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9.7: Appendicular Muscles of the Pelvic Girdle and Lower Limbs

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    63432

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    By the end of this section, you will be able to:
    • Identify the major appendicular muscles of the pelvic girdle and lower limb
    • Identify the movement caused by these muscles

    The appendicular muscles of the lower body position and stabilize the pelvic girdle, which serves as a foundation for the lower limbs. Comparatively, there is much more movement at the pectoral girdle than at the pelvic girdle. There is very little movement of the pelvic girdle because of its connection with the sacrum at the base of the axial skeleton. The pelvic girdle is less range of motion because it was designed to stabilize and support the body.

    Muscles of the Thigh

    What would happen if the pelvic girdle, which attaches the lower limbs to the torso, were capable of the same range of motion as the pectoral girdle? For one thing, walking would expend more energy if the heads of the femurs were not secured in the acetabula of the pelvis. The body’s center of gravity is in the area of the pelvis. If the center of gravity were not to remain fixed, standing up would be difficult as well. Therefore, what the leg muscles lack in range of motion and versatility, they make up for in size and power, facilitating the body’s stabilization, posture, and movement.

    Gluteal and Pelvic Muscles That Move the Femur

    Most muscles that insert on the femur (the thigh bone) and move it, originate on the pelvic girdle (Table \(\PageIndex{1}\)).

    • The psoas major (the "p" is silent when pronouncing) and iliacus make up the iliopsoas group. These muscles originate on the posterior, interior of the pelvis and the vertebral column, pass over the pubis and insert into lesser trochanter of the femur. When they pass the inguinal ligament their fibers blend together so in the thigh the joined muscle is called the iliopsoas. Their anterior position relative to the hip joint makes them strong hip flexors (Figure \(\PageIndex{1}\)).
    • Some of the largest and most powerful muscles in the body are the gluteal muscles or gluteal group. From superficial to deep as well as largest to smallest these three muscles are the gluteus maximus, gluteus medius, and gluteus minimus. Gluteus maximus is the prime mover of hip extension as well as a lateral rotator. The gluteus medius and minimus both abduct and medially rotate the hip (Figure \(\PageIndex{1}\)). The gluteus maximus has two insertion points: one in the posterior femur and one on the superior, lateral tibia via that iliotibial (IT) band.
    Muscles - Iliopsoas Group.png
    Muscles - gluteal group posterior view.png
    Muscles - gluteal group lateral view.png
    Figure \(\PageIndex{1}\): Muscles - Iliopsoas and Gluteal Groups. The primary of action of these muscles is hip flexion (A. iliopsoas group) and hip extension, abduction, and rotation (B. gluteal group). (Image credits: "Iliopsoas and Gluteal Group Muscles" by Jennifer Lange are licensed under CC BY-NC-SA 4.0, based on images by University of British Columbia Clinical Anatomy)
    • Also in the gluteal compartment, the tensor fasciae latae (TFL) is a thick, squarish muscle in the superior aspect of the lateral thigh. It acts as a synergist of the gluteus medius in abducting the thigh. It also helps stabilize the lateral aspect of the knee by pulling on the iliotibial tract (band), making it taut (Figure \(\PageIndex{1}\)).
    • Deep to the gluteal muscles, the piriformis, superior gemellus, obturator externus, inferior gemellus, obturator internus, and quadratus femoris laterally rotate the femur at the hip (Figure \(\PageIndex{2}\)).
    Muscles - Deep Gluteal Group.png
    Figure \(\PageIndex{2}\): Muscles - Deep Gluteal Group. These small muscles stabilize the hip and help rotate it laterally. From superior to inferior they go in the the order of PG GO Q. (Image credits: "Deep Gluteal Group Muscles" by Jennifer Lange are licensed under CC BY-NC-SA 4.0, based on images by University of British Columbia Clinical Anatomy)

    Muscles of the Medial Compartment

    Six muscles are located in the medial compartment of the thigh (Figure \(\PageIndex{3}\)). Most of these muscles perform adduction at the hip joint, and each performs other actions as well. The adductor longus, adductor brevis, gracilis, and pectineus also flex the hip joint. Adductor magnus, depending on which fibers are activated, can flex, extend, and laterally rotate the thigh. Gracilis is the only one of this groups of muscles that does not insert into the femur, it inserts into the posterior, medial aspect of the superior tibia which also allows it to cause flexion at the knee joint. The only muscle in this compartment that does not adduct is the obturator externus, this muscle's action is to laterally rotate the hip.

