Functional Anatomy Lower body

Sartorius

Origin:

-Pelvis: anterior superior iliac spine

Insertion:

-Tibia: proximal part of the medial surface (superomedial shaft of the tibia

Action:

-Hip flexion

-Hip external rotation with abduction

-knee flexion

Innervation:

-Femoral nerve

Rectus Femoris

Origin:

-Pelvis: straight head: anterior inferior iliac spine- reflected head: the grove above the acetabulum

Insertion:

-Proximal border of the patella and through the patellar ligament to the tuberosity of the tibia

Action:

-Knee extension

-hip flexion

-anterior pelvic tilt

Innervation:

-Femoral nerve

Iliacus

Origin:

-Hip bone: iliac fossa

Insertion:

-Femur: distal to the lesser trochanter in common with tendon of psoas major muscle

Action:

-Hip flexion

-Flexing the trunk on femur

-anterior pelvic tilt

Innervation:

-Femoral nerve

Psoas Major

Origin:

-Thoracic vertebrae (T12)

-Lumbar vertebrae (L1-L5)

-Intervertebral discs (T12-L5)

Insertion:

-Femur: lesser trochanter

Action:

-Hip flexion

-flexing the trunk on the femur

-Increase lordosis

-Lateral flexion of the trunk

Innervation:

-Femoral nerve

Pectineus

Origin:

-Pubis: superior ramus of pubis

Insertion:

-Femur: pectineal line of the femur between the lesser trochanter and the linea aspera

Action:

-Hip adduction

Innervation:

-Femoral nerve

Adductor brevis

Origin:

-Pubis: outer surface of the inferior ramus of the pubis

Insertion:

-Femur: distal ⅔ of the pectineal line; medial lip of the linea aspera

Action:

-Hip adduction

-Hip internal rotation

Innervation:

-Obturator nerve

Adductor longus

Origin:

-Pubis: anterior surface of the pubis

Insertion:

-Femur: middle ⅓ of the medial lip of the linea aspera

Action:

-Hip adduction

-hip internal rotation

Innervation:

-Obturator nerve

Adductor magnus

Origin:

-Inferior ramus of pubis and ischial tuberosity

Insertion:

-Femur: medial lip of linea aspera; adductor tubercle

Action:

-Hip adduction

-Hip internal rotation

Innervation:

-Obturator nerve

-Sciatic nerve

Gracilis

Origin:

-Inferior ramus of pubis

Insertion:

-distal to the medial condyle

Action:

-Hip adduction

Innervation:

-Obturator nerve

Gluteus maximus

Origin:

-Hip bone: iliac crest

-sacrum: posterior side

-Hip bone: ala of ilium: posterior side

Insertion:

-Femur: gluteal tuberosity

-Iliotibial band

Action:

-Hip extension

-hip internal rotation

-knee lateral rotation

-pelvic backward rotation

-pelvic medial rotation

-pelvic lateral flexion

Innervation:

-inferior gluteal nerve

Gluteus medius

Origin:

-Hip bone: iliac crest: ala of ilium

Insertion:

-Femur: greater trochanter

Action:

-Hip abduction

-Prevent the pelvis from tilt down on the opposite side on standing on one leg

Innervation:

-Superior gluteal nerve

Gluteus minimus

Origin:

-Ilium: outer surface, between middle and inferior gluteal lines

Insertion:

-Femur: greater trochanter (anterior surface)

Action:

-Hip abduction

-Hip medial rotation

Innervation:

-Superior gluteal nerve

Biceps femoris: LH

Origin:

-Long head: ischeal tuberosity

Insertion:

-Fibula: proximal head

Action:

-Knee flexion

-Hip extension

-Knee external rotation

-Back extension at the hip joint

Innervation:

-Sciatic nerve

Biceps femoris: SH

Origin:

-Short head: femur: linea aspera

Insertion:

-Fibula: proximal head

Action:

-Knee flexion

-Knee external rotation

Innervation:

-Common peroneal nerve

Semitendinosus

Origin:

