Lower Extremity Flashcards
Iliacus
O: Posterior abdominal wall (iliac fossa, iliac crest, ala of the sacrum)
I: Tendons of psoas major, lesser trochanter and femur
A: With the origin fixed: flexion and weak ER of hip
With the insertion fixed: Flex the trunk toward the thigh, Tilt the pelvis anteriorly
N: Femoral nerve (L2, L3)
Psoas major
O: Posterior abdominal wall (lumbar transverse process, intervertebral discs, and adjacent bodies
from T12 to L5 and tendinous arches between these points)
I: Lesser trochanter of femur
A: With origin fixed: flexion (coaxial joint) and weak ER of hip
With insertion fixed: Flex the trunk toward the thigh, Tilt pelvic anteriorly
N: Anterior rami (L1, L2, L3)
Sartorius
O: Anterior superior iliac spine
I: Medial surface of the tibia just inferomedial to tibial tuberosity at pes anserinus tendon
A: Flexion of hip and knee joint (also weak ER and ABD of the hip and IR flexed knee)
N: Femoral nerve (L2, L3)
Quadriceps Femoris: Rectus Femoris
O: Anterior inferior iliac spine
I: Tibial tuberosity (via the patella and patella ligament)
A: Flexion of hip joint and extension of knee joint
N: Femoral nerve (L2, L3, L4)
Quadriceps Femoris: Vastus intermedius
O: Proximal two-thirds of the anterior and lateral surface of the femur
I: Tibial tuberosity (via patella and patella ligament)
A: Extension of knee joint
N: Femoral nerve (L2, L3, L4)
Quadriceps Femoris: Vastus medialis
O: Medial part of intertrochantereic line and medial lip of the linea aspera,
I: Tibial tuberosity (via patella and patella ligament)
A: Extension of knee joint
N: Femoral nerve (L2, L3, L4)
Quadriceps Femoris: Vastus lateralis
O: Lateral lip of linea aspera, gluteal tuberosity and greater trochanter
I: Tibial tuberosity (via patella and patella ligament)
A: Extension of knee joint
N: Femoral nerve (L2, L3, L4)
Pectineus
O: Superior ramus of pubis
I: Pectineal line of femur
A: Adduct, IR, and flex hip joint
N: Femoral nerve (L2, L3) and possibly Obturator Nerve (L2-L4)
Adductor longus
O: Body of the pubis inferior to the pubic crest
I: Distal aspect of the medial lip of linea aspera
A: Adduct and IR hip joint
N: Obturator nerve (anterior division) (L2, L3, L4)
Adductor brevis
O: External surface of body of pubis and inferior pubic ramus
I: Pectineal line and proximal aspect of the medial lip of linea aspera
A: Adduct, IR, and weak flexion of hip joint
N: Obturator nerve (L2, L3, L4)
Adductor magnus
O: Adductor part (AD) – ischiopubic ramus
Hamstring part (HM) – ischial tuberosity
I: AD – Gluteal tuberosity, linea aspera, medial supracondylar line
HM – adductor tubercle and supracondylar line
A: AD: Adduct, IR, and weak flexion of hip joint
HM: Extend hip joint
N: AD - obturator (L2, L3, L4)
HM - sciatic nerve (tibial division) (L4)
Gracilis
O: Inferior ramus of pubis
I: Medial surface of proximal shaft of the tibia at the pes anserine
A: Adduct hip joint; flexion of knee and IR flexed knee
N: Obturator nerve (L2, L3)
Gluteus maximus
O: External surface of ilium posterior to the posterior gluteal line, posterior surface of lower sacrum and coccyx, sacrotuberous ligament
I: posterior aspect of iliotibial tract of fascia lata and gluteal tuberosity of proximal femur
A: Extension and ER of hip joint; lateral stabilization of hip and knee joints
N: inferior gluteal nerve (L5, S1, S2)
Gluteus medius
O: External surface of ilium between anterior and posterior gluteal lines, just below the iliac crest
I: Lateral surface of the greater trochanter
A: Open chain, all fibers: abduct hip joint
Closed chain, all fibers: holds pelvis secure over stance leg and prevents pelvic drop on the opposite swing side during walking
