273 



THE MUSCLES OF THE LOWER LIMB. 



The adductor transversals hallucis (transversus pedis) consists of narrow 

 fasciculi of fleshy fibres, placed transversely under cover of the flexor tendons, and 

 arising from the inferior metatarso-phalangeal ligaments of the three outer toes, and 

 from the transverse metatarsal ligament. The fibres of the muscle pass transversely 

 inwards, and are inserted in union with the adductor obliquus into the first phalanx 

 of the great toe. 



Relations. Super ficially it is crossed by the flexor tendons and by the digital nerves ; its 

 deep surface rests upon the heads of the metatarsal bones, the interosseous muscles and the 

 digital vessels. 



Varieties. The slip from the little toe is frequently absent : absence of other slips or of 

 the entire muscle has also been recorded. 



The adductor transversus in early foetal life arises close to the adductor obliquus in the 

 neighbourhood of the bases of the metatarsal bones, and subsequently travels forwards along 



A 



B 



Fig. 264, A. THE DORSAL INTEROSSEOUS 



MUSCLES FROM ABOVE. 



1, 2, 3, 4, the several dorsal interosseoiis muscles 

 in order from within outwards. 



B. THE PLANTAR INTEROSSEOUS MUSCLES 

 FROM BELOW. 



1, 2, 3, first, second, and third plantar inter- 

 osseous muscles ; this figure also shows the long 

 and short plantar ligaments, and the insertion of 

 the tendon of the peroneus longus into the first 

 metatarsal bone. 



the fascia covering the interosseous muscles, so 

 as to acquire its transverse direction across the 

 distal ends of the metatarsal bones. Occasion- 

 ally its separation from the adductor obliquus 

 is not complete, and fibres are found arising- 

 from the deep fascia in the interval between 

 the two muscles. (Huge, Morph. Jahrb., iv, 

 1878.) 



The flexor brevis minimi digit! 



arises by tendinous fibres from the base of 



the fifth metatarsal bone, and from the sheath of the peroneus longus, and termi- 

 nates in a tendon which is inserted into the base and external border of the first 

 phalanx of the little toe. In most cases some of the deeper fibres end on the distal 

 half of the shaft of the fifth metatarsal bone. 



Relations. It is covered partly by the abductor minimi digibi, partly by the plantar fascia. 

 It rests upon the fifth metatarsal bone, and its tendon blends at its insertion with the inferior 

 metatarso-phalangeal ligament. 



Varieties. The portion of the muscle inserted into the fifth metatarsal bone represents an 

 opponens minimi digiti, which is occasionally (3'6 per cent.) found entirely separate from the 

 proper flexor brevis passing to the first phalanx. The insertion into the metatarsal bone is 

 wanting in about 10 per cent. (Gruber, " Beobachtungen," Heft viii, 1887.) 



THE FOURTH LAYER OF THE SOLE includes the dorsal and plantar interosseous 

 muscles, with which the tendons of the tibialis posticus and peroneus longus are 

 sometimes also enumerated. 



The interosseons muscles of the foot, like those of the hand, are seven in 

 number, three plantar and four dorsal ; the plantar are visible only from the under 

 side, while the dorsal muscles are visible both from above and below. Two muscles 

 are found in the second, third and fourth spaces, but only one in the first. 



