162 ANATOMY IN A NUTSHELL. 



Origin. — (Plate L1II.) — Inner or larger head from inner concave surface 

 of os calcis below groove for tendon of Flexor longus hallucis. Outer head from 

 outer surface of OS calcis and long plantar ligament. 



[nsertion. (Plate LIX.) — Outer margin, upper and under surfaces of 

 tendon of Flexor Longus digitorum. 



A< pion. Assists long flexors of toes. 



Nerve Supply. — External plantar. 



Bl Si ppli . External plantar. 



Lumbricales.— Description. — (Plate LIX.) — These are accessory to ten- 

 dons of the Flexor Longus digitorum. 



Origin. -(Plate LIX.) — Tendons of long flexors. 



Insertion. — (Plate LIX.) — Expansion of long extensors and base of first 

 phalanx of corresponding toe. 



A< riON. Accessory to flexors and extensors. 



\i i;\ i. Supply. — Two inner muscles get the internal plantar. Two outer 

 muscles gel the external plantar. 



Note. — The first inner lumbricalis has internal plantar and the three outer 

 have external plantar in one out of ten cases. 



Blood Supply. — Plantar arteries. 



Flexor brevis hallucis. — Description. — (Plate LX.) — This muscle has one 

 origin and two insertions, and is situated along the inner and under surfaces of 

 the metatarsal of the great toe. The inner tendon joins that of the Abductor 

 lialluci-. while the outer one joins the tendons of the Adductor transversus 

 hallucis and the Adductor obliquus hallucis prior to their common insertion in a 

 sesamoid bone. Between these two heads the Flexor longus hallucis lies in a 

 ive. 



Origin. — (Plate LIII.) — (1) Inner border of cuboid bone; (2) external 

 cuneiform; (3) prolongation of tendon of Tibialis posticus. 



Insertion. (Plate LIII.) — Inner and outer sides of base of first phalanx 

 of greal toe. 



Action. —Flexes and abducts great toe. 



N i:i;\ i. Supply. Internal plantar. 



Blood Supply.— Internal plantar. 



Astragalus, supplied by dorsalis pedis. One or two centers of ossification. 



Artici LATION. With four bones: (1) tibia, (2) fibula; (3) os calcis, and 

 navicular. 



Astragalus has no muscles attached. 



Os calcis, supplied by posterior tibial, internal and external malleolar. Two 

 centers of ossifk moN. For ossification of tarsus see Plate LIY. 



Artk i LATION. With two bones: (1) the astragalus and (2) cuboid. 



Attachment oi Muscles. Eight: (1) part of the Tibialis posticus; (2) 

 the tendon Achillis; (3) Plantaris; (4) Abductor hallucis; (5) Abductor minimi 

 digiti; (6) Flexor brevis digitorum; (7) Plexor accessorius, and (8) Extensor 

 brevis digitorum. 



Cuboid, supplied by the dorsalis pedis, as are the remaining bones of tarsus. 



( >ssn [( vi [on. ( me center. 



