Lower Limb Muscles Part 2

Question 1

Tibialis Anterior

Answer 1

1. Origin: proximal lateral surface of tibia
2. Insertion: Plantar aspect of 1st metatarsal and medial cuneiform
3. Actions: Dorsiflexion of foot @ ankle joint and inversion of foot @ subtalar j
4. Nerve: deep fibular (peroneal)

Question 2

Extensor Hallucis Longus

Answer 2

1. Origin: middle portion of anterior surface of fibula
2. Insertion: Dorsal aspect of distal phalanx of big toe
3. Actions: Extension of big toe @ MTP & IP joints, dorsiflexion of foot @ ankle joint and inversion of foot @ subtalar joint
4. Nerve: Deep fibular (peroneal)

Question 3

Extensor Digitorum Longus

Answer 3

1. Origin: most of anterior surface of fibula and lateral condyle of tibia
2. Insertion: middle and distal phalanx of toes 2-5
3. Actions: extension of toes 2-5 @ MTP & IP joints, eversion of foot @ subtalar joint and dorsiflexion of foot @ ankle joint
4. Nerve: Deep fibular (peroneal)

Question 4

Fibular (peroneus) Tertius

Answer 4

1. Origin: Distal 1/3 of anterior surface of fibula & interosseous
2. Insertion: Base of 5th metatarsal (anterior to tuberosity)
3. Actions: eversion of foot @ subtalar joint and dorsiflexion of foot @ ankle joint
4. Deep fibular (peroneal)

Question 5

Fibularis (peroneus) Longus

Answer 5

1. Origin: Head of fibula and proximal 1/2 of lateral surface of fibula
2. Insertion: Plantar aspect of base of 1st metatarsal and medial cuneiform
3. Actions: plantar flexion of foot @ ankle joint and eversion of foot @ subtalar joint
4. Nerve: superficial fibular (peroneal)

Question 6

Fibularis (peroneus) Brevis

Answer 6

1. Origin: Distal 1/2 of lateral surface of fibula
2. Insertion: Base of 5th metatarsal
3. Actions: eversion of foot @ subtalar joint and plantar flexion of foot @ ankle joint
4. Nerve: Superficial fibular (peroneal)

Question 7

Extensor Digitorum Brevis

Answer 7

1. Origin: dorsal surface of calcaneus
2. Insertion: lateral side of tendon of EDL for toes 2-5
3. Actions: extension of toes 2-5
4. Nerve: Deep fibular (peroneal)

Question 8

Extensor Hallucis Brevis

Answer 8

1. Origin: dorsal surface of calcaneus
2. Insertion: proximal plasma phalanx of big toe
3. Actions: extension of big toe @ MTP joint
4. Nerve: deep fibular (peroneal)

Question 9

Gastrocnemius

Answer 9

1. Origin: medial and lateral condyles of femur
2. Insertion: calcaneus via calcaneal (Achilles) tendon
3. Actions: plantar flexion of foot @ ankle joint and flexion of leg @ knee joint
4. Nerve: Tibial

Question 10

Soleus

Answer 10

1. Origin: head and proximal 1/3 of fibula and soleal line of tibia
2. Insertion: calcaneus via calcaneal (Achilles) tendon
3. Action: plantar flexion of foot @ ankle joint
4. Nerve: tibial

Question 11

Plantaris

Answer 11

1. Origin: lateral supracondylar ridge of femur
2. Insertion: calcaneus via calcaneal (Achilles) tendon
3. Actions: plantar flexion of foot @ ankle joint and flexion of leg @ knee joint
4. Nerve: tibial

Question 12

Flexor Hallucis Longus

Answer 12

1. Origin: distal posterior surface of fibula
2. Insertion: distal phalanx of big toe
3. Actions: Flexion of leg @ knee joint, plantar flexion of foot @ ankle joint and inversion of foot @ subtalar joint
4. Nerve: tibial

Question 13

Flexor Digitorum Longus

Answer 13

1. Origin: middle posterior surface of tibia
2. Insertion: distal phalanx of toes 2-5
3. Actions: flexion of toes 2-4 @ MTP and IP joints, plantar flexion of foot @ ankle joint and inversion of foot @ subtalar joint
4. Nerve: tibial

Question 14

Tibialis Posterior

Answer 14

1. Origin: Proximal posterior aspect of tibia and fibula
2. Insertion: calcaneus, navicular tuberosity, cuboid and metatarsals 2-4
3. Actions: Plantar flexion of foot @ ankle joint and inversion of foot @ subtalar joint
4. Nerve: tibial