SECTION IT I. 

 LAMENESS IN THE FORE LEG. 



Anatomo-Physiological Review of parts of the Fore Leg. 



For supporting weight, whether tlie suhjeet is at rest or in 

 motion, the bony eolunin of the leg, together with attached liga- 

 ments, tendons and muscles, is wonderfully well adapted by na- 

 ture for the function which they perform. The several bones 

 which go to make up the supportive portion of the leg, are so 

 joined at their points of articulation, that a minimum degree 

 of strain is put upon each attachment. 



The upper third of the scapula, with its cartilage of prolonga- 

 tion, is sufficiently broad and flattened that it fits snugly against 

 the tliorax without necessity for a complicated method of attach- 

 ment — the clavicle l)eing absent, attachment is muscular. 



Smith^ has very aptly stated that : 



"It seems quite legitimate to regard the muscular union between 

 the thorax and forelimb as a joint. There are no bones resting 

 on each other, no synovia ; l)ut where the scapula has its largest 

 range of movement there is a remarkable amount of areolar 

 tissue, which renders movement easy. The whole central area 

 beneath the scapula and humerus not occupied by muscular at- 

 tachment, is filled with this easy-moving, apparently gaseously 

 distended, crepitant, areolar tissue over which the fore legs glide 

 on the chest wall as freely as if the parts were a large, well 

 lubricated joint. ' ' 



The scapulohumeral articulation (shoulder joint) is an 

 enarthrodial (ball and socket) joint but because of its being 

 held more or less firmly against the thoracic wall by muscular 

 and tendinous attachment, and because a part of this attachment 

 affords a means of support for the body itself, there is no need 

 for binding ligaments and movement is possible in all directions 

 even though restricted as to extent. 



iManual of Veterinary I'hysiology, by Major-General F. Smith, page .590. 



55 



