Muscles of lower extremity Flashcards
Iliacus
Attachments: from iliac fossa to lesser trochanter of the femur
Actions: flexes thigh and stabilizes hip joint
Innervation: femoral n. & lumbar plexus branches
Blood supply: iliolumbar, deep circumflex iliac, femoral & obturator aa.
Psoas (L. muslce of the loin)
Attachments: from anterior lumbar transverse processes, vertebral bodies, & discs to the lesser trochanter of the femur
Actions: Flexes thight and stabilizes hip joint
Innervation: ventral rami L1-3
Blood supply: lumbar, iliolumbar, obturator, external iliac, & femoral aa.
Rectus femoris (L2, 3, 4) (L. straight)
Attachments: from anterior inferior iliac spine & groove superior to the acetabulum to the base of the patella
Actions: flexes thigh & extends leg
Innervation: Femoral n.
Blood supply: femoral, lateral circumflex femoral aa.
Sartorius (L. sartor, a tailor)
Attachments: from anterior superior iliac spine to the medial aspect of the proximal tibia
Actions: flexes, abducts & laterally rotates thigh, flexes leg
Innervation: femoral n.
Blood supply: femoral, lateral circumflex femoral, & descending genicular aa.
Tensor fasciae latae
Attachments: from anterior superior iliac spine & adjacent iliac crest to iliotibial tract
Actions: abducts, flexes, & medially rotates thigh, and assists in maintaining extended leg
Innervation: superior gluteal n.
Blood supply: lateral circumflex femoral (ascending), superior gluteal & superficial circumflex iliac aa.
Vastus intermedius (L2, 3, 4)
Attachments: from the anterior aspect of the proximal 2/3rds of the femoral shaft to the base of the patella
Actions: extends leg
Innervation: femoral n.
Blood supply: femoral and profunda femoral aa.
Vastus lateralis (L2, 3, 4)
Attachments: from lateral/posterior femur to the lateral border of the patella
Actions: extends leg
Innervation: femoral n.
Blood supply: lateral circumflex femoral (descending), femoral, & 1st perforating aa.
Vastus medialis (L2, 3, 4)
Attachments: from medial/posterior femur to medial border of the patella
Actions: extends leg
Innervation: femoral n.
Blood supply: femoral, profunda femoral & descending genicular aa.
Adductor brevis
Attachments: from inferior pubic ramus to proximal posterior femur
Actions: adducts thigh
Innervation: obturator n.
Blood supply: profunda femoral, medial circumflex femoral & obturator aa.
Adductor longus
Attachments: from pubic crest to midshaft posterior femur
Actions: adducts & flexes thigh
Innervation: obturator n.
Blood supply: profunda femoral, medial circumflex femoral, femoral & descending genicular aa.
Adductor magnus
Attachments: from ischial tuberosity to posterior femur & adductor tubercle
Actions: adducts (adductor part) & extends (hamstring part) thigh
Innervation: obturator n. (adductor region) & tibial division of the sciatic n. (hamstring region)
Blood supply: femoral, profunda femoral, obturator & descending genicular aa.
Gracilis (L. scanty)
Attachments: from inferior pubic ramus to the proximal, medial tibia
Actions: flexes & medially rotates leg, and adducts thigh
Innervation: obturator n.
Blood supply: profunda femoral & femoral aa.
Pectineus
Attachments: from superior pubic ramus to proximal posterior femoral shaft
Actions: adducts & flexes thigh
Innervation: femoral n. & accesory obturator n. when this nerve is present
Blood supply: medial circumflex femoral, femoral, & obturator aa.
Obturator externus
Attachments: from the external aspect of the rim of the obturator foramen to the trochanteric fossa
Actions: laterally rotates leg
Innervation: obturator n.
Blood supply: obturator & medial circumflex femoral aa.
Gemellus inferior (L. twin)
Attachments: from the ischial tuberosity to the obturator internus tendon
Actions: laterally rotates thigh
Innervation: sacral plexus (nerve to quadratus femoris)
Blood supply: medial circumflex femoral a.
Gemellus superior
Attachments: from the ischial spine to the obturator internus tendon
Actions: laterally rotates thigh
Innervation: sacral plexus (nerve to obturator internus)
Blood supply: inferior gluteal, internal pudendal aa.
Gluteus maximus
Attachments: from the aponeurosis of the erector spinae, sacrum, sacrotuberous lig. & gluteal surface of ilium to the gluteal tuberosity of the femur & the iliotibial tract
Actions: extends and laterally rotates thigh, & tenses fascia lata (iliotibial tract)
Innervation: inferior gluteal n.
