Anatomy OINAS (UNIT 1)

Gluteus Maximus Origin

Origin: Posterior ilium - posterior gluteal line; dorsal sacrum and coccyx; sacrotuberous ligament

Gluteus Maximus Insertion

Insertion: Most fibers: to Gerdy's tubercle via IT band; some fibers to gluteal tuberosity

Gluteus Maximus Innervation

Innervation: Inferior gluteal nerve (L5, S1, S2)

Gluteus Maximus Action

Action: Extends hip; assists in external rotation; steadies thigh and assists in rising from sitting

Gluteus Medius Origin

Origin: Between anterior and posterior gluteal lines of ilium

Gluteus Medius Insertion

Insertion: Lateral greater trochanter of femur

Gluteus Medius Innervation

Innervation: Superior gluteal nerve (L5, S1)

Gluteus Medius Action

Action: Abducts and internally rotates hip; keep pelvis level during ipsilateral weight bearing

Gluteus Minimus Origin

Origin: Between anterior and inferior gluteal lines of ilium

Gluteus Minimus Insertion

Insertion: Anterior greater trochanter of femur

Gluteus Minimus Innervation

Innervation: Superior gluteal nerve (L5, S1)

Gluteus Minimus Action

Action: Abducts and internally rotates hip; keep pelvis level during ipsilateral weight bearing

Tensor Fasciae Latae Origin

Origin: ASIS; anterior iliac crest

Tensor Fasciae Latae Insertion

Insertion: to Gerdy's tubercle via IT band

Tensor Fasciae Latae Innervation

Innervation: Superior gluteal nerve (L5, S1)

Tensor Fasciae Latae Action

Action: Abducts and internally rotates hip; keep pelvis level during ipsilateral weight bearing; assists in hip flexion

Piriformis Origin

Origin: Anterior sacrum; sacrotubrous ligament

Piriformis Insertion

Insertion: Superior greater trochanter of femur

Piriformis Innervation

Innervation: Nerve to piriformis (S1, S2)

Piriformis Action

Action: Externally rotates extended hip; abducts flexed hip; steady femoral head in acetabulum

Superior gemellus Origin

Origin: Ischial spine

Superior gemellus Insertion

Insertion: Medial greater trochanter (trochanteric fossa) of femur

Superior gemellus Innervation

Innervation: Nerve to obturator internus (L5, S1)

Superior gemellus Action

Action: Externally rotates extended hip; abducts flexed hip; steady femoral head in acetabulum

Obturator internus Origin

Origin: Inner obturator membrane; surrounding bones

Obturator internus Insertion

Insertion: Medial greater trochanter (trochanteric fossa) of femur

Obturator internus Innervation

Innervation: Nerve to obturator internus (L5, S1)

Obturator internus Action

Action: Externally rotates extended hip; abducts flexed hip; steady femoral head in acetabulum

Inferior gemellus Origin

Origin: Ischial tuberosity

Inferior gemellus Insertion

Insertion: Medial greater trochanter (trochanteric fossa) of femur

Inferior gemellus Innervation

Innervation: Nerve to quadratus femoris (L5, S1)

Inferior gemellus Action

Action: Externally rotates extended hip; abducts flexed hip; steady femoral head in acetabulum

Obturator externus Origin

Origin: Outer obturator membrane and surrounding margins of obturator foramen

Obturator externus Insertion

Insertion: Trochanteric fossa of femur

Obturator externus Innervation

Innervation: Obturator nerve (L3, L4)

Obturator externus Action

Action: Externally rotates hip; steadies femoral head in acetabulum

Quadratus femoris Origin

Origin: Lateral Ischial tuberosity

Quadratus femoris Insertion

Insertion: Quadrate tubercle + area inferior to inter trochanteric crest of femur

Quadratus femoris Innervation

Innervation: Nerve to quadratus femoris (L5, S1)

Quadratus femoris Action

Action: Externally rotates hip; steadies femoral head in acetabulum

Pectineus Origin

Origin: Superior ramus of pubis

Pectineus Insertion

Insertion: Pectineal line + area inferior to lesser trochanter

Pectineus Innervation

Innervation: Femoral nerve (L2, L3); sometimes obturator nerve (L4)

Pectineus Action

Action: Adducts and flexes hip; assists with internal rotation of hip

Iliacus Origin

Origin: Iliac crest + iliac fossa; ala of sacrum; anterior SI ligaments

Iliacus Insertion

Insertion: Tendon of psoas major; lesser trochanter of femur + slightly distal to it

Iliacus Innervation

Innervation: Femoral nerve (L2, L3)

