292 HEALTH AND DISEASE 



Ligaments and tendons, with one or two notable exceptions, are in- 

 elastic, and tear rather than stretch when a force is applied beyond their 

 power of resistance. The apparent elongation in a " break down " is due to 

 the rupture of a number of fibres in more than one place, and not to actual 

 fracture across the ligament. In the case of strain so violent as to dissolve 

 the connection of one part with another, the separation will usually be 

 found close to the bone and not in the middle or seemingly weakest 

 portion. The ligament or tendon tears away from its attachment, or 

 carries with it a thin layer of bone. 



The rarity of complete rupture of a ligament in the middle portion 

 is due to the close weaving of its fibres into a dense rounded bundle, 

 whereas at the ends the fibres spread out to afford a wider attachment 

 to the bones, and are consequently more loosely connected with each 

 other. The great strain put upon certain ligaments, when a draught- 

 horse exerts himself to start a load, is easily borne while the pull is a 

 straight one, but if he be suddenly turned, and a twisting and unequal 

 force is applied to the fibres, rupture is very likely to occur. The force 

 which will extend the fibres of a tendon, or ligament, or muscle will of 

 necessity injure the nerves and blood-vessels concerned in their inner- 

 vation and nutrition; the pain suffered is due to pressure upon, or else 

 laceration of, the former, and the swelling which follows to the escape of 

 fluid from the latter into the structure of the part. 



In the process of repair additional enlargement results from the de- 

 position of new matter, which may be in excess of that actually required. 

 Some of this surplus matter will in time be removed, but it frequently 

 liappens that a considerable amount remains behind as a chronic swell- 

 ing after all active disease has ceased. 



This undue development of reparative tissue will in some instances 

 interfere with the action of the part and impair its function. In whatever 

 manner he attempts it, the surgeon's chief concern is to get rid of super- 

 fluous growth and to restore the parts as nearly as possible to their normal 

 .state. 



SPRAIN OF THE FLEXOR BRACHII 



In the anatomical portion of this work the flexor brachii muscle is 

 described as largely tendinous. It is wholly so in the portion which passes 

 over the bicipital groove in front of the humerus, where it acts as a rope 

 over a pulley before gaining insertion into the head of the radius. Being 

 .situated at the point of the shoulder it is much exposed to injury from 

 blows, as well as to sprains, in performing its office of flexing the forearm 

 upon the humerus. 



