Muscles Of The Lower Extremity

Front 1

Iliacus
(iliopsoas)

Back 1

Ori: Iliac fossa
Ins: Lesser trochanter
Inn: Femoral
Act: Flexor, medial rotator of thigh (with psoas)

Front 2

Sartorius

Back 2

Ori: ASIS
Ins: Upper medial tibia
Inn: Femoral
Act: Flexor, lateral rotator of thigh, medial rotator of leg

Front 3

Rectus femoris

Back 3

Ori: AIIS
Ins: Base of patella, tibial tuberosity
Inn: Femoral
Act: Flexor of thigh, extensor of leg

Front 4

Vastus medialis

Back 4

Ori: Intertrochanteric line, linea aspera
Ins: Medial patella, tibial tuberosity
Inn: Femoral
Act: Extensor of leg

Front 5

Vastus intermedius

Back 5

Ori: Upper shaft of femur
Ins: Upper patella, tibial tuberosity
Inn: Femoral
Act: Extensor of leg

Front 6

Vastus lateralis

Back 6

Ori: Intertrochanteric line, greater trochanter, linea aspera, gluteal tuberosity
Ins: Lateral patella, tibial tuberosity
Inn: Femoral
Act: Extensor of leg

Front 7

Adductor longus

Back 7

Ori: Body of pubis
Ins: Linea aspera
Inn: Obturator
Act: Adductor of thigh, flexor of thigh

Front 8

Adductor brevis

Back 8

Ori: Body of pubis, inferior pubic ramus
Ins: Pectineal line, linea aspera
Inn: Obturator
Act: Adductor of thigh, flexor of thigh

Front 9

Adductor magnus (adductor part)

Back 9

Ori: Ischiopubic ramus
Ins: Linea aspera, medial supracondylar line
Inn: Obturator
Act: Adductor of thigh

Front 10

Adductor magnus (hamstring part)

Back 10

Ori: Ischial tuberosity
Ins: Adductor tubercle, supracondylar line
Inn: Sciatic
Act: Extensor of thigh

Front 11

Pectineus

Back 11

Ori: Pectineal line of pubis
Ins: Pectineal line of femur
Inn: Obturator, femoral
Act: Adductor of thigh, flexor of thigh

Front 12

Gracilis

Back 12

Ori: Body of pubis, inferior pubic ramus
Ins: Medial upper tibia
Inn: Obturator
Act: Adductor of thigh, flexor of thigh, flexor of leg, medial rotator of leg

Front 13

Obturator externus

Back 13

Ori: Obturator foramen/membrane
Ins: Intertrochanteric fossa
Inn: Obturator
Act: Lateral rotator of thigh

Front 14

Gluteus maximus

Back 14

Ori: Ilium, sacrum, coccyx, sacrotuberous ligament
Ins: Gluteal tuberosity, IT tract
Inn: Inferior gluteal
Act: Extensor of thigh, lateral rotator of thigh

Front 15

Gluteus medius

Back 15

Ori: Superior ilium
Ins: Greater trochanter
Inn: Superior gluteal
Act: Abductor of thigh, medial rotator of thigh

Front 16

Gluteus minimus

Back 16

Ori: Ilium between ant. and inf. gluteal lines
Ins: Greater trochanter
Inn: Superior gluteal
Act: Abductor of thigh, medial rotator of thigh

Front 17

Tensor fasciae latae

Back 17

Ori: Iliac crest, ASIS
Ins: IT tract
Inn: Superior gluteal
Act: Flexor of thigh, abductor of thigh, medial rotator of thigh

Front 18

Piriformis

Back 18

Ori: Pelvic sacrum, sacrotuberous ligament
Ins: Greater trochanter
Inn: S1, S2
Act: Lateral rotator of thigh

Front 19

Obturator internus

Back 19

Ori: Ischiopubic rami
Ins: Greater trochanter
Inn: Nerve to obturator internus
Act: Abductor of thigh, lateral rotator of thigh

Front 20

Superior gemellus

Back 20

Ori: Ischial spine
Ins: Obturator internus tendon
Inn: Nerve to obturator internus
Act: Lateral rotator of thigh

Front 21

Inferior gemellus

Back 21

Ori: Ischial tuberosity
Ins: Obturator internus tendon
Inn: Nerve to quadratus femoris
Act: Lateral rotator of thigh