    Muscles - Medial Thigh Anterior Group.png
    Muscles - Medial Thigh Posterior Group.png
    Muscles - Medial Thigh All.png
    Figure \(\PageIndex{3}\): Muscles - Medial Thigh Compartment. All but one of the muscles in this group cause thigh adduction because they cross the hip joint on the medial side. Image A shows the more anterior muscles, image B shows the more posterior muscles, and image C shows them all. (Image credits: "Medial Thigh Muscles" by Jennifer Lange are licensed under CC BY-NC-SA 4.0, based on images by University of British Columbia Clinical Anatomy)
    Table \(\PageIndex{1}\): Muscles that Move the Hip Joint
    Muscle Origin Insertion Movement Image(s)
    Iliopsoas group  
    Iliacus Iliac fossa; iliac crest; lateral sacrum Lesser trochanter of femur Flexes hip Muscles_Iliacus.png
    Psoas major Lumbar vertebrae (L1 - L5); thoracic vertebrae (T12) Lesser trochanter of femur Flexes hip Muscles_Psoas_Major.png
    Gluteal Group  
    Gluteus maximus Dorsal ilium; sacrum; coccyx Gluteal tuberosity of femur; iliotibial tract Extend and laterally rotates hip Muscles_Gluteus_Maximus.png
    Gluteus medius Lateral surface of ilium Greater trochanter of femur Abducts and medially rotates hip Muscles_Gluteus_Medius.png
    Gluteus minimus External surface of ilium Greater trochanter of femur Abducts and medially rotates hip Muscles_Gluteus_Minimus.png
    Tensor fascia lata Anterior aspect of iliac crest; anterior superior iliac spine Iliotibial tract Abducts and medially rotates hip Muscles_Tensor_Fasciae_Latae.png
    Deep Gluteal Muscles  
    Inferior gemellus Ischial tuberosity Greater trochanter of femur Laterally rotates hip; maintains posture by stabilizing hip joint Muscle - Inferior Gemellus.png
    Obturator externus Outer surfaces of obturator membrane, pubis, and ischium; margins of obturator foramen Trochanteric fossa of posterior femur Laterally rotates hip; maintains posture by stabilizing hip joint Muscle - Obturator Externus.png
    Obturator internus Inner surface of obturator membrane; greater sciatic notch; margins of obturator foramen Greater trochanter in front of piriformis Laterally rotates hip; maintains posture by stabilizing hip joint Muscle - Obturator Internus.png
    Piriformis Anterolateral surface of sacrum Greater trochanter of femur Laterally rotates hip; maintains posture by stabilizing hip joint Muscle - Piriformis.png
    Quadratus femoris Ischial tuberosity Trochanteric crest of femur Laterally rotates hip; maintains posture by stabilizing hip joint Muscle - Quadratus Femoris.png
    Superior gemellus Ischial spine Greater trochanter of femur Laterally rotates hip; maintains posture by stabilizing hip joint Muscle - Superior Gemellus.png
    Medial Muscles  
    Adductor brevis Body of pubis; inferior ramus of pubis Linea aspera above adductor longus Adducts and flexes hip Muscles_Adductor_Brevis.png
    Adductor longus Pubis near pubic symphysis Linea aspera Adducts and flexes hip Muscles_Adductor_Longus.png
    Adductor magnus Ischial rami; pubic rami; ischial tuberosity Linea aspera; adductor tubercle of femur

    Adducts hip

    Posterior fibers: extends and laterally rotates hip

    Anterior fibers: flex hip

    Muscles_Adductor_Magnus.png
    Gracilis Inferior ramus; body of pubis; ischial ramus Medial surface of tibia Adducts and flexes hip; flexes knee Muscles_Gracilis.png
    Pectineus Pectineal line of pubis Lesser trochanter to linea aspera of posterior aspect of femur Adducts and flexes hip Muscles_Pectineus.png

    Muscles of the Anterior Compartment

    The muscles of the anterior compartment of the thigh flex the thigh and extend the leg. This compartment contains the quadriceps femoris group, which actually comprises four muscles that extend and stabilize the knee (Figure \(\PageIndex{4}\)). The rectus femoris is on the anterior aspect of the thigh, the vastus lateralis is on the lateral aspect of the thigh, the vastus medialis is on the medial aspect of the thigh, and the vastus intermedius is between the vastus lateralis and vastus medialis and deep to the rectus femoris. The tendon common to all four is the quadriceps tendon (patellar tendon), which inserts into the patella and continues below it as the patellar ligament. The patellar ligament attaches to the tibial tuberosity.

