THE MUSCLES OF THE FOOT. 



66 1 



Variations.— The flexor brevis hallucis is frequently intimately fused with the abductor 



hallucis. 



A portion of the deeper fibres of the flexor brevis hallucis is frequently inserted into the 

 whole length of the first metatarsal. Occasionally these fibres are quite distinct from the rest 

 of the muscle, forming what has been termed an opponens hallucis. 



In the description of the muscle given above, account has been taken only of what is usually 

 described as the inner portion, the flexor brevis pollicis being usually regarded as consisting 

 of two bellies, the second of which is inserted into the lateral side of the base of the first 

 phalanx of the great toe. The relations of this outer belly and its nerve-supply, however, indi- 

 cate that it belongs to an entirely different layer than the medial belly. It will, therefore, be 

 considered later in connection with the interossei (page 663). 



Fig. 62S. 



Os calcis, inner tubercle-^ 



Abductor hallucis, 

 calcaneal origin 

 Internal annular ligament 



Flexor brevis digitorum, origin' 

 Flexor longus hallucis tendon 



Tibialis posticus tendon ^ 



Flexor longus digitorum tendon 



Abductor hallucis, part of origin 



Abductor hallucis, cut 



First plantar interosseus 

 Flexor brevis hallucis 



Lumbricales 



Flexor longus hallucis tendon 



Flexor brevis digitorum 

 Flexor longus digitorum 



Os calcis, outer tubercle 



Abductor minimi digiti, origin 

 Long plantar ligament 



Peroneus longus tendon 



Abductor minimi digiti, occasional 

 nsertion (Abductor ossis metatarsi 

 quinti) 



Flexor accessorius 

 Tubercle of fifth metatarsus 

 Plexor brevis minimi digiti, 

 part of its origin 



-Flexor longus digitorum 



Flexor brevis tjiinimi digiti 



Abductor minimi digiti, 

 insertion 



Flexor longus digitorum 

 tendons 



Flexor brevis digitorum 

 tendons, cut 



Long and accessory flexors of right sole, exposed by removal of superficial muscles. 



3. Abductor Hallucis (Fig. 627). 



Attachments. — The abductor hallucis extends along the inner border of the 

 foot, arising from the inner tubercle and surface of the calcaneum and from the 

 plantar aponeurosis and being inserted, along with the flexor brevis hallucis, into the 

 inner side of the base of the first phalanx of the great toe. 



Nerve-Supply. — By the internal plantar nerve from the fourth and fifth lumbar 

 and first sacral nerves. 



Action. — To abduct and flex the hallux. 



