Anatomy of Skeleton 



Turning now to the transverse arch, we find that it is highest in the front part of 

 the tarsus. If, then, the segments could be tied together here, they would act under 

 the best possible conditions for holding up the structure. 



So we find strong transverse ligamentous fibres in 

 this situation, fastening together the cuneiforms, the 

 cuboid, and the scaphoid, and such fibres are necessarily 

 on the plantar side of the bones and between them, 

 nearer their plantar than their dorsal parts, for the 

 nearer the ties are to the concavity the more effectively 

 do they hold up the arch : thus we might almost expect 

 to find that the articular surfaces between the bones 

 arranged transversely would be nearer the dorsal than 

 the plantar margins of their side aspects. In the same 

 way the high arch is easily held by ties between its 

 pillars, and the peroneal tendon passing under one 

 pillar to be fastened to the other acts well as an 

 extensible tie. 



Thus this transverse arch is easily held up by the 

 first and second of the two classes of supports, and 

 the third, which would find difficulty in securing 

 attachment away from the arch, is really not required 

 and does not exist. 



If we now consider the three arches and their 

 supports together, we obtain an idea of the meaning 

 of the numerous ligaments which appear to run in every 

 direction on the plantar surface of the bones (Fig. 143) , 

 and we can divide them according to the three arches 

 they support and their consequent position, direction, 

 and strength. But it must not be forgotten that, 

 although the supporting bands of these arches can be 

 analysed separately in this way, the three sets are so 

 connected naturally in function, and in some ways in 

 community of support, that failure in one arch will of 

 necessity lead to consequent strain and failure in the 

 others : in practice, one arch should never be considered 

 to stand alone. 



Observe now that the inner arch does not rest at its 

 front end equally on the heads of the three inner 

 metatarsals : the first metatarsal is the main weight 

 supporter, the others, like the rest of the metatarsus, 

 acting more as balancers and only taking weight such as 

 is necessary in keeping the balance of the body on the 

 " ball of the big toe." Again, on the outer side the 

 arch, in spite of its strong ligaments, is so low that it will 

 flatten down, under pressure, enough to bring the 



metatarsal edge on the ground, and the outer arch is then shortened, so that its 

 anterior p ; llar becomes practically the base of the fifth metatarsal. Under these 

 circumstances the arch of the metatarsus, not having to carry much weight, does not 

 require strong ligamentous support : it can be easily restrained from splaying out by- 

 transverse connections at the distal end, and here we find the intermetatarsal transverse 



FIG. 143- Scheme to show the 

 general arrangement of liga- 

 ments. These can be divided 

 into those of the transverse 

 and longitudinal groups. The 

 transverse fibres are found in 

 the highest part of the trans- 

 verse arch, where they can 

 exercise most effect ; thus 

 they are found connecting the 

 cuneiforms, scaphoid, and 

 cuboid, and their lower fibres 

 connect the metatarsals. The 

 longitudinal fibres are 

 strongest along the outer 

 arch, where a. and ft. are long 

 and short plantar ligs., while 

 the shorter bands on the inner 

 side include c., calcaneo-sca- 

 phoid, d., scapho-cuneiform, 

 and e., weaker cuneiform- 

 metatarsal fibres. The inter- 

 nal lateral lig. reaches the 

 sustentaculum by its middle 

 fibres, and in front of this runs 

 into the calcaneo-scaphoid set 

 and thus into the scaphoid ; 

 observe that the tendon of 

 Tibialis posticus sends its ex- 

 pansion to the cuboid under 

 this part and thus supports 

 the highest part of the inner 

 arch. 



