Superior gluteal artery
The superior gluteal artery is the largest branch of the internal iliac artery, appears to be the continuation of the posterior division of that vessel. It is a short artery which runs backward between the lumbosacral trunk and the first sacral nerve, divides into a superficial and a deep branch after passing out of the pelvis above the upper border of the piriformis muscle. Within the pelvis, it gives off branches to the iliacus and obturator internus muscles. Just previous to exiting the pelvic cavity, it gives off a nutrient artery which enters the ilium; the superficial branch enters the deep surface of the gluteus maximus, divides into numerous branches, some of which supply the muscle and anastomose with the inferior gluteal artery, while others perforate its tendinous origin, supply the integument covering the posterior surface of the sacrum, anastomosing with the posterior branches of the lateral sacral arteries. The deep branch lies under the gluteus medius and immediately subdivides into the superior and inferior divisions.
The superior division continues the original course of the vessel, passingalong the upper border of the gluteus minimus to the anterior superior spine of the ilium, anastomosing with the deep iliac circumflex artery and the ascending branch of the lateral femoral circumflex artery. The inferior division crosses the gluteus minimus obliquely to the greater trochanter, distributing branches to the gluteal muscles and anastomoses with the lateral femoral circumflex artery; some branches pierce the gluteus supply the hip-joint. This artery takes part in the trochanteric anastomoses, forming a connection between internal iliac and femoral artery. Inferior gluteal artery This article incorporates text in the public domain from page 622 of the 20th edition of Gray's Anatomy Anatomy photo:43:13-0105 at the SUNY Downstate Medical Center - "The Female Pelvis: Branches of Internal Iliac Artery"
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
Superior gluteal nerve
The superior gluteal nerve is a nerve that originates in the pelvis and supplies the gluteus medius, the gluteus minimus, the tensor fasciae latae and the piriformis muscles. The superior gluteal nerve originates in the sacral plexus, it arises from the dorsal divisions of the L4, L5 and S1. It leaves the pelvis through the greater sciatic foramen above the piriformis, accompanied by the superior gluteal artery and the superior gluteal vein, it accompanies the upper branch of the deep division of the superior gluteal artery and ends in the gluteus minimus and tensor fasciae latae muscle. The superior nerve starts out in the pelvis and supplies the tensor fasciae latae, the gluteus minimus, the gluteus medius muscle In normal gait, the small gluteal muscles on the stance side can stabilize the pelvis in the coronal plane. Weakness or paralysis of these muscles caused by a damaged superior gluteal nerve can result in a weak abduction in the affected hip joint; this gait disturbance is known as Trendelenburg gait.
In a positive Trendelenburg's sign the pelvis sags toward the normal unsupported side. The opposite, when the pelvis is elevated on the swing side, is known as Duchenne limp. Bilateral loss of the small gluteal muscles results in a waddling gait. Inferior gluteal nerve This article incorporates text in the public domain from page 959 of the 20th edition of Gray's Anatomy 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. Superior_gluteal_nerve at the Duke University Health System's Orthopedics program
Lateral circumflex femoral artery
The lateral circumflex femoral artery is an artery in the upper thigh. The lateral femoral circumflex artery arises from the lateral side of the profunda femoris artery, passes horizontally between the divisions of the femoral nerve, behind the sartorius and rectus femoris, divides into ascending and descending branches; the lateral femoral circumflex artery may arise directly from the femoral artery. The artery courses anterior to the femoral neck and in between the branches of femoral nerve. A rare variant where the artery passes posterior to the femoral nerve has been reported, of great significance to the surgeon; the lateral circumflex femoral artery has three branches: The ascending branch of lateral circumflex femoral artery passes upward, beneath the tensor fasciae latae muscle, to the lateral aspect of the hip, anastomoses with the terminal branches of the superior gluteal and deep circumflex iliac artery. The descending branch of lateral circumflex femoral artery runs downward, behind the rectus femoris, upon the vastus lateralis, to which it gives offsets.
