Distal Lower Limb

Question 1

Tibialis anterior origin, insertion, action and innervation

Answer 1

∙Origin – Lateral tibia & Medial fibula
∙Insertion – Inferior aspect of medial cuneiform
∙Action – Ankle dorsiflexion
Foot inversion

∙Innervation - deep fibular nerve

Question 2

Extensor hallucis longus origin, insertion, action and innervation

Answer 2

∙Origin – Medial fibula
∙Insertion – Base of distal phalynx I
∙Action – Hallux extension
Ankle dorsiflexion

∙Innervation - deep fibular nerve

Question 3

Extensor dgitorum longus origin, insertion, action and innervation

Answer 3

∙Origin – Lateral tibia & Medial fibula
∙Insertion – Bases of distal and middle phalanges II – V
∙Action – Toe extension
Ankle dorsiflexion

∙Innervation - deep fibular nerve

Question 4

Fibularis tertius origin, insertion, action and innervation

Answer 4

∙Origin – Medial fibula
∙Insertion – Medial aspect of metatarsal V
∙Action – Ankle dorsiflexion
Foot eversion

∙Innervation - deep fibular nerve

Question 5

Fibularis longus origin, insertion and action

Answer 5

∙Origin – Lateral fibula
∙Insertion – Inferolateral aspect of medial cuneiform
Base of metatarsal I
∙Action – Ankle plantarflexion
Foot eversion

∙Innervation - superficial fibular nerve

Question 6

Fibularis brevis origin, insertion, action and innervation

Answer 6

∙Origin – Lateral fibula
∙Insertion – Base of metatarsal V
∙Action – Foot eversion
∙Innervation - Superficial fibular nerve

Question 7

Gastrocnemius attachments, action and innervation

Answer 7

Attachments: The lateral head originates from the lateral femoral condyle. The medial head originates from the medial femoral condyle.
The two heads combine to form a single muscle belly.
Distally, the muscle belly converges with the soleus muscle to form the calcaneal tendon. This inserts onto the calcaneus.

Actions: Plantarflexion at the ankle joint and flexion at the knee joint.

Innervation: Tibial nerve.

Question 8

Soleus attachments, actions and innervation

Answer 8

Attachments: Originates from the soleal line of the tibia and proximal fibula. The muscle converges with the fibres of the gastrocnemius to form the calcaneal tendon, which inserts onto the calcaneus.

Actions: Plantarflexion of the foot at the ankle joint.

Innervation: Tibial nerve

Question 9

Plantaris attachments, actions and innervation

Answer 9

Attachments: Originates from the lateral supracondylar line of the femur. The fibres condense into a tendon which travels down the leg, between the gastrocnemius and soleus muscles. It blends with the calcaneal tendon and inserts onto the calcaneus.

Actions: Contributes to plantarflexion at the ankle joint and flexion at the knee joint.

Innervation: Tibial nerve.

Question 10

Popliteus attachments, actions and innervation

Answer 10

Attachments: Originates from the lateral condyle of the femur and the lateral meniscus of the knee joint. It inserts onto the proximal tibia, immediately above the origin of the soleus muscle.

Actions: Lateral rotation of the femur relative to the tibia. This ‘unlocks’ the knee joint so that flexion can occur.

Innervation: Tibial nerve

Question 11

Flexor digitorum longus attachments, actions and innervation

Answer 11

Attachments: Originates from the medial surface of the tibia and attaches to the plantar surfaces of the lateral four digits.

Actions: Flexion of the lateral four toes.

Innervation: Tibial nerve

Question 12

Flexor hallucis longus attachments, actions and innervation

Answer 12

Attachments: Originates from the posterior surface of the fibula and attaches to the plantar surface of the phalanx of the great toe.

Actions: Flexion of the great toe.

Innervation: Tibial nerve

Question 13

Tibialis posterior attachments, actions and innervation

Answer 13

Attachments: Originates from the posterior surface and interosseous membrane of the tibia and fibula. The tendon enters the foot posterior to the medial malleolus and attaches to the plantar surfaces of the medial tarsal bones.

Actions: Inversion and plantarflexion of the foot. It also contributes to the medial arch of the foot.

Innervation: Tibial nerve

Question 14

Boundaries and contents of the popliteal fossa

Answer 14

Boundaries-
• Superomedial border – semimembranosus.
• Superolateral border – biceps femoris.
• Inferomedial border – medial head of the gastrocnemius.
• Inferolateral border – lateral head of the gastrocnemius and plantaris

Contents-
• Popliteal artery
• Popliteal vein
• Tibial nerve
• Common fibular nerve (common peroneal nerve)

Question 15

Pulse points

Answer 15

Medial malleolus
1st metatarsal space