    Muscles - Anterior Thigh Superficial.png
    Muscles - Anterior Thigh Deep.png
    Muscles - Anterior Thigh All.png
    Figure \(\PageIndex{4}\): Muscles - Anterior Thigh. The two superficial muscles (A) act on both the hip and knee joints. The deeper muscles (B) only act on the knee joint. When all muscles are shown, the vastus intermedius cannot be seen (C) because it is deep to the rectus femoris. (Image credits: "Anterior Thigh Muscles" by Jennifer Lange are licensed under CC BY-NC-SA 4.0, based on images by University of British Columbia Clinical Anatomy)

    In addition to the quadriceps femoris, the sartorius is a band-like muscle that extends from the anterior superior iliac spine to the medial side of the proximal tibia (Figure \(\PageIndex{4}\)). This versatile muscle flexes the leg at the knee and flexes, abducts, and laterally rotates the leg at the hip. This muscle allows us to sit cross-legged.

    Table \(\PageIndex{2}\): Thigh Muscles That Move the Femur, Tibia, and Fibula
    Muscle Origin Insertion Movement Image(s)
    Anterior Compartment of Thigh: Quadricepts Femoris Group  
    Rectus femoris Anterior inferior iliac spine; superior margin of acetabulum Patella; tibial tuberosity Moves lower leg out in front of body, as when kicking; assists in raising knee Muscles_Rectus_Femoris.png
    Sartorius Anterior superior iliac spine Medial aspect of proximal tibia Moves back of lower legs up and back toward the buttocks, as when kneeling; assists in moving thigh diagonally upward and outward as when mounting a bike Muscles_Sartorius.png
    Vastus intermedius Proximal femur shaft Patella; tibial tuberosity Moves lower leg out in front of body, as when kicking Muscle - Vastus Intermedius.png
    Vastus lateralis Greater trochanter; intertrochanteric line; linea apera Patella; tibial tuberosity Moves lower leg out in front of body, as when kicking Muscle - Vastus Lateralis.png
    Vastus medialis Linea aspera; intertrochanteric line Patella; tibial tuberosity Moves lower leg out in front of body, as when kicking Muscle - Vastus Medialis.png
    Posterior Compartment of Thigh: Hamstring Group  
    Biceps femoris Ischial tuberosity; linea aspera; distal femur Head of fibula; lateral condyle of tibia Moves back of lower legs up and back toward the buttocks, as when kneeling; moves thigh down and back; twists the thigh (and lower leg) outward Muscles_Biceps_Femoris.png
    Semimembranosus Ischial tuberosity Medial condyle of tibia; lateral condyle of femur Moves back of lower legs up and back toward the buttocks, as when kneeling; moves thigh down and back; twists the thigh (and lower leg) outward Muscles_Semimembranosus.png
    Semitendinosus Ischial tuberosity Upper tibial shaft Moves back of lower legs up and back toward the buttocks, as when kneeling; moves thigh down and back; twists the thigh (and lower leg) outward Muscles_Semitendinosus.png

    Muscles of the Posterior Compartment

    The posterior compartment of the thigh includes muscles that flex the leg and extend the thigh. The three long muscles on the back of the knee are the hamstring group, which flexes the knee and extends the hip. These are the biceps femoris (long head), semitendinosus, and semimembranosus. The biceps femoris also has a short head that is not considered part of the hamstrings because it only flexes the knee and does not extend the hip (Figure \(\PageIndex{5}\)). The tendons of these muscles form the popliteal fossa, the diamond-shaped space at the back of the knee.

