh. Thigh This article incorporates text in the public domain from page 472 of the 20th edition of Gray's Anatomy Woodburne, Russell. "The Accessory Obturator Nerve and the Innervation of the Pectineus Muscle". Michigan Library Med School: 367–369. Retrieved 2 December 2015. Saladin, Kenneth S. Anatomy & Physiology: The Unity of Form and Function. New York, NY: McGraw-Hill, 2007. Pg.493. Print. Anatomy figure: 12:02-05 at Human Anatomy Online, SUNY Downstate Medical Center - "Muscles of the anterior compartment of the thigh." Anatomy figure: 12:03-04 at Human Anatomy Online, SUNY Downstate Medical Center - "Deep muscles of the anterior thigh." Cross section image: pelvis/pelvis-e12-15—Plastination Laboratory at the Medical University of Vienna
Anterior tibial artery
The anterior tibial artery of the leg carries blood to the anterior compartment of the leg and dorsal surface of the foot, from the popliteal artery. It is accompanied along its course, it crosses the anterior aspect of the ankle joint, at which point it becomes the dorsalis pedis artery. The artery originates at the distal end of the popliteus muscle posterior to the tibia; the artery passes anterior to the popliteus muscle prior to passing between the tibia and fibula through an oval opening at the superior aspect of the interosseus membrane. The artery descends between the tibialis anterior and extensor digitorum longus muscles; the branches of the anterior tibial artery are: posterior tibial recurrent artery anterior tibial recurrent artery muscular branches anterior medial malleolar artery anterior lateral malleolar artery dorsalis pedis artery As the artery passes medial to the fibular neck it becomes vulnerable to damage during a tibial osteotomy. Gray's s157 - The Arteries of the Lower Extremity Gray's s95 - Ankle joint Anatomy figure: 12:04-15 at Human Anatomy Online, SUNY Downstate Medical Center - "Arteries of the lower extremity shown in association with major landmarks."
Http://www.dartmouth.edu/~humananatomy/figures/chapter_15/15-10. HTM http://www.dartmouth.edu/~humananatomy/figures/chapter_17/17-3. HTM
External obturator muscle
The external obturator muscle, obturator externus muscle is a flat, triangular muscle, which covers the outer surface of the anterior wall of the pelvis. It is sometimes considered part of the medial compartment of thigh, sometimes considered part of the gluteal region, it arises from the margin of bone around the medial side of the obturator membrane and surrounding bone, viz. from the inferior pubic ramus, the ramus of the ischium. The fibers springing from the pubic arch extend on to the inner surface of the bone, where they obtain a narrow origin between the margin of the foramen and the attachment of the obturator membrane; the fibers converge and pass posterolateral and upward, end in a tendon which runs across the back of the neck of the femur and lower part of the capsule of the hip joint and is inserted into the trochanteric fossa of the femur. The obturator vessels lie between the obturator membrane. In 33 % of people a supernumerary muscle is found between the adductor minimus. While this muscle, when present, is similar to its neighbouring adductors, it is formed by separation from the superficial layer of the external obturator, is thus not ontogenetically related to the adductor muscles of the hip.
This muscle originates from the upper part of the inferior pubic ramus from where it runs downwards and laterally. In half of cases, it inserts into the anterior surface of the insertion aponeurosis of the adductor minimus. In the remaining cases, it is either inserted into the upper part of the pectineal line or the posterior part of the lesser trochanter, it has been demonstrated by the course of the posterior branch of obturator nerve that the obturator externus is divided into a superior muscle fascicle and a main belly. The supernumerary muscle described above originates from the superior fascicle, while an anomalous fascicle — derived from the external obturator — originates from the main belly; the "original" external obturator, i.e. without these supernumerary muscular parts occurs in only 20% of cases, the external obturator undergoes ontogenetic variations. The external obturator muscle acts as the lateral rotator of the hip joint; as a short muscle around the hip joint, it stabilizes the hip joint as a postural muscle.
This article incorporates text in the public domain from page 477 of the 20th edition of Gray's Anatomy Cross section image: pelvis/pelvis-e12-15—Plastination Laboratory at the Medical University of Vienna lljoints at The Anatomy Lesson by Wesley Norman PTCentral