Front 22

Quadratus femoris

Back 22

Ori: Ischial tuberosity
Ins: Intertrochanteric crest
Inn: Nerve to quadratus femoris
Act: Lateral rotator of thigh

Front 23

Semitendinosus

Back 23

Ori: Ischial tuberosity
Ins: Upper tibia
Inn: Tibial
Act: Extensor of thigh, flexor of leg, medial rotator of leg

Front 24

Semimembranosus

Back 24

Ori: Ischial tuberosity
Ins: Medial condyle of tibia
Inn: Tibial
Act: Extensor of thigh, flexor of leg, medial rotator of leg

Front 25

Biceps femoris (long head; short head)

Back 25

Ori: Ischial tuberosity; linea aspera
Ins: Head of fibula
Inn: Tibial; common fibular
Act: Extensor of thigh, flexor of leg, lateral rotator of leg

Front 26

Tibialis anterior

Back 26

Ori: Lateral condyle of tibia
Ins: First cuneiform, first metatarsal
Inn: Deep fibular
Act: Dorsiflexor, inverter of foot

Front 27

Extensor hallucis longus

Back 27

Ori: Anterior fibula
Ins: Distal phalanx of big toe
Inn: Deep fibular
Act: Extensor of the first digit, dorsiflexor, inverter of foot

Front 28

Extensor digitorum longus

Back 28

Ori: Lateral condyle of tibia, upper fibula
Ins: Middle and distal phalanges
Inn: Deep fibular
Act: Extensor of toes, dorsiflexor of foot

Front 29

Fibularis tertius

Back 29

Ori: Distal fibula
Ins: 5th metatarsal
Inn: Deep fibular
Act: Dorsiflexor, everter of foot

Front 30

Fibularis longus

Back 30

Ori: Lateral condyle of tibia, head of fibula
Ins: 1st metatarsal, medial cuneiform
Inn: Superficial fibular
Act: Plantar flexor, everter of foot

Front 31

Fibularis brevis

Back 31

Ori: Lower lateral fibula
Ins: 5th metatarsal
Inn: Superficial fibular
Act: Plantar flexor, everter of foot

Front 32

Gastrocnemius

Back 32

Ori: Femoral condyles
Ins: Tendo calcaneus
Inn: Tibial
Act: Flexor of leg, plantar flexor of foot

Front 33

Soleus

Back 33

Ori: Head of fibula, soleal line of tibia
Ins: Tendo calcaneus
Inn: Tibial
Act: Plantar flexor of foot

Front 34

Plantaris

Back 34

Ori: Lower lateral supracondylar line
Ins: Tendo calcaneus
Inn: Tibial
Act: Flexor of leg, medial rotator of leg

Front 35

Popliteus

Back 35

Ori: Lateral femoral condyle
Ins: Upper posterior tibia
Inn: Tibial
Act: Flexor of leg, medial rotator of leg

Front 36

Flexor hallucis longus

Back 36

Ori: Lower fibula
Ins: Distal phalanx of big toe
Inn: Tibial
Act: Flexor of distal phalanx of big toe

Front 37

Flexor digitorum longus

Back 37

Ori: Middle posterior tibia
Ins: Distal phalanges of lateral 4 toes
Inn: Tibial
Act: Flexor of lateral 4 toes, plantar flexor of foot

Front 38

Tibialis posterior

Back 38

Ori: Upper tibia and fibula
Ins: Tuberosity of navicular, medial cuneiform
Inn: Tibial
Act: Plantar flexor of foot, inverter of foot

Front 39

Extensor digitorum brevis

Back 39

Ori: Dorsal calcaneus
Ins: Tendons of extensor digitorum longus
Inn: Deep fibular
Act: Extensor of toes

Front 40

Extensor hallucis brevis

Back 40

Ori: Dorsal calcaneus
Ins: Proximal phalanx of big toe
Inn: Deep fibular
Act: Extensor of big toe

Front 41

Abductor hallucis

Back 41

Ori: Medial tubercle of calcaneus
Ins: Proximal phalanx of big toe
Inn: Medial plantar
Act: Abductor of big toe