    Muscles - Posterior Thigh Superficial.png
    Muscles - Posterior Thigh Deep.png
    Muscles - Posterior ThighAll.png
    Figure \(\PageIndex{5}\): Muscles - Posterior Thigh. The superficial (A) and deep (B) muscles of the hamstring group cross both the hip and the knee joints. The short head of the biceps femoris (B) is not considered a hamstring because it does not do both of these functions, but it is located in the posterior thigh. When all muscles are shown, the short head cannot be seen (C) because it is deep to the long head. (Image credits: "Posterior Thigh Muscles" by Jennifer Lange are licensed under CC BY-NC-SA 4.0, based on images by University of British Columbia Clinical Anatomy)

    Muscles That Move the Feet and Toes

    The muscles that move the ankle, foot, and toes and are located in the leg are called the crural muscles. Similar to the thigh muscles, the muscles of the leg are divided by fascia into compartments, although the leg has three: anterior, lateral, and posterior (Table \(\PageIndex{3}\)).

    Muscles of the Anterior Compartment

    The muscles in the anterior compartment of the leg: the tibialis anterior, a long and thick muscle on the lateral surface of the tibia, the extensor hallucis longus, deep under it, and the extensor digitorum longus, lateral to it, all contribute to raising the front of the foot when they contract. Some, but not all, people have a third muscle in this group called the fibularis tertius (tertius="third"), a small muscle that originates on the anterior surface of the fibula, is associated with the extensor digitorum longus and sometimes fused to it (Figure \(\PageIndex{6}\)).

    Muscles - Anterior Leg Superficial.png
    Muscles - Anterior Leg Deep.png
    Muscles - Anterior Leg All.png
    Figure \(\PageIndex{6}\): Muscles - Anterior Leg. The superficial (A) and deep (B) muscles of the anterior compartment of the leg cross both the ankle and joints in the foot. When all muscles are shown, only a small piece of the deep muscles can be seen (C), but you can easily identify the extensor hallicus longus because its tendon can be traced from the big toe. (Image credits: "Anterior Leg Muscles" by Jennifer Lange are licensed under CC BY-NC-SA 4.0, based on images by University of British Columbia Clinical Anatomy)

    Muscles of the Lateral Compartment

    The lateral compartment of the leg includes two muscles: the fibularis longus (aka peroneus longus) and the fibularis brevis (aka peroneus brevis) (Figure \(\PageIndex{7}\)). Fibularis longus is the more superficial of the two and it originates more proximally on the fibula than does the fibularis brevis. Both are strong everters of the foot and weak plantar flexors.

    Muscles - Lateral Leg.png
    Muscles - Lateral Leg Insertions.png
    Figure \(\PageIndex{7}\): Muscles - Lateral Leg. The two muscles in the lateral compartment of the leg run along the length of the fibula (A). Based on their insertion points (B), both muscles cause eversion of the foot. (Image credits: "Lateral Leg Muscles" by Jennifer Lange are licensed under CC BY-NC-SA 4.0, based on images by University of British Columbia Clinical Anatomy)

    Muscles of the Posterior Compartment

    The superficial muscles in the posterior compartment of the leg all insert onto the calcaneal tendon (Achilles tendon), a strong tendon that inserts into the posterior aspect of the calcaneaus, and all are plantar flexors of the ankle joint. The most superficial and visible muscle of the calf is the gastrocnemius. This muscle originates superior to the knee and inserts into the calcaneous, so it is responsible for both knee flexion and ankle plantar flexion. The gastrocnemius has two wide muscle bellies called the medial head and the lateral head. Deep to the gastrocnemius is the wide, flat soleus. This muscle is named because it resembles a flatfish. The two heads of the gastrocnemius together with the soleus are collectively called the triceps surae or, more commonly, the calf muscles. The plantaris is a small muscle with a long tendon that runs obliquely between the two large sural muscles; some people may have two of these muscles, whereas no plantaris is observed in about seven percent of other cadaver dissections.