Anterior fibers: IR and flex hip
Posterior fibers: ER and extend hip
N: Superior gluteal nerve (L4, L5, S1)
Gluteus minimus
O: External surface of ilium between inferior and anterior gluteal lines
I: Anterior aspect of the greater trochanter
A: Abduct, IR, and flex the hip. Stabilize pelvis during unilateral stance
N: superior gluteal nerve (L4, L5, S1)
Tensor fascia latae (TFL)
O: Anterior superior iliac spine, iliac crest posterior to the ASIS
I: Iliotibial tract of facia lata
A: Closed chain: Stabilize the knee in extension
Open chain: Abduct, IR, and flex hip joint
N: Superior gluteal nerve (L4, L5,S1)
Piriformis
O: Anterior surface of sacrum between anterior sacral foramina and sacrotuberous ligament
I: Superior border of greater trochanter of femur
A: ER of extended hip joint; abduct flexed hip joint
N: Nerve to piriformis (branches from anterior rami of (S1, S2) of the sacral plexus
Obturator internus
O: Deep surface of obturator membrane and surrounding bone of the internal border of the obturator foramen
I: Medial side of greater trochanter of femur
A: ER of extended hip joint; abduct flexed hip joint
N: nerve to obturator internus (L5, S1)
Gemellus superior
O: Ischial spine
I: Medial side of the greater trochanter of femur with obturator internus tendon
A: ER of extended hip joint; abduct flexed hip joint
N: Nerve to obturator internus (L5, S1)
Gemellus inferior
O: Ischial tuberosity
I: Medial side of the greater trochanter of femur with obturator internus tendon
A: ER of extended hip joint; abduct flexed hip joint
N: Nerve to quadratus femoris (L5, S1)
Quadratus femoris
O: Lateral aspect of the ischial tuberosity
I: Quadrate tubercle on the intertrochanteric crest of the proximal femur between the greater and lesser trochanters
A: ER of hip joint
N: Nerve to qaudratus femoris (L5, S1)
Obturator externus
O: External surface of obturator membrane and adjacent rami of pubis and ischium
I: Trochanteric fossa of femur
A: ER of hip joint
N: Obturator nerve (posterior division) (L3, L4)
Biceps Femoris
O: Long head – Ischial tuberosity
Short head – Distal aspect of the lateral lip of linea aspera
I: Lateral side of the head of the fibula
A: All heads: Flex and weak ER of knee joint;
Long head: Extend and ER of hip joint
N: Long head: Sciatic (tibial branch): L5,S1,S2
Short head: Sciatic (peroneal branch): L5,S1,S2
Semitendinosus
O: Ischial tuberosity
I: Medial surface of proximal tibia at the pes anserine tendon
A: Flex and IR flexed knee, extend and assist IR of hip, tilt the pelvic posteriorly
N: Sciatic nerve (tibial branch) (L5, S1, S2)
Semimembranosus
O: Ischial tuberosity
I: Posterior surface of medial tibial condyle (some slips into oblique popliteal ligament inserting on lateral condyle)
A: Flex and IR flexed knee, extend and assist IR of hip, tilt the pelvic posteriorly
N: Sciatic nerve (tibial branch) (L5, S1, S2)
Tibialis anterior
O: Lateral condyle of tibia; proximal, lateral surface of tibia and interosseous membrane
I: Medial and inferior surfaces of medial cuneiform and adjacent surfaces on base of 1st metatarsal
A: Dorsiflexion of foot at the ankle joint; inversion of foot; dynamic support of the medial arch of
foot
N: Deep (peroneal) fibular nerve (L4, L5)
Extensor hallucis longus
O: Middle one-half of medial surface of fibula and adjacent surface of interosseous membrane
I: Dorsal surface of base of distal phalanx of great toe
A: Extension of the great toe; dorsiflexion of foot at the ankle; invert the foot
N: Deep fibular (peroneal) nerve (L5, S1)
Extensor digitorum longus
O: Proximal one-half of medial surface of fibula, interosseous membrane and lateral tibial condyle
