ARTICULATION OF THE OS CALCIS AND CUBOIDES. 267 



flexor longus digitorura. Below it is also in contact with the 

 tendon of the tibialis posticus, and above with the head of the 

 astragalus, which it in part supports. y 



The external is at the outer side of the last ; it arises from the 

 under surface of the greater apophysis of the os calcis, and is 

 inserted upon the under internal surface of the os naviculare. 



The ligaments which pass from the anterior internal extremity of the os calcis 

 to the os naviculare, and support the head of the astragalus, ought to be 

 observed with attention during the examination of this joint. 



Articulation of the Os Calcis and Cuboides. 



The articulating surfaces of this joint are arranged in the 

 usual manner. 



There are two additional ligaments : one placed on the upper, 

 and the other on the under surfaces of the bones. The upper 

 ligament is thin ; but the under ligament is one of the strongest 

 of the foot ; and its fibres are blended with those which form 

 the sheath for the tendon of the peroneus longus, as it passes 

 along the groove in the cuboides. 



These ligaments are called the superior and inferior calca- 

 neo-cuboid. The latter is by some considered as consisting of 

 two ligaments, the short and long. 



The superior passes from the upper anterior surface of the 

 os calcis to the adjoining surface of the os cuboides. 

 The inferior is the strongest ligament of the foot. It arises 

 from the inferior back part of the os calcis, and part of its 

 fibres are inserted upon the oblique ridge or the tendon of the 

 peroneus longus which traverses the under part of the os cu- 

 boides. This part is sometimes called the short inferior calca- 

 neo-cuboid ligament. The greater part of the fibres of this 

 ligament, pass beyond the ridge, and are inserted in fasciculi 

 upon the basis of the third and fourth metatarsal bones. These 

 subtend the groove, in which passes the tendon of the peroneus 

 longus muscle, and constitute the long inferior calcaneo-cuboid 

 ligament. 



The other bones of the foot are united in general by dorsal and 

 plantar ligaments like the corresponding bones of the hand. 



