Lower Limb Muscles | Anatomy2Medicine
Lower Limb Muscles

Lower Limb Muscles

MUSCLES OF THE GLUTEAL REGION

    • Sacrotuberous Ligament

 

  • Extends from the ischial tuberosity to the posterior iliac spines, lower sacrum, and coccyx.
  • Converts, with the sacrospinous ligament, the lesser sciatic notch into the lesser sciatic foramen.

 

    • Sacrospinous Ligament
      • Extends from the ischial spine to the lower sacrum and coccyx.
      • Converts the greater sciatic notch into the greater sciatic foramen.
    • Sciatic Foramina

 

  • Greater Sciatic Foramen

 

        • Provides a pathway for the

 

  • piriformis muscle

 

          • superior and inferior gluteal vessels and nerves
          • internal pudendal vessels

 

  • pudendal nerve

 

          • sciatic nerve

 

  • posterior femoral cutaneous nerve

 

          • nerves to the obturator internus and quadratus femoris muscles.

 

  • Lesser Sciatic Foramen

 

        • Provides a pathway for the
          • tendon of the obturator internus
          • the nerve to the obturator internus
          • internal pudendal vessels and pudendal nerve.
      • Structures that Pass through both the Greater and the Lesser Sciatic Foramina

 

  • pudendal nerve
  • internal pudendal vessels,
  • nerve to the obturator internus.

 

  • Iliotibial Tract
    • Is a thick lateral portion of the fascia lata.
    • Provides insertion for the gluteus maximus and tensor fasciae latae muscles.
    • Helps form the fibrous capsule of the knee joint
    • important in maintaining posture and locomotion.
  • FasciaLata
    • Is a membranous, deep fascia covering muscles of the thigh
    • It forms the lateral and medial intermuscular septa by its inward extension to the femur.
    • Is attached to the pubic symphysis, pubic crest, pubic rami, ischial tuberosity, inguinal and sacrotuberous ligaments, and the sacrum and coccyx.
    • FasciaLata

      FasciaLata

      lateral and medial intermuscular septa

      lateral and medial intermuscular septa

      Muscles of the anterior and medial thigh

        • Femoral Triangle
          • Is bounded by the
            • inguinal ligament superiorly
            • sartorius muscle laterally
            • adductor longus muscle medially.
          • floor is formed by

    • iliopsoas
    • pectineus
    • adductor longus muscles
          • roof is formed by the

    • fascia lata
    • cribriform fascia.
          • Contains the femoral nerve, artery, vein, and lymphatics (in the canal).
            • NAVY – structures from lateral to medial (nerve, artery, vein, yahoo!!!).

    • The pulsation of the femoral artery may be felt just inferior to the midpoint of the inguinal ligament.
        • Femoral Ring
          • Is the abdominal opening of the femoral canal.
          • Is bounded by the
            • inguinal ligament anteriorly
            • femoral vein laterally
            • lacunar ligament medially
            • pectineal ligament posteriorly.
        • Femoral Canal
          • Lies medial to the femoral vein in the femoral sheath.

    • Contains fat, areolar connective tissue, and lymph nodes and vessels.
          • Transmits lymphatics from the lower limb and perineum to the peritoneal cavity.
          • Is a potential weak area and a site of femoral herniation

    • Femoral hernia occurs most frequently in women because of the greater width of the superior pubic ramus of the female pelvis.
  • perior pubic ramus of the female pelvis.

    perior pubic ramus of the female pelvis.

    Presentation2

    Presentation2

      • Femoral Sheath
        • Is formed by a prolongation of the transversalis and iliac fasciae in the thigh.
        • Contains the

  • femoral artery and vein
  • femoral branch of the genitofemoral nerve
          • femoral canal.
        • The femoral nerve lies outside the femoral sheath, lateral to the femoral artery.
        • Reaches the level of the proximal end of the saphenous opening with its distal end.
      • Adductor Canal

  • Begins at the apex of the femoral triangle and ends at the adductor hiatus
  • Lies between the adductor magnus and longus muscles and the vastus medialis muscle
        • covered by the sartorius muscle and fascia.
        • Contains the

  • femoral vessels
  • saphenous nerve
  • nerve to the vastus medialis
  • descending genicular artery.
      • Adductor Hiatus (Hiatus Tendineus)

  • Is the aperture in the tendon of insertion of the adductor magnus.
  • Allows the passage of the femoral vessels into the popliteal fossa.
    • Saphenous Opening (Saphenous Hiatus) or Fossa Ovalis
      • Is an oval gap in the fascia lata below the inguinal ligament
      • covered by the cribriform fascia, which is a part of the superficial fascia of the thigh.
      • Provides a pathway for the greater saphenous vein.