    Muscles - Posterior Leg Superficial.png
    Muscles - Posterior Leg Deep.png
    Muscles - Posterior Leg Deep Tendons.png
    Figure \(\PageIndex{8}\): Posterior Leg Muscles. Superficial (A) and deep (B) views of the posterior compartment of the leg showing the muscles that plantar flex the ankle, invert the foot, and flex the toes as well as their tendinous insertions (C). (Image credits: "Posterior Leg Muscles" by Jennifer Lange are licensed under CC BY-NC-SA 4.0, based on images by University of British Columbia Clinical Anatomy)

    There are four deep muscles in the posterior compartment of the leg: the flexor digitorum longus, flexor hallucis longus, tibialis posterior and popliteus. Popliteus is a small muscle that runs diagonally across the popliteal region. Its main function is to "unlock" the knee joint through slight medial rotation and flexion. The three remaining muscles are located along the posterior surface of the tibia and the fibula, deep to the triceps surae (Figure \(\PageIndex{8}\)). All plantarflex the ankle joint. As their names suggest, flexor digitorum longus also flexes digits 2-5 and flexor hallucis longus also flexes the big toe. The secondary action of the tibialis posterior is inversion of the foot. The commonly used neumonic for the order of the tendons of these three muscles as they pass posterior to the medial malleolus is Tom, Dick, And Very Nervous Harry: T = Tibialis posterior, Dick = flexor Digitorum longus, A = artery, V = vein, N = nerve, H = flexor Hallicus longus.

    Table \(\PageIndex{3}\): Muscles That Move the Feet and Toes

    Prime Mover Origin Insertion Movement Image(s)
    Anterior Compartment of Leg
    Extensor digitorum longus Lateral condyle of tibia; proximal portion of fibula; interosseous membrane Middle and distal phalanges of toes 2 - 5 Extends toes 2-4; dorsiflexion of ankle Muscle - Extensor digitorum longus.png
    Extensor hallucis longus Anteromedial fibula shaft; interosseous membrane Distal phalanx hallux (big toe) Extends the big toe; dorsiflexion of ankle Muscle - Extensor halllicus longus.png
    Tibialis anterior Lateral condyle and upper tibial shaft; interosseous membrane Interior surface of medial cuneiform; first metatarsal bone Dorsiflexion of ankle; inversion of intertarsal Muscle - Tibialis Anterior.png
    Lateral Compartment of Leg
    Fibularis (peroneus) brevis Distal fibula shaft Proximal end of fifth metatarsal Eversion of intertarsal; plantarflexion of ankle Muscle - Fibularis brevis.png
    Fibularis (peroneus) longus Upper portion of lateral fibula First metatarsal; medial cuneiform Eversion of intertarsal, plantarflexion of ankle Muscle - fibularis longus.png
    Posterior Compartment of Leg: Superficial Muscles
    Gastrocnemius Medial and lateral condyles of femur Posterior calcaneus Plantarflexion of ankle; flexion of knee Muscle - Gastrocnemius.png
    Soleus Superior tibia; fibula; interosseous membrane Posterior calcaneus Plantarflexion of ankle Muscle - Soleus.png
    Posterior Compartment of Leg: Deep Muscles
    Flexor digitorum longus Posterior tibia Distal phalanges of toes 2 - 5 Flexion of digits 2-5; plantarflexion of ankle Muscle - Flexor digitorum longus.png
    Flexor hallucis longus Midshaft of fibula; interosseous membrane Distal phalanx of hallux (big toe) Flexes big toe; plantarflexion of ankle Muscle - Flexor hallicus longus.png
    Tibialis posterior Superior tibia; fibula; interosseous membrane Tarsals and metatarsals 2 - 4 Plantarflexion of ankle; inversion of intertarsal Muscle - Tibialis Posterior.png

    The foot also has intrinsic muscles, which originate and insert within it (similar to the intrinsic muscles of the hand). These muscles primarily provide support for the foot and its arch, and contribute to movements of the toes. The principal support for the longitudinal arch of the foot is a deep fascia called plantar aponeurosis, which runs from the calcaneus bone to the toes (inflammation of this tissue is the cause of “plantar fasciitis,” which can affect runners. 

    Muscles of the lower limb

    Explore the muscles of the lower limb in this 3D rending of a human leg model.