I: Bases of distal and middle phalanges of lateral four toes via dorsal digital expansion
A: extension of lateral four toes and dorsiflexion of foot (with some eversion)
N: Deep fibular (peroneal) nerve (L5, S1)
Extensor digitorum brevis (The portion to the great toe is the Extensor Hallicus Brevis)
O: Superolateral surface of the calcaneous
I: Base of proximal phalanx of great toe and lateral sides of the tendons of extensor digitorum
longus of 2nd to 4th toes
A: Extension of metatarsophalangeal and IP joints of great toe and extension of at 2nd to 4th toes
N: Deep fibular (peroneal) (L4, L5, S1)
Gastrocnemius
O: Medial head – posterior surface of distal femur just superior to medial condyle
Lateral head – upper posterolateral surface of lateral femoral condyle
I: Posterior surface of calcaneous via calcaneal tendon
A: Plantarflexion at the ankle and flexion at the knee
N: Tibial nerve (S1, S2)
Soleus
O: Soleal line and medial border of the tibia; proximal, posterior aspect of the fibula head and adjacent surfaces of neck and proximal shaft; tendinous arch between tibial and fibular attachment
I: Posterior surface of calcaneous via calcaneal tendon
A: Plantarflexion at the ankle
N: tibial nerve (S1, S2)
Plantaris
O: Inferior part of lateral supracondylar line of femur and oblique popliteal ligament of knee
I: Posterior surface of calcaneous via calcaneal tendon
A: weak plantar flexion of ankle, weak flexion of the knee
N: Tibial nerve (S1, S2)
Popliteus
O: Lateral surface of the lateral femoral condyle and lateral meniscus
I: Posterior surface of proximal tibial, superior to soleal line
A: stabilizes knee joint (resists lateral rotation of tibia on femur); unlocks knee joint (laterally
rotates femur on fixed tibia or medially rotates the tibia on a fixed femur), weak knee flexion
N: Tibial nerve (L4, L5, S1)
Flexor hallicus longus
O: Middle half of the posterior surface of fibula and adjacent interosseous membrane
I: Plantar surface of distal phalanx of great toe
A: flexion of great toe (at MTP and IP joints); Weak plantar flexion of ankle; Invert the foot
N: tibial nerve (S2, S3)
Flexor digitorum longus
O: Middle portion of the medial side of posterior surface of the tibia
I: Plantar surfaces of bases of distal phalanges of the lateral four toes
A: flexion of lateral four toes at MTP and IP joints; Weak plantar flexion of the ankle; invert the foot
N: Tibial nerve (S2, S3)
Tibialis Posterior
O: Posterior surfaces of interosseous membrane and adjacent regions of tibia and fibula, inferior to the soleal line
I: Primarily to tuberosity of navicular and adjacent region of medial cuneiform; some tendinous attachment to the MT bases 2-4 and other tarsal bones
A: Inversion and plantarflexion of the foot at TCJ; support medial arch of foot during walking
N: Tibial nerve (L4, L5)
Peroneus (fibularis) longus
O: Proximal two-thirds of the lateral surface of the fibula, head of fibula
I: Base of the first metatarsal and medial cuneiform
A: Eversion of foot, weak plantarflexion; support arches of foot
N: Superficial fibular nerve (L5, S1, S2)
Peroneus (fibularis) brevis
O: Distal two-thirds of the lateral surface of shaft of fibula
I: Tuberosity at the 5th metatarsal
A: Eversion of the foot and weak plantarflexion of the ankle
N: Superficial fibular nerve (L5, S1, S2)
Peroneus (fibularis) tertius
O: Distal part of medial surface of fibula
I: Dorsomedial surface of base of 5th metatarsal
A: dorsiflexion and eversion of the foot
N: deep fibular nerve (L5, S1)
Abductor Hallicus (1st Layer)
O:Medial process of calcaneus and plantar aponeurosis
