300 INFERIOR EXTREMITY 



slips, and between these the tendon of the flexor longus 

 proceeds forwards to its insertion into the plantar aspect 

 of the base of the ungual phalanx. The two slips of the 

 tendon of the flexor brevis are joined by their margins on 

 the deep surface of the long flexor tendon, and then separate 

 again to obtain insertion into the sides of the shaft of the 

 second phalanx about its middle. 



Tendon of the Flexor Hallucis Longus. After giving its 

 slip to the tendon of the flexor digitorum longus, the tendon 

 of the flexor hallucis longus is prolonged forwards to the 

 great toe. On the plantar aspect of the hallux it is retained 

 in place by a flexor sheath, and finally it is inserted into 

 the base of the terminal phalanx. 



M. Quadratus Plantae (O.T. Flexor Accessorius). This 

 muscle takes a course straight forwards from the heel, and 

 acts as a direct flexor of the toes. It also tends to bring the 

 tendons of the long flexor muscle into a line with the toes upon 

 which they operate. It arises by two heads which embrace 

 the calcaneus and the long plantar ligament. The medial 

 head, wide and fleshy, springs from the medial concave 

 surface of the calcaneus ; the lateral head, narrow, pointed, 

 and tendinous, takes origin from the lateral surface of that 

 bone, and also from the long plantar ligament. The 

 quadratus plantae is inserted into the tendon of the flexor 

 digitorum longus in the middle of the sole. It is supplied 

 by a branch from the lateral plantar nerve. 



Mm. Lumbricales. The lumbrical muscles of the foot are 

 not so strong as the corresponding muscles in the palm of the 

 hand. They are four in number, and arise from the tendons 

 of the flexor digitorum longus. The three lateral lumbricals 

 spring from the adjacent sides of the tendons between which 

 they lie ; the first or most medial muscle takes origin from the 

 medial side of the tendon of the long flexor which goes to the 

 second toe. The slender tendons of the lumbrical muscles 

 proceed to the medial sides of the four lateral toes, and are 

 inserted into the expansions of the extensor tendon on the 

 dorsal aspect of the proximal phalanges. The first or most 

 medial lumbrical is supplied by the medial plantar nerve : the 

 others by the lateral plantar nerve. 



Dissection. To bring the third layer of muscles into view the following 

 dissection must be made : Divide the two heads of the quadratus plantse 

 and draw the muscle forwards from under the lateral plantar vessels and 



