1. MUSCLES OF THE ANKLE AND FOOT

2. Ankle and Foot Muscles Intrinsic vs. Extrinsic
Intrinsic Muscles
Fully contained in foot and toes
Both origin and insertion
Arranged in layers
Main function: support arches

3. Ankle and Foot Muscles Intrinsic vs. Extrinsic
We will focus on EXTRINSIC MUSCLES
Originate on lower leg (tibia/fibula) and insert on foot
Lower leg muscles are divided into 4 compartments
Anterior muscles cause dorsiflexion
Posterior muscles cause plantarflexion
Lateral muscles cause eversion
Medial muscles cause inversion

4. Posterior versus Anterior
Dorsi flexion
Plantar flexion

5. POSTERIOR MUSCLES
Plantar flexion muscles
Posterior muscles

6. Gastrocnemius Actions: plantarflexion of the ankle flexion of the knee
Posterior

7. Soleus Located beneath the gastrocnemius Action: plantarflexion
Posterior

8. Gastrocnemius
& Soleus

9. Achilles
Gastrocnemius and Soleus muscles form the achilles tendon, which attaches to the calcaneus
Largest tendon in body

10. Posterior Muscles (Calf)
 Gastrocnemius
Soleus
Achilles Tendon

11. Deep Posterior/Medial Muscles

12. Tibialis posterior
Location: Posterior to tibia and fibula underneath gastrocnemius and soleus
Note: Tendon passes posterior to medial malleolus.
Actions:
plantarflexion
Inversion
Posterior

13. Flexor Digitorum Longus
Location: Posterior to tibia underneath gastrocnemius/soleus
Note: Tendon passes posterior to medial malleolus.
Actions:
Toe flexion (2nd-5th toes)
Plantarflexion
Inversion
Maintains the longitudinal arch
Posterior

14. Flexor Hallucis Longus
Location: Posterior to the fibula, underneath gastrocnemius/soleus
Note: Tendon passes posterior to medial malleolus.
Actions:
Flexion of the great toe (1st Toe = Hallux)
Inversion
Plantarflexion
Posterior

15. Deep Posterior/Medial Muscles
Gastrocnemius/Soleus Cut
Tibialis Posterior
Flexor Hallucis Longus
Flexor Digitorum Longus
Calcaneus

16. Deep Posterior/Medial Muscles
Tibialis Posterior
Flexor Digitorum Longus
Flexor Hallucis Longus

17. Deep Posterior/Medial MusclesH= D= T=
Medial Malleolus
H= Flexor Hallucis Longus
T= Tibialis Posterior
D= Flexor Digitorum Longus

18. ANTERIOR MUSCLES
Dorsiflexion muscles
Anterior muscles

19. Tibialis anterior Location: Anterior to the tibia
Note: Tendon passes anterior to medial malleolus.
Actions:
Dorsiflexion
Inversion
*This tendon is usually prominent and visible during dorsiflexion
Anterior

20. Extensor digitorum longus
Location: Anterior lateral aspect of tibia/fibula
Note: Tendon passes anterior to lateral malleolus.
Actions:
Toe extension (2nd to 5th toes)
Dorsiflexion
Eversion
Anterior compartment
Anterior

21. Extensor hallucis longus
Location: anterior to tibia/fibula
Note: Tendon passes anterior in between tendons of tibialis anterior and extensor digitorum longus
Actions:
Extension of big toe
Dorsiflexion
Anterior

22. Anterior Muscles Tibialis Anterior Tibialis Anterior
 Tibialis Anterior
 Extensor Digitorum Longus
 Extensor Hallucis Longus
 Tibialis Anterior
 Extensor Digitorum Longus
 Extensor Hallucis Longus

23. Lateral muscles

24. Lateral Muscles Peroneal Muscles Group of 3 Muscles Peroneus Longus
Peroneus Brevis
Peroneus Tertius
Location: Lateral lower leg (Along fibula)
Note: Tendons of peroneus longus/brevis pass posterior to lateral malleolus
Action: Eversion
Anterior

25. Lateral Muscles Peroneus Longus Peroneus Brevis Lateral Malleolus
Peroneus Tertius