Front 42

Flexor digitorum brevis

Back 42

Ori: Medial tubercle of calcaneus
Ins: Middle phalanges of lateral 4 toes
Inn: Medial plantar
Act: Flexor of middle phalanges of lateral 4 toes

Front 43

Abductor digiti minimi

Back 43

Ori: Medial and lateral tubercles of calcaneus
Ins: Proximal phalanx of 5th toe
Inn: Lateral plantar
Act: Abducts 5th toe

Front 44

Quadratus plantae

Back 44

Ori: Medial and lateral calcaneus
Ins: Tendons of flexor digitorum longus
Inn: Lateral plantar
Act: Flexor of toes

Front 45

Lumbricals

Back 45

Ori: Tendons of flexor digitorum longus
Ins: Proximal phalanges
Inn: 1st by medial plantar, rest by lateral plantar
Act: Flexors of metatarsophalangeal joints and extensors of interphalangeal joints

Front 46

Flexor hallucis brevis

Back 46

Ori: Cuboid, lateral cuneiform
Ins: Proximal phalanx of big toe
Inn: Medial plantar
Act: Flexor of the big toe

Front 47

Adductor hallucis

Back 47

Ori: Oblique - metarsals 2-4, transverse - lateral 4 metatarsophalangeal joints
Ins: Proximal phalanx of big toe
Inn: Lateral plantar
Act: Adductor of big toe

Front 48

Flexor digiti minimi brevis

Back 48

Ori: 5th metatarsal
Ins: Proximal phalanx of 5th toe
Inn: Lateral plantar
Act: Flexor of 5th toe

Front 49

Plantar interossei

Back 49

Ori: Medial sides of metatarsals 3-5
Ins: Medial sides of proximal phalanges 3-5
Inn: Lateral plantar
Act: Adductor of toes, resist extension of metatarsophalangeal joints and flexion of interphalangeal joints

Front 50

Dorsal interossei

Back 50

Ori: Adjacent metatarsals
Ins: Proximal phalanges of 2nd toes (med/lat sides), and 3rd and 4th toes (lat sides)
Inn: Lateral plantar
Act: Abductor of toes, flexor of proximal phalanges, extensor of distal phalanges

Front 51

Damage to the femoral nerve

Back 51

Impaired flexion of the hip (pectineus, iliacus), impaired extension of the leg (anterior compartment of thigh)

Front 52

Damage to the obturator nerve

Back 52

Weakness in adduction (adductor muscles).

Results in lateral swinging of limb during walking

Front 53

Damage to the sciatic nerve

Back 53

Impaired extension of the thigh, impaired flexion of the leg (posterior compartment muscles), loss of dorsiflexion and eversion of the foot (all leg and foot muscles).

Requires increased hip flexion during walking to lift dropped foot off the ground.

Front 54

Damage to the tibial nerve

Back 54

Loss of plantar flexion of the foot (all leg and foot muscles), impaired inversion (tibialis posterior)

Results in difficulty in getting the heel off the ground and shuffling gait results.

Characteristic clawing of the toes.

Front 55

Damage to the common fibular nerve

Back 55

Results in foot drop (paralysis of dorsiflexors and evertors of the foot), loss of sensation on the dorsum of the foot and lateral aspect of the leg.

Front 56

Damage to the deep fibular nerve

Back 56

Results in foot drop.

Characteristic high-stepping gait.

Front 57

Damage to the superficial fibular nerve

Back 57

Loss of eversion of the foot.

Front 58

Flexors of the hip

Back 58

Iliopsoas, tensor fasciae latae, rectus femoris, adductors, sartorius, pectineus

"PASTRI"

Front 59

Extensors of the hip

Back 59

Hamstrings (posterior compartment muscles of thigh), gluteus maximus, adductor magnus

Front 60

Adductors of the hip

Back 60

Adductors, pectineus, gracilis

"Great major league baseball players"
Gracilis, magnus, longus, brevis, pectineus

Front 61

Abductors of the hip

Back 61

Gluteus medius, gluteus minimus, tensor fasciae latae

Front 62

Medial rotators of the hip

Back 62

Tensor fasciae latae, gluteus medius, gluteus minimus

Front 63

Lateral rotators of the hip

Back 63

P, G, O, G, O, Q, gluteus maximus

"Pretty girls often get obnoxious questions"