     


    Concept Review

    The pelvic girdle attaches the legs to the axial skeleton. The hip joint is where the pelvic girdle and the leg come together. The hip is joined to the pelvic girdle by many muscles. In the gluteal region, the psoas major and iliacus form the iliopsoas. The large and strong gluteus maximus, gluteus medius, and gluteus minimus extend and abduct the femur. Along with the gluteus maximus, the tensor fascia lata muscle forms the iliotibial tract. The lateral rotators of the femur at the hip are the piriformis, obturator internus, obturator externus, superior gemellus, inferior gemellus, and quadratus femoris. On the medial part of the thigh, the adductor longus, adductor brevis, and adductor magnus adduct the thigh and medially rotate it. The pectineus muscle adducts and flexes the femur at the hip.

    The thigh muscles that move the femur, tibia, and fibula are divided into medial, anterior, and posterior compartments. The medial compartment includes the adductors, pectineus, and the gracilis. The anterior compartment comprises the quadriceps femoris, quadriceps tendon, patellar ligament, and the sartorius. The quadriceps femoris is made of four muscles: the rectus femoris, the vastus lateralis, the vastus medius, and the vastus intermedius, which together extend the knee. The posterior compartment of the thigh includes the hamstrings: the biceps femoris, semitendinosus, and the semimembranosus, which all flex the knee.

    The muscles of the leg that move the foot and toes are divided into anterior, lateral, superficial- and deep-posterior compartments. The anterior compartment includes the tibialis anterior, the extensor hallucis longus, the extensor digitorum longus, and the fibularis (peroneus) tertius. The lateral compartment houses the fibularis (peroneus) longus and the fibularis (peroneus) brevis. The superficial posterior compartment has the gastrocnemius, soleus, and plantaris; and the deep posterior compartment has the popliteus, tibialis posterior, flexor digitorum longus, and flexor hallucis longus.


    Review Questions

    Q. The large muscle group that attaches the leg to the pelvic girdle and produces extension of the hip joint is the ________ group.

    A. gluteal

    B. obturator

    C. adductor

    D. abductor

    Answer

    Answer: A

    Q. Which muscle produces movement that allows you to cross your legs?

    A. the gluteus maximus

    B. the piriformis

    C. the gracilis

    D. the sartorius

    Answer

    Answer: D

    Q. What is the largest muscle in the lower leg?

    A. soleus

    B. gastrocnemius

    C. tibialis anterior

    D. tibialis posterior

    Answer

    Answer: B

    Q. The vastus intermedius muscle is deep to which of the following muscles?

    A. biceps femoris

    B. rectus femoris

    C. vastus medialis

    D. vastus lateralis

    Answer

    Answer: B

    Critical Thinking Questions

    Q. Which muscles form the hamstrings? How do they function together?

    Answer

    A. The biceps femoris, semimembranosus, and semitendinosus form the hamstrings. The hamstrings flex the leg at the knee joint.

    Q. Which muscles form the quadriceps? How do they function together?

    Answer

    A. The rectus femoris, vastus medialis, vastus lateralis, and vastus intermedius form the quadriceps. The quadriceps muscles extend the leg at the knee joint.