    Anterior and lateral muscles of the leg

      • Popliteal Fossa
        • Is bounded
          • superomedially by the semitendinosus and semimembranosus muscles, superolaterally by the biceps muscle
          • inferolaterally by the lateral head of the gastrocnemius and plantaris muscles
          • inferomedially by the medial head of the gastrocnemius muscle.
        • Has a floor that is composed of the

  • Femur
  • oblique popliteal ligament
  • popliteus muscle.
        • Contains

  • popliteal vessels
  • common peroneal and tibial nerves
  • small saphenous vein.
    • Pes Anserinus
      • Is the combined tendinous expansions of the sartorius, gracilis, and semitendinosus muscles
      • Occur at the medial border of the tuberosity of the tibia
      • It may be used for surgical repair of the anterior cruciate ligament of the knee joint.
      • Muscles of the foot

        Muscles of the foot

        Muscles of the foot

          • Superior Extensor Retinaculum
            • Is a broad band of deep fascia
            • extends between the tibia and fibula, above the ankle.
          • Inferior Extensor Retinaculum
            • Is a Y-shaped band of deep fascia
            • forms a loop for the tendons of the extensor digitorum longus and the peroneus tertius
            • divides into an
              • upper band, which attaches to the medial malleolus

      • lower band, which attaches to the deep fascia of the foot and the plantar aponeurosis.
          • Flexor Retinaculum
            • Is a deep fascial band
            • passes between the medial malleolus and the medial surface of the calcaneus

      • forms the tarsal tunnel with tarsal bones for the tibial nerve, posterior tibial vessels, and flexor tendons.
            • Holds three tendons and blood vessels and a nerve in place deep to it (from anterior to posterior) Tom, Dick ANd Harry

      • tibialis posterior
      • flexor digitorum longus
      • posterior tibial artery and vein
      • tibial nerve,
      • flexor hallucis longus
            • Provides a pathway for the tibial nerve and posterior tibial artery beneath it.
          • Tendo Calcaneus (Achilles Tendon)
            • Is the tendon of insertion of the triceps surae (gastrocnemius and soleus) into the tuberosity of the calcaneus.
          • Plantar Aponeurosis
            • Is a thick fascia investing the plantar muscles.
            • Radiates from the calcaneal tuberosity (tuber calcanei) toward the toes
            • Provides attachment to the short flexor muscles of the toes.
          • Arches of the Foot
            • Medial Longitudinal Arch

      • Is formed and maintained by the interlocking of the talus, calcaneus, navicular, cunei- form, and three medial metatarsal bones.
              • Has, as its keystone, the head of the talus, which is located at the summit between the sustentaculum tali and the navicular bone.

      • Is supported by the spring ligament and the tendon of the flexor hallucis longus.
            • Lateral Longitudinal Arch
              • Is formed by the calcaneus, the cuboid bone, and the lateral two metatarsal bones. The keystone is the cuboid bone.

      • Is supported by the peroneus longus tendon and the long and short plantar liga- ments.
              • Supports the body in the erect position
              • acts as a spring in locomotion
            • Transverse Arch
              • Proximal (metatarsal) arch

      • Is formed by the navicular bone, the three cuneiform bones, the cuboid bone, and the bases of the five metatarsal bones of the foot.
                • Is supported by the tendon of the peroneus longus.
              • Distal arch
                • Is formed by the heads of five metatarsal bones.

      • Is maintained by the transverse head of the adductor hallucis.
          • Ligaments

      • Long Plantar (Plantar Calcaneocuboid) Ligament
              • forms a canal for the tendon of the peroneus longus.
              • Supports the lateral side of the longitudinal arch of the foot.

      • Short Plantar (Plantar Calcaneocuboid) Ligament
            • Spring (Plantar Calcaneonavicular) Ligament
              • Passes from the sustentaculum tali of the calcaneus to the navicular bone.

      • Supports the head of the talus and the medial longitudinal arch.
            • Is called the spring ligament because it contains considerable numbers of elastic fibers to give elasticity to the arch and spring to the foot.
            • Is supported by the tendon of the tibialis posterior.