-Ischial tuberosity

Insertion:

-Under the medial condyle of tibia

Action:

-Knee flexion

-hip extension

-knee internal rotation

-Back extension at the hip joint

Innervation:

-Sciatic nerve

Semimembranosus

Origin:

-Ischial tuberosity

Insertion:

-Medial condyle of tibia (in the posterior side)

Action:

-Knee flexion

-hip extension

-knee internal rotation

-Back extension at the hip joint

Innervation:

-Sciatic nerve

Piriformis

Origin:

-Sacrum: anterior surface of lateral process

-Ilium: gluteal surface

Insertion:

-Femur: greater trochanter (superior border)

Action:

-Hip external rotation

Innervation:

-S1 nerve root

-S2 nerve root

Superior gemellus

Origin:

-ischium: ischial spine

Insertion:

-Femur: greater trochanter (medial surface)

Action:

-Hip external rotation

Innervation:

-L5 nerve root

-S1-S2 Nerve root

Inferior gemellus

Origin:

-Lateral border of ischial tuberosity

Insertion:

-Femur: greater trochanter (medial surface)

Action:

-Hip external rotation

Innervation:

-L4-L5 Nerve root

-S1-S2 Nerve root

Obturator externus

Origin:

-External surface of the obturator membrane

Insertion:

-femur: greater trochanter (posteromedial surface)

Action:

-Hip external rotation

Innervation:

-Obturator nerve

Obturator internus

Origin:

-Internal surface of obturator membrane

-obturator foramen

Insertion:

-Femur: greater trochanter (medial surface)

Action:

-Hip external rotation

Innervation:

-L5 nerve root

-S1-S2 nerve root

Quadratus femoris

Origin:

-Lateral border of ischial tuberosity

Insertion:

-femur: quadrate tubercle (proximal posterior femur)

Action:

-Hip external rotation

Innervation:

-L4-L5 nerve root

-S1-S2 nerve root

Tensor Fascia Latae (TFL)

Origin:

-Outer lip of anterior iliac crest

-anterior superior iliac spine

-fascia lata

Insertion:

-tibia lateral condyle

Action:

-Hip flexion with abduction and medial rotation

-hip abduction

-hip medial rotation

-pelvic tilt anterior and lateral

Innervation:

-Superior gluteal nerve

Vastus Intermedius

Origin:

-Femur: anterior and lateral surface of the body of the femur

Insertion:

-Proximal border of the patella and through the patellar ligament to the tuberosity of the tibia

Action:

-Knee extension

Innervation:

-Femoral nerve

Vastus lateralis

Origin:

-Femur: greater trochanter and the lateral lip of the linea aspera

Insertion:

-Proximal border of the patella and through the patellar ligament to the tuberosity of the tibia

Action:

-Knee extension

Innervation:

-Femoral nerve

Vastus medialis

Origin:

-Femur: medial lip of the linea aspera

Insertion:

-Proximal border of the patella and through the patellar ligament to the tuberosity of the tibia

Action:

-Knee extension

Innervation:

-Femoral nerve

Popliteus

Origin:

-Femur: lateral condyle

-lateral meniscus of the knee joint

Insertion:

-tibia: posterior surface of the body of the tibia

Action:

-knee internal rotation

-knee flexion

-laterally rotates the femur to unlock the knee joint when the tibia is fixed

Innervation:

-Tibial nerve

Gastrocnemius

Origin:

-Femur: lateral and medial epicondyles

Insertion:

-posterior surface of calcaneus via achilles tendon

Action:

-ankle plantar flexion

Innervation:

-Tibial nerve

Soleus

Origin:

-Tibia: Soleal line

-fibula: head+ dorsal surface (upper third)

Insertion:

-posterior surface of calcaneus via achilles tendon

Action:

-ankle plantar flexion

Tibialis Posterior

Origin:

-Fibula: superior ⅔ of posterior surface

-interosseous membrane

-tibia: superior aspect of the posterior surface

Insertion:

-Navicular bone

-Medial cuneiform

-2nd to 4th metatarsals and second cuneiform

Action:

-ankle plantar flexion

-foot inversion

Innervation:

-Tibial nerve

Flexor digitorum longus

Origin:

-Tibia: posterior surface

Insertion:

-bases of the 2nd - 5th distal phalanges

Action:

-Plantar flexion of toes 2-5

Innervation:

-Tibial nerve

Flexor hallucis longus

Origin:

-fibula

Insertion:

-base of distal phalanx of big toe

Action:

-plantar flexion of the great toe

Innervation:

-Tibial nerve

Fibularis longus

Origin:

-Fibula: Upper 1/2 - 2/3 of lateral fibular shaft surface -Proximal head and head of fibula

Insertion:

-Medial cuneiform (plantar/inferior aspect)

-lateral side of 1st metatarsal base

Action:

-Foot Eversion

-Assists in ankle plantar flexion

Fibularis brevis

Origin:

-Fibula: interior (distal) ⅔ of lateral fibular surface

Insertion:

-Base of the 5th metatarsal

Action:

-foot eversion

-assist in ankle plantar flexion

Fibularis tertius

Origin:

-Fibula : Distal third of the anterior surface of the fibula and interosseous membrane

-Anterior intermuscular septum

Insertion:

-Base of the 5th metatarsal (dorsal surface)

Action:

-Ankle dorsiflexion

-Assists in foot eversion

Innervation:

-Common peroneal nerve

Tibialis anterior

Origin:

-Tibia: lateral condyle and lateral surface of upper half of the tibia

-the interosseous membrane and crural fascia

Insertion:

-medial and plantar surface of medial coneiform

-base of the first metatarsal bone

Action:

-ankle dorsiflexion

Innervation:

-Common peroneal nerve

Extensor hallucis longus

Origin:

-Fibula: middle of the anterior surface

-interosseous membrane

Insertion:

-base of the distal phalanx of the great toe

Action:

-extension of the great toe

Innervation:

-Common peroneal nerve

Extensor digitorum longus

Origin:

-tibia

-fibula

-interosseous membrane

Insertion:

-toes 2-5 via dorsal digital expansions, into middle and distal phalanges

Action:

-extension of the lateral four digits

Innervation:

-Common peroneal nerve

Extensor digitorum brevis

Origin:

-Superolateral surface of calcaneus

Insertion:

-Extensor digitorum longus tendons of toes 2-4

Action:

-Toe extension (distal interphalangeal joints 2-4)

Innervation:

-Common peroneal nerve

Abductor digiti minimi

Action:

-abduction of the MP joint if the fifth (little) toe

-Flexion of the MP joint if the fifth (little) toe

Flexor digiti minimi

Action:

-flexion of the MP joint of the small toe

Abductor hallucis

Action:

-abduction of the large toe

Flexor digitorum brevis

Action:

-Flexion of the lateral four toes

Adductor hallucis

Action:

-adduction of the MP joint of the great toe

Flexor hallucis brevis

Action:

-flexion of the MP joint of the great toe

Quadratus plantae

Action:

-assist flexor digitorum longus in flexion of interphalangeal joints

lumbricals

Action:

-flexion of the MP joints

External oblique

Action:

-Horizontal spinal rotation -spine flexion

-lateral spinal flexion

-posterior pelvic tilt

Internal oblique

Action:

-horizontal spinal rotation

-spinal flexion

-lateral spinal flexion

-posterior pelvic tilt

Rectus abdominis

Action:

-spinal flexion

-posterior pelvic tilt

Transverse abdominis

Action:

-abdominal hollowing (sucking in belly button)

Quadratus lumborum

Action:

-spinal extension

-lateral spinal flexion

-lateral pelvic tilt

Iliocostalis

Action:

-spinal extension

Longissimus

Action:

-spinal extension

-lateral spinal flexion

-anterior pelvic tilt

Spinalis

Action:

-spinal extension

-lateral spinal flexion