It is accompanied by the branch of the femoral nerve to the vastus lateralis muscle. The transverse branch of lateral circumflex femoral artery is a small artery in the thigh, it is the smallest branch of the lateral circumflex femoral artery and passes lateralward over the vastus intermedius, pierces the vastus lateralis, winds around the femur, just below the greater trochanter, anastomosing on the back of the thigh with the medial femoral circumflex artery, the inferior gluteal artery, the perforating arteries of the profunda femoris artery. Medial femoral circumflex artery This article incorporates text in the public domain from page 630 of the 20th edition of Gray's Anatomy Lateral_circumflex_femoral_artery at the Duke University Health System's Orthopedics program Anatomy figure: 12:04-01 at Human Anatomy Online, SUNY Downstate Medical Center - "Arteries of the lower extremity shown in association with major landmarks." Cross section image: pelvis/pelvis-e12-15—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
The gluteus maximus is the main extensor muscle of the hip. It is the largest and most superficial of the three gluteal muscles and makes up a large portion of the shape and appearance of each side of the hips, its thick fleshy mass, in a quadrilateral shape, forms the prominence of the buttocks. Its large size is one of the most characteristic features of the muscular system in humans, connected as it is with the power of maintaining the trunk in the erect posture. Other primates can not sustain standing erectly; the muscle is remarkably coarse in function and structure, being made up of muscle fascicles lying parallel with one another, collected together into larger bundles separated by fibrous septa. It arises from the posterior gluteal line of the inner upper ilium, a pelvic bone, the portion of the bone including the crest of the ilium above and behind it; the fibers are lateralward. Three bursae are found in relation with the deep surface of this muscle: One of these, of large size, separates it from the greater trochanter.
When the gluteus maximus takes its fixed point from the pelvis, it extends the acetabulofemoral joint and brings the bent thigh into a line with the body. Taking its fixed point from below, it acts upon the pelvis, supporting it and the trunk upon the head of the femur, its most powerful action is to cause the body to regain the erect position after stooping, by drawing the pelvis backward, being assisted in this action by the biceps femoris, semitendinosus and adductor magnus. The gluteus maximus is a tensor of the fascia lata, by its connection with the iliotibial band steadies the femur on the articular surfaces of the tibia during standing, when the extensor muscles are relaxed; the lower part of the muscle acts as an adductor and external rotator of the limb. The upper fibers act as abductors of the hip joints; the gluteus maximus is involved from running to weight-lifting. A number of exercises focus on the gluteus maximus as well as other muscles of the upper leg. Hip thrusts Glute bridge Quadruped hip extensions Kettlebell swings Squats and variations like split squats, pistol squats and wide-stance lunges Deadlift Reverse hyperextension Four-way hip extensions Glute-ham raise Functional assessment can be useful in assessing injuries to the gluteus maximus and surrounding muscles.
These tests include: 30 Second Chair to Stand testThis test measures a participant's ability to stand up from a seated position as many times as possible in a thirty-second period of time. Testing the number of times a person can stand up in a thirty-second period helps assess strength, flexibility and endurance, which can help determine how far along a person is in rehabilitation, or how much work is still to be done. Passive piriformis stretch; the piriformis test measures flexibility of the gluteus maximus. This requires a trained professional and is based on the angle of external and internal rotation in relation to normal range of motion without injury or impingement. In other primates, gluteus maximus consists of ischiofemoralis, a small muscle that corresponds to the human gluteus maximus and originates from the ilium and the sacroiliac ligament, gluteus maximus proprius, a large muscle that extends from the ischial tuberosity to a more distant insertion on the femur. In adapting to bipedal gait, reorganization of the attachment of the muscle as well as the moment arm was required.
Table of muscles of the human body Coccyx This article incorporates text in the public domain from page 474 of the 20th edition of Gray's Anatomy Anatomy photo:13:st-0403 at the SUNY Downstate Medical Center Cross section image: pelvis/pelvis-female-17—Plastination Laboratory at the Medical University of Vienna Cross section image: pelvis/pelvis-e12-15—Plastination Laboratory at the Medical University of Vienna Cross section image: pembody/body18b—Plastination Laboratory at the Medical University of Vienna Muscles/GluteusMaximus at exrx.net
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