Lower Limb Muscles- Innervations And Actions

Front 1

Adductor Brevis/i

Back 1

Obturator nerve (L2, 3, 4)

Front 2

Adductor Brevis/a

Back 2

Adducts and flexes the thigh, and helps to laterally rotate the thigh

Front 3

Adductor Longus/i

Back 3

Obturator nerve (L2, 3, 4)

Front 4

Adductor Longus/a

Back 4

Adducts and flexes the thigh, and helps to laterally rotate the hip joint

Front 5

Adductor Magnus/i

Back 5

Obturator nerve (L2, 3, 4)

Tibial nerve innervates vertical/hamstring portion

Front 6

Adductor Magnus/a

Back 6

Powerful thigh adductor; superior horizontal fibers also help flex the thigh, while vertical fibers help extend the thigh

Front 7

Biceps Femoris- long head/i

Back 7

Tibial nerve (L5, S1, 2)

Front 8

Biceps Femoris- long head/a

Back 8

Flexes the knee, and also rotates the tibia laterally; long head also extends the hip joint

Front 9

Biceps Femoris- short head/i

Back 9

Common Peroneal nerve (L5, S1, 2)

Front 10

Biceps Femoris- short head/a

Back 10

Flexes the knee, and also rotates the tibia laterally; long head also extends the hip joint

Front 11

Extensor Digitorum Longus/i

Back 11

Deep Peroneal nerve (L4, 5, S1)

Front 12

Extensor Digitorum Longus/a

Back 12

Extend toes 2 - 5 and dorsiflexes ankle

Front 13

Extensor Hallucis Longus/i

Back 13

Deep Peroneal nerve (L4, 5, S1)

Front 14

Extensor Hallucis Longus/a

Back 14

Extends big toe and dorsiflexes ankle

Front 15

Flexor Digitorum Longus/i

Back 15

Tibial nerve (S2, 3)

Front 16

Flexor Digitorum Longus/a

Back 16

Flexes big toe, helps to supinate ankle, and is a very weak plantar flexor of ankle

Front 17

Gastrocnemius/i

Back 17

Tibial nerve (S1, 2)

Front 18

Gastrocnemius/a

Back 18

Powerful plantarflexor of ankle

Front 19

Gluteus Maximus/i

Back 19

Inferior Gluteal Nerve (L5, S1, 2)

Front 20

Gluteus Maximus/a

Back 20

Major extensor of hip joint, assists in laterally rotating the thigh; upper and middle third section of the muscle are abductors

Front 21

Gluteus Medius/i

Back 21

Superior Gluteal nerve (L4, 5, S1)

Front 22

Gluteus Medius/a

Back 22

Major abductor of thigh; anterior fibers help to rotate hip medially; posterior fibers help to rotate hip laterally

Front 23

Gluteus Minimus/i

Back 23

Superior Gluteal nerve (L4, 5, S1)

Front 24

Gluteus Minimus/a

Back 24

Abducts and medially rotates the hip joint

Front 25

Gracilis/i

Back 25

Obturator nerve (L2, 3)

Front 26

Gracilis/a

Back 26

Flexes the knee, adducts the thigh, and helps to medially rotate the tibia on the femur

Front 27

Iliacus/i

Back 27

Femoral (L1, 2, 3)

Front 28

Iliacus/a

Back 28

Flex the torso and thigh with respect to each other

Front 29

Inferior Gemellus/i

Back 29

Branches of the sacral plexus- L5 and S1

Front 30

Inferior Gemellus/a

Back 30

Rotates the thigh laterally

Front 31

Obturator Externus/i

Back 31

Posterior divison of Obturator nerve (L3, 4)

Front 32

Obturator Externus/a

Back 32

Rotates the thigh laterally; also helps adduct thigh

Front 33

Obturator Internus/i

Back 33

Branches of the sacral plexus- L5 and S1

Front 34

Obturator Internus/a

Back 34

Rotates the thigh laterally; also helps abduct the thigh when it is flexed

Front 35

Pectineus/i

Back 35

Femoral nerve (L2, 3, 4)

