The gluteus minimus, the smallest of the three gluteal muscles, is situated beneath the gluteus medius. It 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. It is a local stabilizer for the hip. A bursa is interposed between the greater trochanter. Between the gluteus medius and gluteus minimus are the deep branches of the superior gluteal vessels and the superior gluteal nerve; the deep surface of the gluteus minimus is in relation with the reflected tendon of the rectus femoris and the capsule of the hip joint. The gluteus medius and gluteus minimus abduct the thigh, when the limb is extended, are principally called into action in supporting the body on one limb, in conjunction with the tensor fasciæ latæ.
Their anterior fibers flex the hip, by drawing the greater trochanter forward, rotate the thigh inward, in which action they are assisted by the Tensor fasciæ latæ. Additionally, with the hip flexed, the gluteus minimus internally rotate the thigh. With the hip extended, the gluteus gluteus minimus externally rotate the thigh; the attachment to the superior capsule of the hip may serve to retract the capsule away from the joint during motion. This mechanism may prevent capsular impingement similar to the role of the articularis genus in the knee; the muscle may be divided into an anterior and a posterior part, or it may send slips to the piriformis, the superior gemellus or the outer part of the origin of the vastus lateralis. Paralysis of this muscle or gluteus medius, such as may be caused by the superior gluteal nerve palsy, can lead to difficulty abducting the leg. Patients will compensate for their difficulty walking by adopting a Trendelenburg gait; this article incorporates text in the public domain from page 475 of the 20th edition of Gray's Anatomy PTCentral Anatomy photo:13:st-0406 at the SUNY Downstate Medical Center
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 iliacus is a flat, triangular muscle which fills the iliac fossa. It forms the lateral portion of iliopsoas, providing flexion of the thigh and lower limb at the acetabulofemoral joint; the iliacus arises from the iliac fossa on the interior side of the hip bone, from the region of the anterior inferior iliac spine. It joins the psoas major to form the Iliopsoas as which it proceeds across the iliopubic eminence through the muscular lacuna to its insertion on the lesser trochanter of the femur, its fibers are inserted in front of those of the psoas major and extend distally over the lesser trochanter. The iliopsoas is innervated by direct branches from the lumbar plexus. In open-chain exercises, as part of the iliopsoas, the iliacus is important for lifting the femur forward. In closed-chain exercises, the iliopsoas bends the trunk forward and can lift the trunk from a lying posture because the psoas major crosses several vertebral joints and the sacroiliac joint. From its origin in the lesser pelvis the iliacus acts on the hip joint.
Platzer, Werner. Color Atlas of Human Anatomy, Vol. 1: Locomotor System. Thieme. ISBN 3-13-533305-1. Thieme Atlas of Anatomy: General Anatomy and Musculoskeletal System. Thieme. 2006. ISBN 1-58890-419-9. PTCentral Anatomy figure: 40:07-05 at Human Anatomy Online, SUNY Downstate Medical Center - "Muscles and nerves of the posterior abdominal wall." Pelvis at The Anatomy Lesson by Wesley Norman
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"
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
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 inguinal ligament is a band running from the pubic tubercle to the anterior superior iliac spine. It forms the base of the inguinal canal; the inguinal ligament runs from the anterior superior iliac crest of the ilium to the pubic tubercle of the pubic bone. It is formed by the external abdominal oblique aponeurosis and is continuous with the fascia lata of the thigh. There is some dispute over the attachments. Structures that pass deep to the inguinal ligament include: Psoas major, pectineus Femoral nerve and vein Lateral cutaneous nerve of thigh Lymphatics The ligament serves to contain soft tissues as they course anteriorly from the trunk to the lower extremity; this structure demarcates the superior border of the femoral triangle. It demarcates the inferior border of the inguinal triangle; the midpoint of the inguinal ligament, halfway between the anterior superior iliac spine and pubic tubercle, is the landmark for the femoral nerve. The mid-inguinal point, halfway between the anterior superior iliac spine and the pubic symphysis, is the landmark for the femoral artery.
It is referred to as Poupart's ligament, because François Poupart gave it relevance in relation to hernial repair, calling it "the suspender of the abdomen". It is sometimes termed the Fallopian ligament. Colles' ligament is reflex ligament not inguinal ligament. Pelvis Anatomy figure: 12:03-02 at Human Anatomy Online, SUNY Downstate Medical Center - "Deep muscles of the anterior thigh." Anatomy photo:35:os-0107 at the SUNY Downstate Medical Center - "Anterior Abdominal Wall: Osteology and Surface Anatomy " Anatomy photo:35:08-0100 at the SUNY Downstate Medical Center - "Anterior Abdominal Wall: The Inguinal Ligament" Anatomy image:7179 at the SUNY Downstate Medical Center Anatomy image:7431 at the SUNY Downstate Medical Center Diagram at gensurg.co.uk