      • Summary of muscle actions of the lower limb
      • Movements at the Hip Joint (Ball-and-Socket Joint)
              • Flexion—iliopsoas, tensor fasciae latae, rectus femoris, adductors, sartorius, pectineus, gracilis
              • Extension—hamstrings, gluteus maximus, adductor magnus
              • Adduction—adductor magnus, adductor longus, adductor brevis, pectineus, gracilis Abduction—gluteus medius, gluteus minimus
              • Medial rotation—tensor fasciae latae, gluteus medius, gluteus minimus
              • Lateral rotation—obturator internus, obturator externus, gemelli, piriformis, quadratus femoris, gluteus maximus

      • Movements at the Knee Joint (Hinge Joint)
              • Flexion—hamstrings, gracilis, sartorius, gastrocnemius, popliteus Extension—quadriceps femoris
              • Medial rotation—semitendinosus, semimembranosus, popliteus Lateral rotation—biceps femoris
              • Movements at the Ankle Joint (Hinge Joint)
              • Dorsiflexion—anterior tibialis, extensor digitorum longus, extensor hallucis longus, peroneus tertius
              • Plantar flexion—triceps surae, plantaris, posterior tibialis, peroneus longus and brevis, flexor digitorum longus, flexor hallucis longus (when the knee is fully flexed)

      • Movements at the Intertarsal Joint (Talocalcaneal, Transverse Tarsal Joint)
              • Inversion—tibialis posterior, tibialis anterior, triceps surae, extensor hallucis longus
              • Eversion—peroneus longus, brevis, and tertius, extensor digitorum longus

      • Movements at the Metatarsophalangeal Joint (Ellipsoid Joint)
            • Flexion—lumbricals, interossei, flexor hallucis brevis, flexor digiti minimi brevis
            • Extension—extensor digitorum longus and brevis, extensor hallucis longus
          • Movements at the Interphalangeal Joint (Hinge Joint)
            • Flexion—flexor digitorum longus and brevis, flexor hallucis longus
            • Extension—extensor digitorum longus and brevis, extensor hallucis longus

      • Summary of muscle innervations of the lower limb
      • Muscles of the Gluteal Region
              • Gluteus maximus (inferior gluteal nerve)
              • Gluteus medius (superior gluteal nerve)
              • Gluteus minimus (superior gluteal nerve)
              • Tensor fasciae latae (superior gluteal nerve)
              • Piriformis (nerve to piriformis)
              • Obturator internus (nerve to obturator internus)
              • Superior gemellus (nerve to obturator internus)
              • Inferior gemellus (nerve to quadratus femoris)
              • Quadratus femoris (nerve to quadratus femoris)

      • Muscles of the thigh
      • Muscles of the Anterior Compartment: Femoral Nerve
                • Sartorius,
                • quadriceps femoris
                • rectus femoris, vastus medialis, vastus intermedius, vastus lateralis

      • Muscles of the Medial Compartment: Obturator Nerve
                • Adductor longus
                • adductor brevis,
                • adductor magnus (obturator and tibial nerves) (MCQ)
                • gracilis, obturator externus
                • pectineus (femoral and obturator nerves) (MCQ)

      • Muscles of the Posterior Compartment: Tibial Part of Sciatic Nerve
                • Semitendinosus; semimembranosus; biceps femoris, long head
                • biceps femoris, short head (common peroneal part of sciatic nerve) (MCQ)
                • adductor magnus (tibial part of sciatic and obturator nerve) (MCQ)

      • Muscles of the leg
      • Muscles of the Anterior Compartment: Deep Peroneal Nerve
                • Tibialis anterior, extensor digitorum longus
                • extensor hallucis longus, peroneus tertius

      • Muscles of the Lateral Compartment: Superficial Peroneal Nerve
                • Peroneus longus, peroneus brevis

      • Muscles of the Posterior Compartment: Tibial Nerve
                • Superficial layer—gastrocnemius, soleus, plantaris
                • Deep layer—popliteus, tibialis posterior, flexor digitorum longus, flexor hallucis longus

      • Muscles of the foot
      • Muscles of the Anterior Compartment (Dorsum): Deep Peroneal Nerve
                • Extensor digitorum brevis, extensor hallucis brevis

      • Muscles of the Plantar Compartment (Sole): Medial and Lateral Plantar Nerves
      • Medial plantar nerve
                  • Flexor digitorum brevis
                  • abductor halluces
                  • flexor hallucis brevis
                  • first lumbrical

      • lateral plantar nerve
                  • Quadratus plantae
                  • abductor digiti minimi
                  • lateral three lumbricals
                  • adductor hallucis, flexor digiti minimi brevis
                  • plantar interossei, dorsal interossei

      • Surgical Anatomy
      • Gluteal gait (gluteus medius limp)
            • waddling gait
            • characterized by the pelvis falling (or drooping) toward the unaffected side when the opposite leg is raised at each step
            • It results from paralysis of the gluteus medius muscle, which normally functions to stabilize the pelvis when the opposite foot is off the ground.