I: Proximal phalanax of the first toe (medial surface) and medial sesamoid bone
A: Abduct the first toe (MTP joint) and assist to flex the first toe
N: Medial plantar nerve from the tibial nerve (S2, S3)
Flexor digitorum brevis (1st Layer)
O: Medial process of calcaneal tuberosity and plantar aponeurosis
I: Sides of plantar surface of middle phalanges of 2nd to 5th toes
A: Flexion of lateral four toes at proximal interphalangeal joint
N: medial plantar nerve from the tibial nerve (S2, S3)
Abductor digiti minimi (1st layer)
O: lateral and medial process of calcaneal tuberosity and plantar aponeurosis
I: Lateral side of base of proximal phalanx of little toe
A: Abduction and flexion of the 5th toe at the metatarsophalangeal joint
N: Lateral plantar nerve from the tibial nerve (S2, S3)
Quadratus plantae (2nd layer)
O: Medial surface of calcaneus and lateral process of calcaneal tuberosity
I: Lateral side of tendon of flexor digitorum longus
A: Assist flexor digitorum longus in flexing 2nd to 5th toes, changing the angle of force application to be more linear
N: Lateral plantar nerve from tibial nerve (S2, S3)
Lumbricales (2nd layer)
O: Tendons of flexor digitorum longus
I: Medial slips into extensor hoods of 2nd to 5th toes
A: Flexion of metatarsophalangeal joint and extension of interphalangeal joints of toes 2-5
N: 1st lumbrical – medial plantar nerve from the tibial nerve (S2, S3)
2nd to 4th lumbrical - lateral plantar nerve from the tibial nerve (S2, S3)
Flexor hallicus brevis (3rd layer)
O: Plantar surface of the cuboid, and lateral cuneiforms; tendon of the tibialis posterior
I: Lateral and medial sides of base of proximal phalanx of the great toe via sesamoids
A: Flexion of the metatarsophalangeal joint of the great toe
N: Medial plantar nerve from tibial nerve (S2, S3)
Adductor hallicus (3rd layer)
O: Transverse head – ligaments associated with metatarsophalangeal joints of lateral three toes
Oblique head – bases of 2nd to 4th metatarsals
I: Lateral side of base of proximal phalanx of great toe
A: Adduction of the great toe at metatarsophalangeal joint and maintain transverse arch, weak flexion
N: lateral plantar nerve from tibial nerve (S2, S3)
Flexor digiti minimi brevis (3rd layer)
O: Base of the 5th metatarsal and related sheath of fibularis longus tendon
I: Lateral side of base of proximal phalanx of little toe
A: Flexion of little toe at the metatarsophalangeal joint
N: Lateral plantar nerve from tibial nerve (S2, S3)
Dorsal interossei (4th layer) (4 muscles – bipennate muscles)
O: Sides of adjacent metatarsals
I: Extensor hoods and bases of proximal phalanges of 2nd to 4th toes
First: Medial surface of proximal phalanx of 2nd toe
Second-fourth: Lateral surfaces of proximal phalanx of 2nd-4th toes
A: Open Chain: Abduction of 2nd to 4th toes at metatarsophalangeal joint; flexion of the metatarsalphalangeal joint and extension of the interphalangeal joint
Closed Chain: resists extension of metatarsophalangeal joints and resist flexion of interphalangeal joint
N: Lateral plantar nerve from tibial nerve (S2, S3)
1st and 2nd interossei may also have dual innervation by deep fibular nerve
Plantar interossei (4th layer) (3 muscles – unipennate)
O: Medial sides of metatarsals of 3rd to 5th toes
I: extensor hoods and bases of proximal phalanges of 3rd to 5th toes on medial side
A: Open Chain: Adduction of 3rd to 5th toes at metatarsophalangeal joint; flexion of the metatarsalphalangeal joint and extension of the interphalangeal joint
Closed Chain: resists extension of metatarsophalangeal joints and resist flexion of interphalangeal joint
N: lateral plantar nerve from tibial nerve (S2, S3)
