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
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
The iliopsoas refers to the joined psoas and the iliacus muscles. The two muscles are separate in the abdomen, but merge in the thigh; as such, they are given the common name iliopsoas. The iliopsoas muscle joins to the femur at the lesser trochanter, acts as the strongest flexor of the hip; the iliopsoas muscle is supplied by parts of the femoral nerve. The iliopsoas muscle is a composite muscle formed from the psoas major muscle, the iliacus muscle; the psoas major originates along the outer surfaces of the vertebral bodies of T12 and L1-L3 and their associated intervertebral discs. The iliacus originates in the iliac fossa of the pelvis; the psoas major unites with the iliacus at the level of the inguinal ligament and crosses the hip joint to insert on the lesser trochanter of the femur. The iliopsoas is classified as an "anterior hip muscle" or "inner hip muscle"; the psoas minor does contribute to the iliopsoas muscle. The inferior portion below the inguinal ligament forms part of the floor of the femoral triangle.
The psoas major is innervated by direct branches of the anterior rami off the lumbar plexus at the levels of L1-L3, while the iliacus is innervated by the femoral nerve. The iliopsoas is the prime mover of hip flexion, is the strongest of the hip flexors; the iliopsoas is important for standing and running. The iliacus and psoas major perform different actions; the iliopsoas muscle is covered by the iliac fascia, which begins as a strong tube-shaped psoas fascia, which surround the psoas major muscle as it passes under the medial arcuate ligament. Together with the iliac fascia, it continues down to the inguinal ligament where it forms the iliopectineal arch which separates the muscular and vascular lacunae, it is a typical posture muscle dominated by slow-twitch red type 1 fibers. Since it originates from the lumbar vertebrae and discs and inserts onto the femur, any structure from the lumbar spine to the femur can be affected directly. A short and tight iliopsoas presents as externally rotated legs and feet.
It can cause pain in the low or mid back, SI joint, groin, knee, or any combination. The iliopsoas gets innervation from the L2-4 nerve roots of the lumbar plexus which send branches to the superficial lumbar muscles; the femoral nerve passes through the muscle and innervates the quadriceps and sartorius muscles. It comprises the intermediate femoral cutaneous and medial femoral cutaneous nerves which are responsible for sensation over the anterior and medial aspects of the thigh, medial shin, arch of the foot nerves; the obturator nerve passes through the muscle, responsible for the sensory innervation of the skin of the medial aspect of the thigh and motor innervation of the adductor muscles of the lower extremity and sometimes the pectineus. Any of these innervated structures can be affected. Psoas abscess Iliopsoas tendonitis Muscles of the hip Muscles/Iliopsoas at exrx.net Cross section image: pelvis/pelvis-e12-15—Plastination Laboratory at the Medical University of Vienna
In anatomy, the saphenous opening is an oval opening in the upper mid part of the fascia lata of the thigh. It lateral to the pubic tubercle and is about 3 cm long and 1.5 cm wide. Just inferolateral to the pubic tubercle the fascia extends downwards forming an arched margin of the lateral boundary of the opening, it is covered by a thin perforated part of the superficial fascia called the fascia cribrosa, pierced by the great saphenous vein, the 3 superficial branches of the femoral artery, lymphatics. It transmits the great saphenous vein and other smaller vessels including the superficial epigastric artery and superficial external pudendal artery, as well as the femoral branch of the genitofemoral nerve; the fascia cribrosa, pierced by the structures passing through the opening, closes the aperture and must be removed to expose it
Internal obturator muscle
The internal obturator muscle or obturator internus muscle originates on the medial surface of the obturator membrane, the ischium near the membrane, the rim of the pubis. It exits the pelvic cavity through the lesser sciatic foramen; the internal obturator is situated within the lesser pelvis, at the back of the hip-joint. It functions to help laterally rotate femur with hip extension and abduct femur with hip flexion, as well as to steady the femoral head in the acetabulum, it arises from the inner surface of the antero-lateral wall of the pelvis, where it surrounds the greater part of the obturator foramen, being attached to the inferior pubic ramus and ischium, at the side to the inner surface of the hip bone below and behind the pelvic brim, reaching from the upper part of the greater sciatic foramen above and behind to the obturator foramen below and in front. It arises from the pelvic surface of the obturator membrane except in the posterior part, from the tendinous arch which completes the canal for the passage of the obturator vessels and nerve, to a slight extent from the obturator fascia, which covers the muscle.