Iliacus Action

Action: Flexes hip; stabilizes hip joint

Psoas major Origin

Origin: Sides of T12-L5 vertebrae and discs; lumbar transverse processes

Psoas major Insertion

Insertion: Lesser trochanter of femur

Psoas major Innervation

Innervation: Anterior rami of L1, L2, L3

Psoas major Action

Action: Flexes hip; stabilizes hip joint

Psoas minor Origin

Origin: Sides of T12-L1 vertebrae and discs

Psoas minor Insertion

Insertion: Pectineal line of pubis; iliopubic eminence

Psoas minor Innervation

Innervation: Anterior rami L1, L2

Psoas minor Action

Action: Weak trunk flexor

Sartorius Origin

Origin: ASIS; superior part of notch inferior to it

Sartorius Insertion

Insertion: Pes anserinus

Sartorius Innervation

Innervation: Femoral nerve (L2, L3)

Sartorius Action

Action: Flexes, abducts, and externally rotates hip; flexes knee; medially rotates leg during knee flexion)

Rectus femoris Origin

Origin: AIIS; ilium superior to acetabulum

Rectus femoris Insertion

Insertion: Quadriceps tendon to base of patella, apex of patella to tibial tuberosity via patella ligament

Rectus femoris Innervation

Innervation: Femoral nerve (L2, L3, L4)

Rectus femoris Action

Action: Extends knee; helps iliopsoas flex hip, steadies hip

Vastus lateralis Origin

Origin: Greater trochanter + lateral lip of linea aspera of femur

Vastus lateralis Insertion

Insertion: Quadriceps tendon to base of patella, apex of patella to tibial tuberosity via patella ligament

Vastus lateralis Innervation

Innervation: Femoral nerve (L2, L3, L4)

Vastus lateralis Action

Action: Extends knee

Vastus medialis Origin

Origin: Inter trochanteric line + medial lip of linea aspera of femur

Vastus medialis Insertion

Insertion: Quadriceps tendon to base of patella, apex of patella to tibial tuberosity via patella ligament

Vastus medialis Innervation

Innervation: Femoral nerve (L2, L3, L4)

Vastus medialis Action

Action: Extends knee

Vastus intermedius Origin

Origin: Anterior + lateral shaft of femur

Vastus intermedius Insertion

Insertion: Quadriceps tendon to base of patella, apex of patella to tibial tuberosity via patella ligament

Vastus intermedius Innervation

Innervation: Femoral nerve (L2, L3, L4)

Vastus intermedius Action

Action: Extends knee

Adductor longus Origin

Origin: Body of pubis inferior to pubic crest

Adductor longus Insertion

Insertion: Middle third of linea aspera of femur

Adductor longus Innervation

Innervation: Obturator nerve (ant. division) (L2, L3, L4)

Adductor longus Action

Action: Adducts hip

Adductor brevis Origin

Origin: Body + inferior ramus of pubis

Adductor brevis Insertion

Insertion: Pectineal line + proximal linea aspera of femur

Adductor brevis Innervation

Innervation: Obturator nerve (ant. division) (L2, L3, L4)

Adductor brevis Action

Action: Adducts hip; limited hip flexion

Adductor Magnus (adductor) Origin

Origin: Inferior ramus of pubis; Ischial ramus

Adductor Magnus (adductor) Insertion

Insertion: Gluteal tuberosity + linea aspera + medial supracondylar line of femur

Adductor Magnus (adductor) Innervation

Innervation: Obturator nerve (post. division) (L2, L3, L4)

Adductor Magnus (adductor) Action

Action: Adducts and flexes hip

Adductor magnus (hamstring) Origin

Origin: Ischial tuberosity

Adductor magnus (hamstring) Insertion

Insertion: Adductor tubercle of femur

Adductor magnus (hamstring) Innervation

Innervation: Tibial nerve (L4)

Adductor magnus (hamstring) Action

Action: Adducts and extends hip

Gracilis Origin

Origin: Body + inferior ramus of pubis

Gracilis Insertion

Insertion: Pes anserinus

Gracilis Innervation

Innervation: Obturator nerve (L2, L3)

Gracilis Action

Action: Adducts hip; flexes knee; helps internally rotates leg

Semitendinosus Origin

Origin: Ischial tuberosity

Semitendinosus Insertion

Insertion: Pes anserinus

Semitendinosus Innervation

Innervation: Tibial division of sciatic nerve (L5, S1, S2)

Semitendinosus Action

Action: Extends hip; flexes knee; internally rotates leg during knee flexion