Leg Muscles Flashcards
What are the flexors of the femur/thigh (at hip joint)?
illacus and psoas major, rectus femoris, sartorius, tensor fasciae latae, pectineus, adductor longus and brevis
What are the extensors of the femur/thigh?
gluteus maximus, semimembranosus, semitendinosus, biceps femoris (long head), adductor magnus (ischial part)
What are the adductors of the femur/thigh?
adductors longus, brevis, and magnus, gracilis
What are the abductors of the femur/thigh?
gluteus medius and minimus, tensor fasciae latae
What are the medial rotators of the femur?
gluteus minimus, gluteus medius (anterior fibers)
What are the lateral rotators of the femur?
gluteus maximus, sartorius, obturator internus, superior gemellus, obturator externus, quadratus femoris, inferior gemellus, piriformis
What is the action and innervation of the gluteus maximus?
extends and laterally rotates the hip; maintains knee extension via the iliotibial tract
inferior gluteal nerve (L5, S1, S2)
*think walking up stairs
What is the action and innervation of the gluteus medius?
abducts and medially rotates hip (inserts on posterolateral surface of greater trocanter of femur); tilts and stabilizes pelvis on one side while opposite side is off ground while walking
superior gluteal nerve (L4, L5, S1)
What is the action and innervation of the gluteus minimus?
abducts and medially rotates hip. Even more important for stabilizing pelvis
superior gluteal nerve (L4, L5, S1)
What type of gait can result by lesion to the superior gluteal nerve? What muscles are involved?
Trendelenburg gait pattern- the weakened abductor muscles allow the pelvis to tilt down on the opposite side
caused by weakness of the abductor muscles of the lower limb, gluteus medius and gluteus minimus
What is the action and innervation of the tensor fascia lata?
maintains knee extension (thus assisting the gluteus maximus) and abducts the hip
inserts into the iliotibial tract
superior gluteal nerve (L4, 5, S1)
What is the action and innervation of the piriformis?
laterally rotates and stabilizes the hip
inserts medial aspect of greater trocanter of femur
anterior primary rami of S1, S2
What is the action and innervation of the superior gemellus?
laterally rotates and stabilizes the hip
inserts medial aspect of greater trocanter of femur
nerve to obturator internus (L5, S1, S2)
What is the action and innervation of the obturator internus?
laterally rotates and stabilizes the hip
inserts medial aspect of greater trocanter of femur
nerve to obturator internus (L5, S1, S2)
What is the action and innervation of the inferior gemellus?
laterally rotates and stabilizes the hip
inserts medial aspect of greater trocanter of femur
nerve to quadratus femoris (L4, L5, S1)
What is the action and innervation of the quadratus femoris?
laterally rotates and stabilizes the hip
nerve to quadratus femoris (L4, L5, S1)
What muscles make up the hamstring?
biceps femoris, semitendinosis, semimembranosus
What innervates the muscles of the hamstring?
all except the short head of the biceps are innervated by the tibial nerve
short head of the biceps is innervated by the common fibular nerve
Where does the long head of the biceps femoris cross as compared to the short head?
long head crosses both the hip and the knee joint while the short head only crosses the knee joint
What is the action and innervation of the biceps femoris?
Flexes and laterally rotates the knee; Long head will extend the hip
Inserts at styloid process of fibular head, lateral collateral ligament and lateral tibial condyle
Long head: tibial portion of sciatic nerve
Short head: common peroneal/fibular portion of sciatic nerve
(both L5, S1)
What is the action and innervation of the semitendinosis?
flexes and medially rotates the knee. Extends hip.
inserts at upper medial shaft of tibia
tibial potion of sciatic nerve (L5, S1)
What is the action and innervation of the semimembranosus?
flexes and medially rotates the knee. extends hip
inserts at the medial condyle of the tibia and fascia over popliteus and oblique popliteal ligament
tibial portion of the sciatic nerve (L5, S1)
which of the hamstrings muscles is the most medial? most lateral?
semimembranosus is most medial and biceps femoris is most lateral
what two muscles of the body have tendons that enter a joint?
semimembranosus inserts into capsule around knee joint
biceps brachiii at elbow
What are the flexors of the tibia and fibula (at the knee)?
semimembranosus, semitendinosus, biceps femoris (long head and short head), gracilis, sartorius, politeus, gastrocnemius
What are the extensors of the tibia and fibula?
quadriceps femoris
what muscles make up the quadriceps femoris?
vastus medialis, vastus lateralis, vastus intermediua, rectus femoris
what is the only muscle of the quadriceps femoris to cross both the hip joint and the knee joint?
rectus femoris
What are the lateral rotators of the tibia and fibula?
gluteus maximus, biceps femoris, tensor fasciae latae
What are the medial rotators of the tibia and fibula?
popliteus (unlocks extended knee), semimembranosus, semitendinosus, gracilis, sartorius
what is the action and innervation of the psoas major?