    Glossary

    adductor brevis
    muscle that adducts and medially rotates the thigh
    adductor longus
    muscle that adducts, medially rotates, and flexes the thigh
    adductor magnus
    muscle with an anterior fascicle that adducts, medially rotates and flexes the thigh, and a posterior fascicle that assists in thigh extension
    anterior compartment of the leg
    region that includes muscles that dorsiflex the foot
    anterior compartment of the thigh
    region that includes muscles that flex the thigh and extend the leg
    biceps femoris
    hamstring muscle
    calcaneal tendon
    (also, Achilles tendon) strong tendon that inserts into the calcaneal bone of the ankle
    extensor digitorum brevis
    muscle that extends the toes
    extensor digitorum longus
    muscle that is lateral to the tibialis anterior
    extensor hallucis longus
    muscle that is partly deep to the tibialis anterior and extensor digitorum longus
    femoral triangle
    region formed at the junction between the hip and the leg and includes the pectineus, femoral nerve, femoral artery, femoral vein, and deep inguinal lymph nodes
    fibularis brevis
    (also, peroneus brevis) muscle that plantar flexes the foot at the ankle and everts it at the intertarsal joints
    fibularis longus
    (also, peroneus longus) muscle that plantar flexes the foot at the ankle and everts it at the intertarsal joints
    fibularis tertius
    small muscle that is associated with the extensor digitorum longus
    flexor digitorum longus
    muscle that flexes the four small toes
    flexor hallucis longus
    muscle that flexes the big toe
    gastrocnemius
    most superficial muscle of the calf
    gluteal group
    muscle group that extends, flexes, rotates, adducts, and abducts the femur
    gluteus maximus
    largest of the gluteus muscles that extends the femur
    gluteus medius
    muscle deep to the gluteus maximus that abducts the femur at the hip
    gluteus minimus
    smallest of the gluteal muscles and deep to the gluteus medius
    gracilis
    muscle that adducts the thigh and flexes the leg at the knee
    hamstring group
    three long muscles on the back of the leg
    iliacus
    muscle that, along with the psoas major, makes up the iliopsoas
    iliopsoas group
    muscle group consisting of iliacus and psoas major muscles, that flexes the thigh at the hip, rotates it laterally, and flexes the trunk of the body onto the hip
    iliotibial tract
    muscle that inserts onto the tibia; made up of the gluteus maximus and connective tissues of the tensor fasciae latae
    inferior gemellus
    muscle deep to the gluteus maximus on the lateral surface of the thigh that laterally rotates the femur at the hip
    lateral compartment of the leg
    region that includes the fibularis (peroneus) longus and the fibularis (peroneus) brevis and their associated blood vessels and nerves
    medial compartment of the thigh
    a region that includes the adductor longus, adductor brevis, adductor magnus, pectineus, gracilis, and their associated blood vessels and nerves
    obturator externus
    muscle deep to the gluteus maximus on the lateral surface of the thigh that laterally rotates the femur at the hip
    obturator internus
    muscle deep to the gluteus maximus on the lateral surface of the thigh that laterally rotates the femur at the hip
    patellar ligament
    extension of the quadriceps tendon below the patella
    pectineus
    muscle that abducts and flexes the femur at the hip
    pelvic girdle
    hips, a foundation for the lower limb
    piriformis
    muscle deep to the gluteus maximus on the lateral surface of the thigh that laterally rotates the femur at the hip
    plantar aponeurosis
    muscle that supports the longitudinal arch of the foot
    plantaris
    muscle that runs obliquely between the gastrocnemius and the soleus
    popliteal fossa
    diamond-shaped space at the back of the knee
    popliteus
    muscle that flexes the leg at the knee and creates the floor of the popliteal fossa
    posterior compartment of the leg
    region that includes the superficial gastrocnemius, soleus, and plantaris, and the deep popliteus, flexor digitorum longus, flexor hallucis longus, and tibialis posterior
    posterior compartment of the thigh
    region that includes muscles that flex the leg and extend the thigh
    psoas major
    muscle that, along with the iliacus, makes up the iliopsoas
    quadratus femoris
    muscle deep to the gluteus maximus on the lateral surface of the thigh that laterally rotates the femur at the hip
    quadriceps femoris group
    four muscles, that extend and stabilize the knee
    quadriceps tendon
    (also, patellar tendon) tendon common to all four quadriceps muscles, inserts into the patella
    rectus femoris
    quadriceps muscle on the anterior aspect of the thigh
    sartorius
    band-like muscle that flexes, abducts, and laterally rotates the leg at the hip
    semimembranosus
    hamstring muscle
    semitendinosus
    hamstring muscle
    soleus
    wide, flat muscle deep to the gastrocnemius
    superior gemellus
    muscle deep to the gluteus maximus on the lateral surface of the thigh that laterally rotates the femur at the hip
    tensor fascia lata
    muscle that flexes and abducts the thigh
    tibialis anterior
    muscle located on the lateral surface of the tibia
    tibialis posterior
    muscle that plantar flexes and inverts the foot
    vastus intermedius
    quadricep muscle that is between the vastus lateralis and vastus medialis and is deep to the rectus femoris
    vastus lateralis
    quadricep muscle on the lateral aspect of the thigh
    vastus medialis
    quadricep muscle on the medial aspect of the thigh

    Contributors and Attributions


    This page titled 9.7: Appendicular Muscles of the Pelvic Girdle and Lower Limbs is shared under a CC BY-NC-SA 4.0 license and was authored, remixed, and/or curated by Jennifer Lange et al..