Lower Extremity- Origin, Insertion, Action, Nerve Supply

Iliacus- Origin

1. Iliac Fossa

2. Sacrum

Iliacus- Insertion

Lesser Trochanter of the Femur

Iliacus- Action

1. Flexion of femur at hip joint

2. Helps maintain posture (integrity of spine)

Iliacus-Nerve Supply

Femoral nerve (L2-L4)

Psoas Major- Origin

Transverse processes and bodies of lumbar vertebrae (T12-L5)

Psoas Major- Insertion

Lesser trochanter of femur

Psoas Major- Action

1. Flexion of femur at hip joint

2. Helps maintain posture (integrity of spine)

Psoas Major- Nerve Supply

Femoral Nerve

Psoas Minor- Origin

Bodies/ T12-L1

Psoas Minor- Insertion

Iliopubic eminence/ Pubis

Psoas Minor- Action

Flexion of pelvic bone (upward movement)

Psoas Minor- Nerve Supply

L1 (sometimes L2)

Sartorius- Origin

Anterior superior iliac spine (ASIS)

Sartorius- Insertion

Superior Medial shaft of tibia

Sartorius- Action

1. Abducts & laterally rotates femur

2. Medially rotates leg

3. Assists flexion hip & knee when both are carried out

Sartorius- Nerve Supply

Femoral nerve

Rectus Femoris- Origin

1. Anterior Inferior Iliac Spine

2. Acetabulum/pelvic bone

Rectus Femoris- Insertion

Base/Patella

Rectus Femoris- Action

1. Extends leg at knee

2. Flexion at hip

3. Tonus of muscles play role in strengthening knee

Rectus Femoris- Nerve Supply

Femoral nerve

Vastus Lateralis- Origin

1. Greater trochanter/femur

2. Intertrochanteric line/femur

3. Lina aspera/femur

Vastus Lateralis- Insertion

Base/Patella

Vastus Lateralis- Action

1. Extends leg at knee

2. Tonus of muscles play role in strengthening knee

Vastus Lateralis- Nerve Supply

Femoral Nerve

Vastus Medialis- Origin

1. Linea aspera/femur

2. Intertrochanteric line/ femur

Vastus Medialis- Insertions

Base/patella

Vastus medialis- Action

1. Extends leg at knee

2. Tonus of muscles play role in strengthening knee

Vastus medialis- Nerve Supply

Femoral Nerve

Vastus Intermedius- Origin

Antero-lateral aspect of femur

Vastus Intermedius- Insertion

Base/patella

Vastus Intermedius- Action

1. Extends leg at knee

2. Tonus of muscles play role in strengthening knee

Vastus Intermedius- Nerve Supply

Femoral Nerve

Gracilis- Origin

1. Ramus/ischium

2. Inferior ramus/pubis

Gracilis-Insertion

Superior medial shaft/tibia

Gracilis- Action

1. Flexion/leg

2. Adducts femur

Gracilis- Nerve Supply

Obturator Nerve

Pectineus- origin

superior rami (pubis pectin)/pubis

Pectineus- insertion

1. Pectineal line/femur

2. linea aspera/femur

Pectineus- action

1. adducts femur

2. flexion/femur at hip joint

Pectineus- nerve supply

Femoral nerve and Obturator nerve

Adductor Longus- origin

Superior ramus/pubis

Adductor Longus-insertion

Linea aspera/femur

Adductor Longus- action

Adducts femur

Adductor Longus- nerve supply

Obturator nerve

Adductor Brevis-origin

Inferior ramus/pubis

Adductor Brevis-insertion

1. Pectineal line/femur

2. Linea aspera/femur

Adductor Brevis-action

Adducts femur

Adductor Brevis- nerve supply

Obturator nerve

Adductor Magnus- origin

Rami/ischium & pubis

Adductor Magnus- insertion

1. Linea aspera/femur

2. Adductor tubercle/femur

Adductor Magnus-action

1. Adducts femur

2. Extends femur @ hip joint

Adductor Magnus- nerve supply

Obturator nerve and Sciatic nerve

Tensor Fascia Lata- origin

Crest/ilium

Tensor Fascia Lata-insertion

Iliotibial tract

Tensor Fascia Lata-action

1. Flexes, abducts and medially rotates femur

2. Helps stabilize knee

Tensor Fascia Lata-nerve supply

Superior Gluteal nerve

Gluteus Maximus-origin

1. Posterior gluteal line/ilium

2. Sacrum &coccyx

3. Posterior ligaments of SI joint

Gluteus Maximus-insertion

1. Gluteal tuberosity/femur

2. Iliotibial tract

Gluteus Maximus-action

1. Extends &laterally rotates femur (for great strength when going form sitting to standing)

2. Stabilizes knee

3. Helps stabilize pelvic bone

Gluteus Maximus-nerve supply

Inferior Gluteal nerve

Gluteus medius- origin

External surface/ilium (between post and anterior gluteal lines)

Gluteus medius- insertion

Greater trochanter/femur

Gluteus medius-action

1. Abducts femur

2. Medially rotates femur

3. Helps steady pelvic bone when opp. foot is raised off ground

Gluteus medius- nerve supply

Superior Gluteal nerve

Gluteus Minimus- origin

External surface/ilium (between post and anterior gluteal lines)

Gluteus Minimus- insertion

Greater trochanter/femur

Gluteus Minimus-action

1. Abducts femur

2. Medially rotates femur

3. Helps steady pelvic bone when opp. foot is raised off ground

Gluteus Minimus- nerve supply

Superior Gluteal nerve

Piriformis- origin

Anterior surface/sacrum

Piriformis-insertion

Greater trochanter/femur

Piriformis-action

Laterally rotates femur

Piriformis- nerve supply

S1, S2

Superior Gemellus-origin

Spine/ischium

Superior Gemellus-insertion

Greater trochanter/femur

Superior Gemellus-action

laterally rotates femur

Superior Gemellus-nerve supply

L4, L5, S1, S2

Obturator Internus- origin

Internal surface/obturator membrane

Obturator Internus- insertion

Greater trochanter/femur

Obturator Internus- action

laterally rotates femur

Obturator Internus-nerve supply

L4, L5, S1, S2

Inferior Gemellus- origin

Ischial tuberosity

Inferior Gemellus-insertion

Greater trochanter/femur

Inferior Gemellus-action

laterally rotates femur

Inferior Gemellus-nerve supply

L4, L5, S1, S2

Obturator Externus-origin

External surface/obturator membrane

Obturator Externus- insertion

Trochanteric fossa/femur

Obturator Externus- action

laterally rotates femur

Obturator Externus-nerves supply

Obturator nerve

Quadratus Femoris- origin

Ischial tuberosity

Quadratus Femoris- insertion

Quadrate tubercle/femur

Quadratus Femoris- action

laterally rotates femur

Quadratus Femoris- nerve supply

L4, L5, S1, S2

Semitendinosus- origin

Ischial tuberosity

Semitendinosus-insertion

1. Medial condyle/tibia

2. Proximal post. shaft/tibia

Semitendinosus-action

1. Flexion/leg at knee joint

2. Stabilize hip

3. Extend femur

4. Medially rotates leg

Semitendinosus- nerve supply

Sciatic nerve

Semimembranosus- origin

Ischial tuberosity

Semimembranosus-insertion

Medial condyle/tibia

Semimembranosus- action

1. Flexion/leg at knee joint

2. Stabilize hip

3. Extend femur

4. Medially rotates leg

Semimembranosus- nerve supply

Sciatic nerve