flexes and laterally rotates the hip
inserts at lesser trocanter of femur
anterior primary rami of L1, L2
what is the action and innervation of the rectus femoris?
extends leg at knee, flexes thigh at hip
inserts as quadriceps tendon to patella via ligamentum patellae into tuberacle of tibia
posterior division of femoral nerve (L3, L4)
what is the action and innervation of the vastus lateralis?
extends knee
posterior division of femoral nerve (L3, L4)
what is the action and innervation of the vastus medialis?
extends knee, stabilizes patella
posterior division of femoral nerve (L3, L4)
what is the action and innervation of the vastus intermedius?
extends knee
posterior division of femoral nerve (L3, L4)
what is the action and innervation of the iliacus?
flexes and medially rotates hip
inserts at lesser trocanter of femur
femoral nerve in abdomen (L2, L3)
what is the action and innervation of the sartorius?
flexes, abducts, laterally rotates at the hip. flexes, medially rotates leg at knee
origin is below ASIS and insertion is at shaft of tibia on upper medial surface
anterior division of femoral nerve (L3, L4)
what is the action and innervation of the pectineus?
flexes, adducts, and medially rotates hip
anterior division of femoral nerve (L2, L3) (occasionally from obturator)
all the anterior thigh muscles are innervated by the __, except the __, which is innervated by the __
femoral nerve
psoas major
anterior rami of L1 and L2
what is the femoral triangle?
subfascial space in superior part of anterior thigh bounded superiorly by the inguinal ligament, medially by adductor longus, and laterally by sartorius
contain femoral nerve, femoral artery, femoral vein, deep inguinal lymph nodes and vessels (lateral to medial NAVL)
what is the adductor canal/adductor hiatus?
extends from the apex of the femoral triangle to the adductor hiatus (to posterior thigh) in tendon of adductor magnus muscles
passage for femoral artery and vein (to popliteal fossa to become popliteal vessels), saphenous nerve and nerve to vastus medialis
bounded anteriorly and laterally by the vastus medialis, posteriorly by the adductor longus and magnus, and medially by the sartorious
what is the longest muscle in the body?
sartorius
what is the action and innervation of the adductor longus?
adducts and medially rotates thip
anterior division of obturator nerve (L2, L3)
what is the action and innervation of the adductor brevis?
adducts hip… slightly flexes thigh
anterior division of obturator nerve (L2, L3)
what is the action and innervation of the adductor magnus?
TWO PORTIONS
adductor portion: adducts and medially rotates the hip; posterior division of obturator nerve (L2-L4); inserts at lower gluteal line and linea aspera
hamstring portion: extends hip; tibial portion of sciatic (L4-S3); inserts at adductor tuberacle
what is the action and innervation of the gracilis muscle?
adducts the hip; flexes knee and medially rotates flexed knee
anterior division of obturator nerve (L2, L3)
what is the action and innervation of the obturator externus?
laterally rotates hip, and steadies head of femur in the acetabulum
posterior division of the obturator nerve (L2-L4)
all muscles of the medial thigh are innervated by the __, except the __, which is innervated by the __
obturator nerve
hamstring portion of the adductor magnus
tibial part of the sciatic nerve
what are the plantar flexors of the foot?
gastrocnemius, soleus,. plantaris, tibialis posterior, flexor digitorum longus, flexor hallucis longus
what nerve is responsible for innervating the plantar flexor muscles of the foot?
tibial
what are the dorsiflexors of the foot?
tibialis anterior, extensor hallucis longus, extensor digitorum longus
what nerve is responsible for innervating the dorsi flexor muscles of the foot?
deep peroneal
what is the action and innervation of tibialis anterior?
dorsiflexes the foot at the ankle joint and inverts
deep peroneal/fibular
what is the action and innervation of the extensor digitorum longus?
extends lateral digits 2-4 and dorsiflexes the foot at the ankle joint
deep peroneal/fibular
what is the action and innervation of the extensor hallucis longus?
extends the great toe and dorsiflexes the foot
deep peroneal/fibular
what is the action and innervation of the fibularis/peroneus tertius muscle?
some dorsiflexion and everts the foot
deep peroneal/fibular
what is the action and innervation of the gastrocnemius muscle?
plantarflexes the foot and flexes the knee
tibial nerve
what is the action and innervation of the plantaris muscle?
plantarflexes the foot and flexes the knee
tibial nerve
*similar to palmaris longus is that it is sometimes absent in people
what is the action and innervation of the soleus muscle?
plantarflexes the foot
tibial nerve
what is the common tendon of the soleus and gastrocnemius muscles?
calcaneal tendon
what are the muscles of the anterior compartment of the leg? what are they innervated by? what is their blood supply?
tibialis anterior, extensor digitorum longus, extensor hallucis longus, fibularis tertius
deep fibular/peroneal nerve
anterior tibial artery
what are the muscles of the superior posterior compartment of the leg? what are they innervated by? what is their blood supply?
