354 



THE AKTICULATIONS OE JOINTS. 



It is doubtful whether lateral movement at the ankle-joint can be obtained by any natural 

 movement of the foot, although it is generally believed that in the position of partial extension 

 a small amount of side-to-side movement may be produced by the application of external force. 

 This apparent play" of the ankle-joint during extension "is really due to oscillation . of the 

 small bones of the foot on each other, largely of the navicular on the talus, but also of the 

 cuboid on the calcaneus. Excessive mobility of these latter is restrained by an important 

 function of the posterior tubercle of the cuboid which locks into a notch in the caleaneus " 

 (Blake). 



ARTICULATIONES INTERTARSE.E. 



The intertarsal joints are all diarthroses in which the gliding movement is 

 characteristic, as in the carpus. With the view of obtaining a proper conception 

 of the many beautiful mechanical principles involved in the construction of the foot, 

 it is necessary to study these articulations with considerable attention to detail. 



Fibula 



Posterior ligament 

 of lateral malleolus 



Articular surface of talus 

 Posterior talo-fibular 

 ligament of ankle 



Calcaneo-fibular 



ligament of ankle 



Posterior talo-calcaneal 



ligament 



Calcaneus 



Tibia 



Anterior ligament of lateral malleolus 



Articular surface of talus 



Anterior talo-fibular ligament of ankle 



Dorsal talo-navicular ligament 

 Talo-navicular joint 



Lateral calcaneo-navicular ligament 

 Dorsal cuneo-navicular 

 & naviculo-cuboid ligaments 

 ? iv^X* 211 ' 1 cuneiform 



3rd cuneiform 



Cuboid 



Dorsal calcaneo-cuboid ligament 

 Calcaneo-cuboid joint 

 Tendon of peronseus longus 

 Interosseous talo-calcaneal ligament 

 Talo-calcaneal joint 

 Lateral talo-calcaneal ligament 



FIG. 324. LIGAMENTS ON THE LATERAL ASPECT OP THE ANKLE-JOINT AND ON THE DORSUM OF THE TARSUS. 



Articulatio Talocalcanea. The talus and calcaneus articulate with each 

 other in the talo-calcaneal joint. 



This joint is situated between the inferior facet on the body of the talus and 

 a corresponding facet on the superior aspect of the posterior part of the calcaneus. 

 On each bone the articulation is limited in front by a wide, deep groove which 

 runs obliquely across each bone from the medial to the lateral side and forwards. 



The supporting and investing ligaments form the fibrous stratum of an articular 

 capsule, consisting for the most part of short fibres, but the joint derives additional 

 strength from the calcaneo-fibular ligaments of the ankle-joint. The fibrous 

 stratum of the capsule is subdivided into, the following talo-calcaneal bands : 



The ligamentum talocalcaneum anterius consists of a band of short fibres 

 placed immediately in relation to the anterior end of the deep groove which 

 bounds the articular facets. They are attached to the an tero- lateral aspect of 

 the neck of the talus, from which they extend downwards to the adjacent superior 

 surface of the calcaneus. 



The ligamentum talocalcaneum laterale (Fig. 324) is in continuity with the 

 posterior border of the preceding ligament, and it is placed parallel to, but on 