Front 64

Flexion of the knee

Back 64

Hamstrings, gracilis, sartorius, gastrocnemius, popliteus

Front 65

Extension of the knee

Back 65

Quadriceps femoris

Front 66

Medial rotators of the knee

Back 66

Semitendinosus, popliteus

Front 67

Lateral rotators of the knee

Back 67

Biceps femoris

Front 68

Dorsiflexors of the ankle

Back 68

Tibialis anterior, extensor digitorum longus, extensor hallucis longus, fibularis tertius

"FEET" going from Fibula to Tibia, Fibularis tertius, Extensor digitorum longus, Extensor hallucis longus, Tibialis anterior

Front 69

Plantar flexion of the ankle

Back 69

Triceps surae, plantaris, tibialis posterior, fibularis longus, flexor digitorum longus, flexor hallucis longus (when the knee is fully flexed)

"Try Plantar Flexing From Flexed Toes"

Front 70

Inversion at the intertarsal joint

Back 70

Tibialis posterior, tibialis anterior, triceps surae

Front 71

Eversion at the intertarsal joint

Back 71

Fibularis longus, fibularis brevis, fibularis tertius

Front 72

Flexion at the metatarsophalangeal joint

Back 72

Lumbricals, interossei, flexor hallucis brevis, flexor digiti minimi brevis

Front 73

Extension at the metatarsophalangeal joint

Back 73

Extensor digitorum longus, extensor digitorum brevis, extensor hallucis longus

Front 74

Flexion at the interphalangeal joint

Back 74

Flexor digitorum longus, flexor digitorum brevis, flexor hallucis longus

Front 75

Extension at the interphalangeal joint

Back 75

Extensor digitorum longus, extensor digitorum brevis, extensor hallucis longus

Front 76

The pes anserinus

Back 76

Located on the anteromedial proximal tibia.

From medial to lateral insertions:
SGT ("sergeant") FOT ("fought")
Sartorius, Gracilis, semiTendinosus
Femoral, Obturator, Tibial

Front 77

Lesser gluteal paralysis

Back 77

Trendelenburg gait:

Contralateral pelvis drop, lateral flexion of trunk toward ipsilateral side

Front 78

Gluteus maximus paralysis

Back 78

Slight lean back at heel strike

Front 79

Vasti paralysis

Back 79

Allow forward momentum of swinging leg to carry its knee into complete extension just before heel strike, lean slightly forward during first half of support phase

Front 80

Hamstrings paralysis

Back 80

Backward lean at heel strike

Front 81

Iliopsoas and adductor paralysis

Back 81

Swing phase flexion of hip accompanied by some abduction (due to tensor fasciae latae and lesser gluteals)

Front 82

Rectus femoris paralysis

Back 82

Rely on iliopsoas (ok)

Front 83

Triceps surae paralysis

Back 83

Short steps, lean back to keep weight on heels, or walk with toes out to use fibularis longus and brevis

Front 84

Anterior tibial muscles paralysis

Back 84

High stepping, foot slapping gait

Front 85

Spinal stenosis

Back 85

-Bilateral
-Rest relieves it
-Pseudo-claudications (true claudications relieved by rest even while standing)

Front 86

S1 Radiculopathy

Back 86

Cause: L5/S1 herniation
Symptoms: posterior leg, lateral foot pain, numbness in S1 dermatome, loss of ankle reflex, weak plantar flexion

Front 87

L5 Radiculopathy

Back 87

Cause: L4/L5 herniation
Symptoms: pain down leg, dorsum of foot, numbness in great toe, drop foot or weakness in EHL

Front 88

L4 Radiculopathy

Back 88

Cause: not given, L3/L4 herniation?
Symptoms: pain to knee and mesial leg, numbness in anterior thigh, loss of knee reflex, weakness in quads

Front 89

Cauda equina syndrome
(remember the 4 B's)

Back 89

Bilateral leg pain
Bilateral weakness, numbness
Bilateral loss of reflex
Bowel, bladder loss of function

Front 90

Myelopathy

Back 90

-Bilateral leg weakness
-Increased tone, reflexes
-Sensory level (loss?)
-Babinski reflex (dorsiflexion of hallux)
-Bowel, bladder function loss