Back & Lower Limb Muscles (action, origin, insertion, nerve)

gluteus maximus

extends hip

O: posterior ilium, sacrum, coccyx, sacrotuberous ligament, lumbodorsal fascia

I: gluteal tuberosity and IT band

N: inferior gluteal nerve

gluteus medius

abducts and medially rotates thigh

O: dorsal ilium

I: greater trochanter

N: superior gluteal nerve

gluteus minimus

abducts and medially rotates thigh

O: external surface of ilium

I: greater trochanter

N: superior gluteal nerve

Tensor Fascia Latae (TFL)

abducts hip, flexes hip

O: ASIS

I: IT band

N: superior gluteal nerve

piriformis

laterally rotates and abducts thigh

O: anterior surface of ilium (between S2 and S4)

I: greater trochanter

N: nerve to piriformis

obturator internus

laterally rotates thigh

O: pelvic surface of obturator membrane

I: greater trochanter

N: nerve to obturator internus

superior gemellus

laterally rotates thigh

O: ischial spine

I: greater trochanter

N: nerve to obturator internus

inferior gemellus

laterally rotates thigh

O: ischial tuberosity

I: greater trochanter

N: nerve to quadratus femoris

quadratus femoris

laterally rotates thigh

O: ischial tuberosity

I: quadrate tubercle of intertrochanteric crest

N: nerve to quad femoris

biceps femoris

extends thigh and flexes leg

O:

- long head: ischial tuberosity

- short head: linea aspera & lateral supracondylar line of femur

I: head of fibula

N:

- long head: tibial

- short head: common fibular

semitendinosus

extends thigh and flexes leg

O: ischial tuberosity

I: pes anserinus

N: tibial nerve

semimembranosus

Flexes leg at the knee and extends thigh at the hip

O: ischial tuberosity

I: medial tibial condyle

N: tibial nerve

fibularis longus

plantar flexes and everts foot

O: fibula head

I: plantar surface of medial cuneiform and base of 1st metatarsal bone

N: superficial fibular nerve

fibularis brevis

plantar flexes and everts foot

O: lateral fibula (lower 2/3)

I: tuberosity of 5th metatarsal

N: superficial fibular nerve

gastrocnemius

plantar flexes foot

O: medial and lateral condyle of femur

I: posterior calcaneus (achilles tendon)

N: tibial nerve

soleus

plantar flexes foot

O: posterior fibula and tibia

I: calcaneus (Achilles tendon)

N: tibial nerve

plantaris

plantar flexion

O: lateral supracondylar line of femur

I: calcaneus (Achilles tendon)

N: tibial nerve

popliteus

knee flexion

O: lateral femoral condyle and posterior horn of lateral meniscus

I: posterior surface of tibia

N: tibial nerve

flexor hallucis longus

flexes great toe

O: lower 2/3 of fibula

I: plantar surface of distal phalanx of great toe

N: tibial nerve

flexor digitorum longus

flexes toes

O: posterior surface of tibia

I: bases of distal phalanges of toes 2-5

N: tibial nerve

tibialis posterior

Plantar flexion and inversion of foot

O: tibia, fibula, and interosseous membrane

I: navicular, 2-4 metatarsals, cuneiforms

N: tibial nerve

trapezius

Elevates, depresses, retracts, and rotates the scapula; rotates the arm

O: external occipital protuberance, superior nuchal line, nuchal ligament, spinous processes of C7-T12

I: lateral 1/3 of clavicle, acromion, scapular spine

N: ventral rami of C3 and C4; accessory nerve

latissimus dorsi

Extends, adducts, and medially rotates the arm

O: thoracic vertebrae, lumbar fascia, iliac crest, lower ribs

I: intertubercular groove of humerus

N: thoracodorsal nerve (C6-C8)

levator scapulae

elevates scapula

O: transverse processes of C1-C4

I: superior medial border of scapula

N: dorsal scapular nerve and anterior rami of C3 and C4

rhomboid major

adducts scapula

O: spinous processes of T2-T5

I: medial border of scapula

N: dorsal scapular nerve

rhomboid minor

adducts scapula

O: spinous processes of C7-T1 and nuchal ligament

I: medial border of scapula at spine

N: dorsal scapular nerve

deltoid

abducts arm

O: lateral 1/3 of clavicle, acromion, spine of scapula

I: deltoid tuberosity of humerus

N: axillary nerve

supraspinatus

abducts arm

O: supraspinous fossa of scapula

I: greater tubercle

N: suprascapular nerve

infraspinatus

rotates arm laterally

O: infraspinous fossa of scapula

I: greater tubercle

N: suprascapular nerve

teres minor

rotates arm laterally

O: superior 2/3 lateral border of scapula

I: greater tubercle

N: axillary nerve

Subscapularis

medially rotates arm

O: subscapular fossa of scapula

I: lesser tubercle

N: upper & lower subscapular nerves

teres major

extends, adducts, and medially rotates arm

O: dorsal surface of inferior angle of scapula

I: intertubercular groove of humerus

N: lower subscapular nerve

splenius capitis

rotates head, bends head to one side, or extends neck

O: nuchal ligament and spinous processes of C7-T3/4

I: mastoid process and lateral superior nuchal line of occipital bone

N: posterior rami of C2-C3

splenius cervicis

extend neck/laterally flex and rotate head to same side

O: spinous process of T3-T6

I: posterior tubercles of transverse processes of C1-C3

N: lateral branches of posterior rami of lower cervical nerves

iliocostalis

extend and laterally flex the vertebral column

O: ribs and iliac crest

I: ribs and cervical transverse processes

N: dorsal rami of specific spinal nerves

Longissimus

extends vertebral column

O: transverse and spinous processes of vertebrae and iliac crest

I: mastoid process, transverse processes of cervical/thoracic/lumbar vertebrae, ribs

N: lateral branches of dorsal rami of spinal nerves

spinalis

extends vertebral column

O: nuchal ligament, spinous processes of cervical/thoracic/lumbar vertebrae

I: spinous processes of C2-T8

N: posterior rami of spinal nerves

semispinalis capitis

extends head, bends head to one side, or rotates head

O: transverse processes of C7-T6 and superior articular processes of C4-C7

I: occipital bone between superior/inferior nuchal lines

N: dorsal rami of cervical and upper thoracic spinal nerves

rectus capitis posterior major

head extension and ipsilateral rotation

O: bifid processes of C2

I: inferior nuchal line of occipital

N: suboccipital nerve (dorsal ramus of C1)

rectus capitis posterior minor

extends head and neck

O: posterior tubercle of atlas

I: medial part of inferior nuchal line of occipital bone

N: suboccipital nerve (dorsal ramus of C1)

Obliquus capitis superior

head extension, rotation, lateral flexion

O: transverse process of atlas

I: occipital bone between inferior/superior nuchal lines

N: suboccipital nerve (dorsal ramus of C1)

obliquus capitis inferior

rotate head and neck ipsilaterally

O: spinous process of C2

I: transverse process of C1

N: suboccipital nerve (dorsal ramus of C1)