Lower Extremity Muscles Flashcards
Sartorius
O. Anterior superior iliac spine
I. upper medial shaft of tibia
A. assists in all of the following: flexion of femur, abduction of femur, lateral rotation of femur, flexion of knee, medial rotation of tibia when knee is flexed and foot is unweighted
N. Femoral n (L2, 3)
Psoas Major and Iliacus (Iliopsoas)
O. Psoas Major: Lumbar vertebrae L1-5- transverse processes. T12-L5 vertebrae- bodies and intervertebral discs
O. Iliacus: Iliac fossa of ilium
I. Lesser tronchanter of femur
A. Flexion of femur. Psoas major: flexion of trunk – lumbar spine. Assists lateral flexional of trunk – lumbar spine
N. Psoas major: L2, 3 spinal ns
Iliacus: femoral n (L2, 3)
Rectus Femoris
O. Anterior inferior iliac spine. Ilium at upper rim of acetabulum
I. Patella. Tibial tuberosity via patellar ligament
A. Extension of knee. Assists flexion of femur
N. Femoral n (L2,3,4)
Vastus Medialis
O. Linea aspera of femur. Intertrochanteric line of femur
I. Patella. Tibial tuberosity via patellar ligament.
A. Extension of knee
N. Femoral n (L2,3,4)
Vastus lateralis
O. Linea aspera of femur. Greater trochanter of femur
I. Patella. Tibial tuberosity via patellar ligament
A. Extension of knee
N. Femoral n. (L2,3,4)
Vastus intermedius
O. Anterior and lateral femoral shaft
I. Patella. Tibial tuberosity via patellar ligament
A. Extension of knee
N. Femoral n (L2,3,4)
Pectineus
O. Superior ramus of anterior pubis
I. Pectineal line of femur, inferior to lesser trochanter
A. Felxion of femur, adduction of femur, assists medial rotation of femur
N. Femoral n. (L2,3)
Adductor Longus
O. Anterior pubis- body - body, inferior to pubic crest
I. linea aspera of femur - middle one third
A. adduction of femur, assists flexion of femur
N. Obturator n (L2,3,4)
Adductor Brevis
O. Anterior pubis - body and inferior ramus
I. Linea aspera of femur - proximal part. Pectineal line of femur
A. adduction of femur, assists flexion of femur
N. Obturator n (L2,3,4)
Adductor Magnus
O. Anterior head: inferior ramus of pubis
Posterior head: ischail tuberosity. Ramus of ischium
I. Anterior head: linea aspera of femur
Posterior head: adductor tubercle of femur
A. Adduction of femur.
Anterior head: assists flexion of femur, assists medial rotation of femur
Posterior head: assists extension of femur, assists lateral rotation of femur.
N. Anterior head: obturator n (L2,3,4)
Posterior head: Sciatic n (L4)