Blood supply: inferior gluteal, superior gluteal, 1st perforating, medial circumflex femoral aa.
Gluteus medius
Attachments: from external iliac surface to the lateral aspect of the greater trochanter
Actions: abducts & medially rotates thigh; keeps the pelvis level when opposite leg is raised
Innervation: superior gluteal n.
Blood supply: superior gluteal & lateral circumflex femoral (ascending) aa.
Gluteus minimus
Attachments: from the external iliac surface to the anterolateral aspect of the greater trochanter
Actions: abducts & medially rotates thigh; keeps the pelvis level when opposite leg is raised
Innervation: superior gluteal n.
Blood supply: superior gluteal & lateral circumflex femoral (ascending) aa.
Obturator internus
Attachments: from the anterolateral wall of the pelvis, obturator foramen & obturator membrane to the medial surface of the greater trochanter
Actions: laterally rotates thigh
Innervation: sacral plexus (nerve to obturator internus)
Blood supply: obturator & internal pudendal aa.
Piriformis
Attachments: from the anterolateral sacrum to the upper border of the greater trochanter
Actions: abducts & laterally rotates thigh
Innervation: branches of the lumbosacral plexus
Blood supply: lateral sacral, superior gluteal & internal pudenal aa.
Biceps femoris
Attachments: from the ischial tuberosity (long head) & distal posterior/lateral femur (short head) to the fibular head
Actions: flexes leg (both heads) & extends thigh (long head only)
Innervation: tibial (long head) & common peroneal (short head) divisions of the sciatic n.
Blood supply: perforating branches of the profunda femoral & lateral superior genicular aa.
Semimembranosus
Attachments: from ischial tuberosity to posterior aspect of the medial tibial condyle
Actions: extends thigh & flexes leg
Innervation: tibial division of the sciatic n.
Blood supply: perforating branches of the profunda femoral a.
Semitendinosus
Attachments: from the ischial tuberosity to the proximal, medial tibia
Actions: extends thigh & flexes leg
Innervation: tibial division of the sciatic n.
Blood supply: perforating branches of the profunda femoral & medial circumflex femoral aa.
Extensor digitorum longus
Attachments: from the lateral tibial condyle, proximal fibula & interosseous membrane to the dorsal digital expansion of toes 2-5
Actions: dorsiflexes ankle & extends digits 2-5 (IP & MP)
Innervation: deep peroneal n.
Blood supply: anterior tibial a. & perforating branches of the peroneal a.
Extensor hallucis longus (L. hallex, great toe)
Attachments: from the mid-fibula & interosseous membrane to the distal phalangeal base of the 1st toe
Actions: dorsiflexes ankle & extends great toe (MP & IP)
Innervation: deep peroneal n.
Blood supply: anterior tibial a. & perforating branches of peroneal a.
Peroneus tertius
Attachments: from the distal fibula & interosseous membrane to the base of the 5th metatarsal
Actions: dorsiflexes ankle & initiates eversion of foot
Innervation: deep peroneal n.
Blood supply: anterior tibial a., perforating branch of peroneal a. & arcuate a.
Tibialis anterior
Attachments: from the lateral tibial condyle, proximal lateral tibia & interosseous membrane to the medial cuneiform & adjacent 1st metatarsal
Actions: dorsiflexes ankle & inverts foot
Innervation: deep peroneal n.
Blood supply: anterior tibial
Peroneus longus
Attachments: from the head & proximal fibula to the lateral aspects of the 1st metatarsal & adjacent medial cuneiform
Actions: plantar fexes ankle & everts foot
Innervation: superficial peroneal n.
Blood supply: anterior tibial & peroneal aa.
Peroneus brevis
Attachments: from the distal fibula to the lateral base of the 5th metatarsal
Actions: plantar flexes ankle & everts foot
Innervation: superficial peroneal n.
Blood supply: anterior tibial & peroneal aa.
Flexor digitorum longus
Attachments: from the posterior tibia distal to the soleal line to the plantar surfaces of the distal phalangeal bases
Actions: plantar flexes ankle & flexes digits 2-5 (MP & IP)
Innervation: tibial n.
Blood supply: posterior tibial a.
Flexor hallucis longus
Attachments: from the distal posterior fibular surface & interosseous membrane to the plantar aspect of the distal phalangeal base of the 1st toe
Actions: plantar flexes ankle & flexes great toe (MP & IP)
Innervation: tibial n.
Blood supply: posterior tibial & peroneal aa.
Gastrocnemius (S1, 2) (G. gaster, belly + kneme, leg)
Attachments: from the posterior aspect of the femoral condyles (lateral epicondyle & popliteal surface) to the calcaneal tuberosity
Actions: flexes leg & plantar flexes ankle
Innervation: tibial n.