May also reveive some fibres from the obturator nerve

Front 36

Pectineus/a

Back 36

Adducts the thigh and flexes the hip joint

Front 37

Peroneus Brevis/i

Back 37

Superficial Peroneal nerve (L5, S1, 2)

Front 38

Peroneus Brevis/a

Back 38

Everts foot and plantarflexes ankle

Front 39

Peroneus Longus/i

Back 39

Superficial Peroneal nerve (L5, S1, 2)

Front 40

Peroneus Longus/a

Back 40

Everts foot and plantar flexes ankle; also helps to support the transverse arch of the foot

Front 41

Peroneus Tertius/i

Back 41

Deep Peroneal nerve (L5, S1)

Front 42

Peroneus Tertius/a

Back 42

Works with the extensor digitorum longus to dorsiflex, evert and abduct the foot

Front 43

Piriformis/i

Back 43

Piriformis nerve (L5, S1, 2)

Front 44

Piriformis/a

Back 44

Lateral rotator of the hip joint; also helps abduct the hip if it is flexed

Front 45

Plantaris/i

Back 45

Tibial nerve (L5, S1, 2)

Front 46

Plantaris/a

Back 46

Plantarflexor of ankle; flexor of knee

Front 47

Popliteus/i

Back 47

Tibial nerve (L4, 5, S1)

Front 48

Popliteus/a

Back 48

Rotates knee medially and flexes the leg on the thigh

Front 49

Psoas/i

Back 49

Direct fibres of Lumbar plexus (L1, 2, 3)

Front 50

Psoas/a

Back 50

Flex the torso and thigh with respect to each other

Front 51

Quadratus Femoris/i

Back 51

Fibres from L5 and S1

Front 52

Quadratus Femoris/a

Back 52

Rotates the hip laterally; also helps adduct the hip

Front 53

Rectus Femoris/i

Back 53

Femoral nerve (L2, 3, 4)

Front 54

Rectus Femoris/a

Back 54

Extends the knees

Front 55

Sartorius/i

Back 55

Femoral nerve (L2, 3, 4)

Front 56

Sartorius/a

Back 56

Flexes and laterally rotates the hip joint and flexes the knee

Front 57

Semimembranosus/i

Back 57

Tibial nerve (L5, S1, 2)

Front 58

Semimembranosus/a

Back 58

Extends the thigh, flexes the knee, and also rotates the tibia medially, especially when the knee is flexed

Front 59

Semitendinosus/i

Back 59

Tibial nerve (L5, S1, 2)

Front 60

Semitendinosus/a

Back 60

Extends the thigh and flexes the knee, and also rotates the tibia medially, especially when the knee is flexed

Front 61

Soleus/i

Back 61

Powerful plantarflexor of ankle

Front 62

Soleus/a

Back 62

Tibial nerve (S1, 2)

Front 63

Superior Gemellus/i

Back 63

Branches of the Lumbar plexus: L5, S1)

Front 64

Superior Gemellus/a

Back 64

Rotates the thigh laterally; also helps abduct the flexed thigh

Front 65

Tensor Fascia Lata/i

Back 65

Superior Gluteal nerve (L4, 5, S1)

Front 66

Tensor Fascia Lata/a

Back 66

Helps stabilize and steady the hip and knee joints by putting tension on the iliotibial band of fascia

Front 67

Tibialis Anterior/i

Back 67

Deep Peroneal nerve (L4, 5, S1)

Front 68

Tibialis Anterior/a

Back 68

Dorsiflexor of ankle and invertor of foot

Front 69

Tibialis Posterior/i

Back 69

Tibial nerve (L4, 5)

Front 70

Tibialis Posterior/a

Back 70

Principal invertor of foot; also adducts foot, plantar flexes ankle, and helps to supinate the foot

Front 71

Vastus Intermedius/i

Back 71

Femoral nerve (L2, 3, 4)

Front 72

Vastus Intermedius/a

Back 72

Extends the knee

Front 73

Vastus Lateralis/i

Back 73

Femoral nerve (L2, 3, 4)

Front 74

Vastus Lateralis/a

Back 74

Extends the knee

Front 75

Vastus Medialis/i

Back 75

Femoral nerve (L2, 3, 4)

Front 76

Vastus Medialis/a

Back 76

Extends the knee