The fibers converge toward the lesser sciatic foramen, end in four or five tendinous bands, which are found on the deep surface of the muscle. The tendon inserts on the greater trochanter of the proximal femur; the internal obturator muscle is innervated by the nerve to internal obturator. This bony surface is covered by smooth cartilage, separated from the tendon by a bursa, presents one or more ridges corresponding with the furrows between the tendinous bands; these bands leave the pelvis through the lesser sciatic foramen and unite into a single flattened tendon, which passes horizontally across the capsule of the hip-joint, after receiving the attachments of the superior and inferior gemellus muscles, is inserted into the forepart of the medial surface of the greater trochanter above the trochanteric fossa. A bursa and elongated in form, is found between the tendon and the capsule of the hip-joint; this article incorporates text in the public domain from page 477 of the 20th edition of Gray's Anatomy Anatomy photo:13:st-0407 at the SUNY Downstate Medical Center - "Gluteal Region: Muscles" Anatomy photo:43:st-0603 at the SUNY Downstate Medical Center - "The Female Pelvis: Muscles" Cross section image: pelvis/pelvis-e12-15—Plastination Laboratory at the Medical University of Vienna pelvis at The Anatomy Lesson by Wesley Norman perineum at The Anatomy Lesson by Wesley Norman Int.
J. Morphol. 25:95-98, 2007
The piriformis is a muscle in the gluteal region of the lower limbs. It is one of the six muscles in the lateral rotator group, it was first named by Adriaan van den Spiegel, a professor from the University of Padua in the 16th century. The piriformis muscle originates from the anterior part of the sacrum, the part of the spine in the gluteal region, from the superior margin of the greater sciatic notch, it exits the pelvis through the greater sciatic foramen to insert on the greater trochanter of the femur. Its tendon joins with the tendons of the superior gemellus, inferior gemellus, obturator internus muscles prior to insertion; the piriformis is a flat muscle, pyramidal in shape, lying parallel with the posterior margin of the gluteus medius. It is situated within the pelvis against its posterior wall, at the back of the hip-joint, it arises from the front of the sacrum by three fleshy digitations, attached to the portions of bone between the first, second and fourth anterior sacral foramina, to the grooves leading from the foramina: a few fibers arise from the margin of the greater sciatic foramen, from the anterior surface of the sacrotuberous ligament.
The muscle passes out of the pelvis through the greater sciatic foramen, the upper part of which it fills, is inserted by a rounded tendon into the upper border of the greater trochanter behind, but partly blended with, the common tendon of the obturator internus and superior and inferior gemellus muscles. In 17 % of people, the piriformis muscle is pierced by all of the sciatic nerve. Several variations occur, but the most common type of anomaly is the Beaton's type B, when the common peroneal nerve pierces the piriformis muscle, it may be united with the gluteus medius, send fibers to the gluteus minimus, or receive fibers from the superior gemellus. It may have two sacral attachments; the piriformis muscle is part of the lateral rotators of the hip, along with the quadratus femoris, gemellus inferior, gemellus superior, obturator externus, obturator internus. The piriformis laterally rotates the femur with hip extension and abducts the femur with hip flexion. Abduction of the flexed thigh is important in the action of walking because it shifts the body weight to the opposite side of the foot being lifted, which prevents falling.
The action of the lateral rotators can be understood by crossing the legs to rest an ankle on the knee of the other leg. This causes the femur to point the knee laterally; the lateral rotators oppose medial rotation by the gluteus medius and gluteus minimus. When the hip is flexed to 90 degrees, piriformis abducts the femur at the hip and reverses primary function, internally rotating the hip when the hip is flexed at 90 degrees or more. Piriformis syndrome occurs when the piriformis irritates the sciatic nerve, which comes into the gluteal region beneath the muscle, causing pain in the buttocks and referred pain along the sciatic nerve; this referred. Seventeen percent of the population has their sciatic nerve coursing through the piriformis muscle; this subgroup of the population is predisposed to developing sciatica. Sciatica can be described by pain, tingling, or numbness deep in the buttocks and along the sciatic nerve. Sitting down, climbing stairs, performing squats increases pain. Diagnosing the syndrome is based on symptoms and on the physical exam.
More testing, including MRIs, X-rays, nerve conduction tests can be administered to exclude other possible diseases. If diagnosed with piriformis syndrome, the first treatment involves progressive stretching exercises, massage therapy and physical treatment. Corticosteroids can be injected into the piriformis muscle. Findings suggest the possibility that Botulinum toxin type B may be of potential benefit in the treatment of pain attributed to piriformis syndrome. A more invasive, but sometimes necessary treatment involves surgical exploration. Surgery should always be a last resort; the piriformis is a important landmark in the gluteal region. As it travels through the greater sciatic foramen, it divides it into an inferior and superior part; this determines the name of the vessels and nerves in this region – the nerve and vessels that emerge superior to the piriformis are the superior gluteal nerve and superior gluteal vessels. Inferiorly, it is the same, the sciatic nerve travels inferiorly to the piriformis.
This article incorporates text in the public domain from page 476 of the 20th edition of Gray's Anatomy "Piriformis" University of Washington Anatomy photo:13:st-0408 at the SUNY Downstate Medical Center - "Gluteal Region: Muscles" Anatomy photo:43:15-0101 at the SUNY Downstate Medical Center - "The Female Pelvis: The Posterolateral Pelvic Wall"
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