Synergists and Force Couples

Question 1

ankle dorsiflexion

Answer 1

4 muscles:

• tibialis anterior
• extensor hallucis longus
• extensor digitorum longus
• peroneus tertius

Question 2

ankle plantar flexion

Answer 2

8 muscles:

• gastrocnemius
• soleus
• peroneus longus
• peroneus brevis
• plantaris
• tibialis posterior
• flexor digitorum longus
• flexor hallucis longus

Question 3

ankle inversion

Answer 3

5 muscles:

• tibialis anterior
• tibialis posterior
• extensor hallucis longus
• flexor digitorum longus
• flexor hallucis longus

Question 4

ankle eversion

Answer 4

4 muscles:

• extensor digitorum longus
• peroneus tertius
• peroneus longus
• peroneus brevis

Question 5

hallux extension

Answer 5

• extensor hallucis longus (at MTP and IP)

Question 6

extension of digits 2-5 at MTP, PIP, and DIP

Answer 6

• extensor digitorum longus

Question 7

hallux flexion

Answer 7

• flexor hallucis longus (MTP and IP)
• flexor hallucis brevis (MTP only)

Question 8

flexion of digits 2-5

Answer 8

• flexor digitorum longus (at MTP, PIP, and DIP)
• flexor digitorum brevis (at MPT and PIP only)