      • gluteal region —  intramuscular injection of medications
            • Injection should always be made in the superior lateral quadrant of the gluteal region
            • to avoid injury to the underlying sciatic nerve and other neurovascular structures in the medial and inferior quadrants.
                  • Piriformis syndrome
            • piriformis muscle irritates and places pressure on the sciatic nerve causes
              • pain in the buttocks
              • referring pain along the course of the sciatic nerve (“sciatica,”)
                  • Positive Trendelenburg’s sign
            • seen in a

      • fracture of the femoral neck
      • dislocated hip joint (head of femur)
            • weakness and paralysis of the gluteus medius and minimus muscle
            • causes inability to abduct the hip
            • If the right gluteus medius and minimus muscles are paralyzed, the unsupported left side (sound side) of the pelvis falls (sags) instead of rising; normally the pelvis rises.
                  • Hamstring injury or strains (pulled or torn hamstrings)
            • common in persons who are involved in running, jumping, and quick-start sports.

      • origin of the hamstrings from the ischial tuberosity may be avulsed
            • result in rupture of blood vessels.
                  • Avulsion of the ischial tuberosity
            • result from forcible flexion of the hip with the knee extended
            • tearing of hamstring fibers is very painful.

      • Femoral hernia
            • more common in women than in men
            • passes through the femoral ring and canal
            • lies lateral and inferior to the pubic tubercle and deep and inferior to the inguinal ligament;
            • its sac is formed by the parietal peritoneum.

      • Strangulation of a femoral hernia may occur because of the sharp, stiff boundaries of the femoral ring
                  • Groin injury or pulled groin
            • strain, stretching, or tearing of the origin of the flexor and adductor of the thigh

      • often occurs in sports that require quick starts such as a 100-meter dash and football.
                  • Gracilis
            • a relatively weak member of the adductor group of muscles
            • surgeons often transplant this muscle or part of it, with nerve and blood vessels, to replace a damaged muscle in the hand.
                  • Anterior tibial compartment syndrome
            • characterized by ischemic necrosis of the muscles of the anterior compartment of the leg.
            • occurs presumably as a result of compression of arteries (anterior tibial artery and its branches) by swollen muscles following excessive exertion
            • It is accompanied by extreme tenderness and pain on the anterolateral aspect of the leg.
                  • Knee-jerk (patellar) reflex
            • tests the L2–L4 spinal (femoral) nerves

      • Ankle-jerk (Achilles)
            • its reflex center in the L5–S1 or S1–S2 segments of the spinal cord.
                  • Tarsal tunnel syndrome
            • compression of the tibial nerve or its medial and lateral plantar branches in the tarsal tunnel
            • pain, numbness, and tingling sensations on the ankle, heel, and sole of the foot.
            • It may be caused by repetitive stress with activities, flat feet, or excess weight.
                  • Avulsion or rupture of the Achilles tendon
            • disables the triceps surae (gastrocnemius and soleus) muscles;

      • patient is unable to plantar flex the foot
      • Forced eversion of the foot avulses the medial malleolus or ruptures the deltoid ligament,
                  • Forced inversion avulses the lateral malleolus or tears the lateral collateral (anterior and posterior talofibular and calcaneofibular) ligament.
                  • Ankle sprain (inversion injury) results from
            • caused by forced inversion of the foot

      • caused by
      • rupture of calcaneofibular and talofibular ligaments
              • fracture of the lateral malleolus
                  • Flat foot (pes planus or talipes planus)
            • condition of disappearance or collapse of the medial longitudinal arch
            • occur with eversion and abduction of the forefoot
            • causes greater wear on the inner border of the soles and heels of shoes than on the outer border.

      • It causes pain as a result of
              • stretching of the plantar muscles
              • straining of the spring ligament and the long and short plantar ligaments.
                  • Pes cavus
            • exaggerated height of themedial longitudinal arch of the foot.

      • Clubfoot (talipes equinovarus)
      • foot is plantarflexed, inverted, and adducted
          • causes deformity in which the
          • foot is plantarflexed (equinus) or  dorsiflexed (calcaneus)
          • heel is turned laterally (valgus) or medially (varus),
          • heel is elevated and turned laterally (equinovalgus) or medially (equinovarus)
          • anterior part of the foot (forefoot) is elevated and the heel is turned laterally (calcaneovalgus) or medially (calcaneovarus).