Gracilis
O. Inferior ramus of anterior pubis
I. medial proximal tibia
A. adduction of femur, assists flexion of knee, assists medial rotation of tibia when knee is flexed
N. Obturator n. (L2,3)
Glueteus Maximus
O. Posterior sacrum. Ilium (via sacrotuberous ligament). Posterior (superior) gluteal line of ilium.
I. Gluteal tuberosity of femur. Iliotibial tract (attaching to lateral condyle of tibia)
A. Extension of femur. Lateral rotation of extended hip
N. Inferior gluteal n. (L5, S1, 2)
Gluteus Medius
O. Iliac crest of ilium. Ilium - between posterior (superior) and anterior (middle) gluteal lines
I. Greater trochanter of femur
A. abduction of femur
Anterior fibers: medial rotation of femur
N. superior gluteal n (L5, S1)
Gluteus Minimus
O. Posterior ilium - between anterior (middle) and inferior gluteal lines
I. Anterior surface of greater trochanter of femur
A. Abduction. Medial rotation of femur
N. Superior gluteal n (L5, S1)
Biceps Femoris
O. Long head: ischial tuberosity
Short head: Linea aspera
I. Head of fibula - lateral aspect. Lateral condyle of tibia
A. Flexion of knee. Lateral rotation of tibia when knee is flexed.
Long head: extension of femur
N. Long head: Sciatic n - tibial division (L5, S1, 2)
Short head: Sciatic n - fibular division (L5, S1, 2)
Semitendinosus
O. Ischial tuberosity
I. Anterior proximal tibial shaft
A. Extension of femur. Flexion of knee. Medial rotation of tibia when knee is flexed.
N. Sciatic n - tibial division (L5, S1, 2)
Semimembranosus
O. Ischial tuberosity
I. Posterior medial tibial condyle
A. Extension of femur. Extension of knee. Medial rotation of tibial when knee is flexed
N. Sciatic n - tibial division (L5, S1, 2)
Tibialis Anterior
O. Lateral condyle of tibia. Lateral shfat of tibia, interosseous membrane
I. Base of 1st metatarsal - plantar surface. Medial cuneiform tarsal bone - plantar surface
A. Dorsiflexion of ankle. Inversion of foot
N. Deep fibular n (L4, 5)
Extensor Digitorum Longus
O. Lateral condyle of tibia. Proximal 2/3 of anterior shaft of fibula.
I. Middle and distal phalanges of 4 lateral toes
A. Extension of 4 lateral toes at MP joints. Assists dorsiflexion of ankle
N. Deep fibular n (L5, S1)
Extensor Hallucis Longus
O. Anterior shaft of fibula. Interosseous membrane
I. Base of distal phalanx of the great toe
A. Extension of great toe at IP joint. Extension of great toe at MP joint. Assists dorsiflexion of ankle.
N. Deep fibular n (L5, S1)
Fibularis Tertius (Peroneus Tertius)
O. Anterior distal fibula (with extensor digitorum longus)
I. Base of 5th metatarsal
A. Eversion of foot. Assists dorsiflexion of foot
N. Deep fibular n (L5, S1)
Fibularis Brevis (Peroneus Brevis)
O. Lateral shaft of fibula - lower 2/3
I. Base of 5th metatarsal - lateral surface
A. Eversion of foot. Assists plantar flexion of ankle
N. Superficial fibular n (L5, S1)
Gastrocnemius
O. Medial Head: medial epicondyle of femur.
Lateral Head: lateral epicondyle of femur
I. Calcaneus via calcaneal tendon (tendo Achilles)
A. Plantarflexion of ankle. Assists flexion of knee
N. Tibial n (S1, 2)
Soleus
O. Soleal line of tibia. Posterior head of fibula. Upper shaft of fibula
I. Calcaneus via calcaneal tendon (tendo Achilles)
A. Plantarflexion of ankle
N. Tibial n (S1, 2)
Tibialis Posterior
O. Posterior tibia. Posterior fibula. Interosseous membrane
I. Navicular tarsal bone. Adjacent tarsals and metatarsals on plantar surface
A. Inversion of foot. Assists plantarflexion of ankle
N. Tibial n (L4, 5)
Flexor Digitorum Longus
O. Posterior tibia
I. Distal phalanges of 4 lateral toes - plantar surface
A. Flexion of 4 lateral toes at IP joints. Assists flexion of 4 lateral toes at MP joints. Assists plantarflexion of ankle
N. Tibial n (S2, 3)
Flexor Hallucis Longus
O. Posterior fibula
I. Distal phalanx of great toe - plantar surace
A. Flexion of great toe at MP joint. Flexion of great toe at IP joint. Assists plantarflexion of ankle
N. Tibial n (S2, 3)
Extensor Digitorum Brevis
O. Anterior calcaneus
I. Extensor expansion of 4 medial toes
A. Assists extension of 4 medial toes at MP joints. Assists extension of 4 medial toes at IP joints
N. Deep fibular n (L5, S1)