Blood supply: medial & lateral sural aa.
Plantaris (L. planta, sole)
Attachments: from the lateral supracondylar line (popliteal surface) to the calcaneal tuberosity
Actions: flexes leg & plantar flexes ankle
Innervation: tibial n.
Blood supply: lateral sural, popliteal & lateral superior genicular aa.
Popliteus
Attachments: from the lateral femoral condyle to the soleal line of the tibia
Actions: unlocks knee during (initial) flexion
Innervation: tibial n.
Blood supply: medial & lateral inferior genicular aa.
Soleus (S1, 2)
Attachments: from the posterior proximal fibula & tibial soleal line to the calcaneal tuberosity
Actions: plantar flexes ankle
Innervation: tibial n.
Blood supply: posterior tibial & peroneal aa.
Tibialis posterior
Attachments: from the interosseous membrane, lateral tibia & medial fibula to the medial tarsals & metatarsals
Actions: plantar flexes ankle & inverts foot
Innervation: tibial n.
Blood supply: posterior tibial & peroneal aa.
Abductor digiti minimi
Attachments: from the calcaneal tuberosity to lateral side of proximal phalangeal base of 5th digit
Actions: abducts & flexes 5th digit
Innervation: lateral plantar n.
Blood supply: lateral plantar a.
Abductor hallucis
Attachments: from the medial calcaneal tuberosity to the medial side of the proximal phalangeal base of the great toe
Actions: flexes & abducts great toe
Innervation: medial plantar n.
Blood supply: medial plantar, medial malleollar & 1st plantar metatarsal aa.
Adductor hallucis
Attachments: from 2-4th metatarsal bases (oblique head) & distal ends of 3-5th metatarsals (transverse head) to lateral base of phalanx of great toe
Actions: adducts great toe
Innervation: lateral plantar n.
Blood supply: medial plantar, lateral plantar, plantar arch & 4th metatarsal aa.
Extensor digitorum brevis
Attachments: from anterolateral calcaneus to the lateral sides of tendons of extensor digitorum longus (2-4 or 2-5)
Actions: extension of digits 2-5 (MP & IP)
Innervation: deep peroneal n.
Blood supply: dorsalis pedis & arcuate aa.
Extensor hallucis brevis
Attachments: from anterolateral calcaneus to dorsal aspect of base of proximal phalanx of the hallux
Actions: extension of great toe (MP)
Innervation: deep peroneal n.
Blood supply: dorsalis pedis & arcuate aa.
Flexor digitorum accessorius (aka. quadratus plantae)
Attachments: from the medial surface of the calcaneus & lateral process of the calcaneal tuberosity to the long flexor tendons
Actions: assists flexor digitorum longus
Innervation: lateral plantar n.
Blood supply: medial plantar, lateral plantar & plantar arch
Flexor digitorum brevis
Attachments: from the medial process of the calcaneal tuberosity to sides of intermediate phalanges of digits 2-5
Actions: flexes toes (proximal IP)
Innervation: medial plantar n.
Blood supply: medial plantar, lateral plantar & plantar metatarsal aa.
Flexor digiti minimi
Attachments: from 5th metatarsal base to proximal phalangeal base
Actions: flexion of 5th digit (MP)
Innervation: lateral plantar n.
Blood supply: lateral plantar a.
Flexor hallucis brevis
Attachments: from cuboid & tendon of tibialis posterior to base of proximal phalanx of great toe
Actions: flexion of great toe (MP)
Innervation: medial plantar n.
Blood supply: medial plantar, 1st plantar metatarsal, lateral plantar & plantar arch
Interossei-dorsal
Attachments: from metatarsal shafts to proximal phalangeal bases & dorsal digital expansions of digits 2-4
Actions: abducts (MP), flexes (MP) & extends (IP) digits 2-4
Innervation: lateral plantar n.
Blood supply: arcuate, lateral tarsal, medial tarsal, dorsal metatarsal & dorsal digital aa.
Interossei-plantar
Attachments: from plantar surface of shaft of metatarsals to dorsal digital expansion of digits 3-5
Actions: adducts & flexes (MP), extends (IP) digits 3-5
Innervation: lateral plantar n.
Blood supply: lateral plantar, plantar arch & plantar metatarsal aa.
Lumbricals
Attachments: from tendons of flexor digitorum longus to medial sides of dorsal expansions of digits 2-5
Actions: flexes proximal phalanges (MP) & extends IP joints
Innervation: 1st- medial plantar n. &2-4-lateral plantar n.
Blood supply: lateral plantar, plantar arch & plantar metatarsal aa.
