Exam 4 lower body and Abs

Iliopsoas group

Psoas major + Iliacus

Anterior

Psoas major

Psoas major - Action

Flexes thigh; ipsilateral lateral flexion of vertebral column

Psoas major - Innervation

L1-L3

Psoas major - Origin

Lumbar vertebrae

Psoas major - Insertion

Lesser trochanter

Anterior

Iliacus

Iliacus - Action

Flexes thigh

Iliacus - Innervation

Femoral nerve

Iliacus - Origin

Iliac fossa

Iliacus - Insertion

Lesser trochanter

Anterior

Psoas minor

Psoas minor - Action

Assists trunk flexion

Psoas minor - Innervation

L2-L3

Posterior

Gluteus maximus

Gluteus maximus - Action

Extends thigh (especially from flexed position), laterally rotates, abducts

Gluteus maximus - Innervation

Inferior gluteal nerve

Gluteus maximus - Origin

Dorsal ilium, sacrum, coccyx

Gluteus maximus - Insertion

Gluteal tuberosity; iliotibial tract

Posterior

Gluteus medius

Gluteus medius - Action

Abducts thigh; medially rotates; stabilizes pelvis

Gluteus medius - Innervation

Superior gluteal nerve

Gluteus medius - Origin

Lateral ilium

Gluteus medius - Insertion

Greater trochanter

Posterior

Gluteus minimus

Gluteus minimus - Action

Abducts thigh; medially rotates; stabilizes pelvis

Gluteus minimus - Innervation

Superior gluteal nerve

Gluteus minimus - Origin

Lateral ilium

Gluteus minimus - Insertion

Greater trochanter

Deep Gluteal

Piriformis

Piriformis - Action

Abducts & laterally rotates thigh

Piriformis - Innervation

S1, S2, L5

Piriformis - Insertion

Greater trochanter

Deep Gluteal

Gemellus superior

Gemellus superior - Action

Laterally rotates thigh

Gemellus superior - Innervation

L5, S1

Deep Gluteal

Obturator internus

Obturator internus - Action

Abducts & laterally rotates thigh

Obturator internus - Innervation

L5, S1

Deep Gluteal

Gemellus inferior

Gemellus inferior - Action

Laterally rotates thigh

Gemellus inferior - Innervation

L5, S1

Deep Gluteal

Obturator externus

Obturator externus - Action

Laterally rotates thigh

Obturator externus - Innervation

Obturator nerve

Deep Gluteal

Quadratus femoris

Quadratus femoris - Action

Laterally rotates thigh

Quadratus femoris - Innervation

L5, S1

Anterior Thigh

Sartorius

Sartorius - Action

Flexes thigh & knee; abducts; laterally rotates; "cross-legged" position

Sartorius - Innervation

Femoral nerve

Sartorius - Origin

ASIS

Sartorius - Insertion

Medial proximal tibia

Anterior Thigh

Vastus medialis

Vastus medialis - Action

Extends leg

Vastus medialis - Innervation

Femoral nerve

Vastus medialis - Origin

Linea aspera, intertrochanteric line

Vastus medialis - Insertion

Patella; tibial tuberosity

Anterior Thigh

Vastus lateralis

Vastus lateralis - Action

Extends knee; stabilizes patella

Vastus lateralis - Innervation

Femoral nerve

Vastus lateralis - Origin

Intertrochanteric line; proximal linea aspera

Vastus lateralis - Insertion

Patella; tibial tuberosity

Anterior Thigh

Vastus intermedius

Vastus intermedius - Action

Extends leg

Vastus intermedius - Innervation

Femoral nerve

Vastus intermedius - Origin

Anterior/lateral femur

Vastus intermedius - Insertion

Patella; tibial tuberosity

Anterior Thigh

Rectus femoris

Rectus femoris - Action

Extends knee; flexes thigh

Rectus femoris - Innervation

Femoral nerve

Rectus femoris - Origin

AIIS

Rectus femoris - Insertion

Patella; tibial tuberosity

Medial Thigh

Adductor longus

Adductor longus - Action

Adducts, flexes, medially rotates thigh

Adductor longus - Innervation

Obturator nerve

Medial Thigh

Adductor brevis

Adductor brevis - Action

Adducts, flexes, medially rotates thigh

Adductor brevis - Innervation

Obturator nerve

Medial Thigh

Adductor magnus

Adductor magnus - Action

Adducts, flexes, medially rotates thigh

Adductor magnus - Innervation

Obturator + sciatic nerves

Adductor magnus - Origin

Ischial tuberosity; ischial ramus; inferior pubic ramus

Adductor magnus - Insertion

Linea aspera; adductor tubercle

Medial Thigh

Pectineus

Pectineus - Action

Adducts, flexes, medially rotates thigh

Pectineus - Innervation

Femoral nerve

Medial Thigh

Gracilis

Gracilis - Action

Adducts thigh; flexes thigh; flexes & medially rotates leg

Gracilis - Innervation

Obturator nerve

Gracilis - Origin

Pubis (body & inferior ramus)

Gracilis - Insertion

Medial proximal tibia (pes anserinus)

Posterior Thigh

Biceps femoris

Biceps femoris - Action

Extends thigh; flexes knee

Biceps femoris - Innervation

Long head: sciatic; Short head: common fibular

Biceps femoris - Origin

Long head: ischial tuberosity; Short head: linea aspera

Biceps femoris - Insertion

Head of fibula; lateral tibial condyle

Posterior Thigh

Semitendinosus

Semitendinosus - Action

Extends thigh; flexes knee

Semitendinosus - Innervation

Sciatic nerve