gastrocnemius, plantaris, soleus
tibial nerve
posterior tibial, fibular, popliteal arteries
what are the muscles of the deep posterior compartment of the leg? what are they innervated by? what is their blood supply?
popliteus, flexor hallucis longus, flexor digitorum longus, tibialis posterior
tibial nerve
posterior tibial, fibular, popliteal arteries
what is the action and innervation of the popliteus muscle?
unlocks the knee joint (laterally rotates the femur on a fixed tibia) for flexion
tibial nerve
what is the action and innervation of the flexor hallucis longus?
flexes the great toe
tibial nerve
what is the action and innervation of the flexor digitorum longus?
flexes digits 2-5
tibial nerve
what is the action and innervation of the tibialis posterior?
inverts and plantar flexes the foot, providing support to the medial arch of the foot during walking
tibial nerve
what are the muscles of the lateral compartment of the leg? what are they innervated by? what is their blood supply?
fibularis longus, fibularis brevis
superficial fibular nerve
anterior tibial and fibular arteries
what is the action and innervation of the fibularis/peroneus longus?
everts the foot, some plantarflexion
superficial fibular nerve
what is the action and innervation of the fibularis/peroneus brevis?
everts the foot, some plantarflexion
superficial peroneal nerve
what muscles invert the foot?
tibialis anterior, extensor hallucis longus, tibialis posterior
what muscles evert the foot?
peroneus longus, peroneus brevis, peroneus tertius
what muscles flex the great toe?
flexor hallucis longus and brevis
what muscles flex toes 2-5 at the distal interphalangeal joint?
flexor digitorum longus
what muscles flex toes 2-5 at the proximal interphalangeal joints?
flexor digitorum brevis
what muscles flex toes 2-5 at the metatarsophalangeal joints?
lumbrical I, lumbricals II, III, IV, interossei
what muscles flex toe 5 primarily?
flexor digiti minimi brevis
what muscles extend the great toe?
extensor hallucis longus and brevis
what muscles extend toes 2-4?
extensor digitorum longus and brevis
what muscles extend toes 2-5 at the interphalangeal joints?
lumbricals
what muscles abduct the great toe at the metatarsophalangeal joint?
abductor hallucis
what muscles abduct toes 2-4 at the metatarsophalangeal joints?
dorsal interossei
what muscles abduct toe 5 at the metatarsophalangeal joints?
abductor digiti minimi
what muscles adduct the great toe?
adductor hallucis
what muscles adduct toes 3-5?
plantar interossei
what is different about the dorsal aspect of the foot in comparison to the plantar aspect of the foot in regards to muscles?
dorsal aspect is a continuation of the anterior aspect of the leg
what are the muscles of the first layer of the plantar foot?
abductor digiti minimi, flexor digitorum brevis, abductor hallucis
(abductor, flexor, abductor)
what is the action and innervation of the abductor digiti minimi?
abducts and flexes toe 5
lateral plantar
what is the action and innervation of the flexor digitorum brevis?
flexes the lateral 4 digits
medial plantar nerve
what is the action and innervation of the abductor hallucis?
abducts and flexes the great toe
medial plantar nerve
what is innervated by the medial plantar nerve?
flexor digitorum brevis, flexor digitorum hallucis brevis, abductor hallucis, first lumbrical
(lateral plantar nerve will do the rest of the intrinsic muscles of the plantar foot)
what are the muscles of the second layer of the plantar foot?
lumbricals and quadratus plantae
what is the action and innervation of the lumbricals?
flex proximal phalanges, but extend the middle and distal phalanges because they insert on the dorsal digital expansions of toes 2-5
first lumbrical to toe 2 innervated by medial plantar, remaining lumbricals innervated by lateral plantar to toes 3-5
what is the action and innervation of the quadratus plantae?
assists flexor digitorum longus in flexing the lateral 4 toes
straightens tendon of the FD longus
lateral plantar nerve
what muscles are in the 3rd layer of the plantar foot?
flexor digiti minimi brevis, flexor hallucis brevis, adductor hallucis
(flexor, adductor, flexor)
what is the action and innervation of the flexor digiti minimi brevis?
flexes the proximal phalanx of toe 5
lateral plantar nerve
what is the action and innervation of the flexor hallucis brevis?
flexes the proximal phalanx of the great toe
medial plantar nerve
what is the action and innervation of the adductor hallucis?
adducts the great toe
lateral plantar nerve
what muscles are in the 4th layer of the plantar foot?
plantar interossei, dorsal interossei
what is the action and innervation of the plantar interossei?
adducts digits 3-5 and flexes the matatarsophalangeal joints of digits 3-5
lateral plantar
what is the action and innervation of the dorsal interossei?
abducts digits 2-4 and flexes the metatarsophalangeal joints
lateral plantar
