432 



THE MUSCULAK SYSTEM. 



The Muscles in the Sole of the Foot. 



The muscles in the sole of the foot are divisible into four layers placed deep to 

 the plantar aponeurosis. 



The first layer includes the abductor hallucis, flexor digitorum brevis, and 

 abductor digiti quinti. The second layer consists of the lumbricales and quadratus 

 plantse, together with the tendons of the flexor hallucis longus and flexor digitorum 

 longus. The third layer comprises the flexor hallucis brevis, adductor hallucis, and 



Abductor digiti quinti 

 (origin) 



Quadratus plantse (origin} 



Long plantar ligament 



Plantar calcaneo-cuboid 

 ligament' 



Tibialis posterior (part of 

 insertion 



Peronaeus brevis 

 (insertion) 



Flexor digiti quinti 

 brevis (origin) 



Adductor hall'.icis 



(origin of oblique 



head) 



Flexor digitorum brevis (origin) 

 Abductor hallucis (origin) 



Attachments of 

 plantar calcaneo- 

 navicular ligament 



Flexor hallucis brevis 

 (origin) 



Tibialis posterior 

 v main partof insertion) 



Peronseus longus 

 (insertion) 



Tibialis anterior 

 insertion) 



FIG. 386. MUSCLE- ATTACHMENTS TO LEFT TARSUS AND METATARSUS (Plantar Aspect). 



flexor digiti quinti brevis. The fourth layer consists of the interossei (plantar and 

 dorsal), placed between the metatarsal bones : and the tendons of insertion of the 

 tibialis posterior and peronseus longus. 



FIRST LAYER. 



M. Abductor Hallucis. The abductor hallucis has a double origin: (1) by a 

 short tendon from the medial side of the medial process of the tuberosity of the 

 calcaneus (Fig. 386), and (2) by fleshy fibres from the ligamentum laciniatum, 

 the plantar aponeurosis which covers it, and the intermuscular septum between it 

 and the flexor digitorum brevis. 



The muscle lies superficially, along the medial border of the sole ; its tendon is 



