STRAIN OF TSOM MUSCLES. 243 



refnonsToriglnating at the heads of the last ribs and last dorsal 

 vertebrai, extending in a backward direction under the bodies of 

 the lumbar vertebr?e. to the ilio-pectineal eminence on the brim 

 of the pelvis, and the internal trochanter of the femur. Their 

 action is to bend the haunch upon the pelvis, to draw it forward 

 in progression, or while the hind quarters are stationary and 

 fixed points, their action produces that appearance ^.cjdled 

 "reached back." 



It is important to remember the action of these muscles, 

 for when injured they cease to act, and tlie haunch will be 

 thrown into the opposite condition of " roached back;" and 

 from this circumstance the injury may be readily distinguished 

 from azoturia. 



Strain of these muscles is caused by injury, such as " being 

 cast in the stall," or by any other accident capable of producing 

 violent extension of them ; hence arises tlie difficulty of deter- 

 mining between it and " broken back." It may, however, be 

 distinguished from tho paralysis of broken back by the power of 

 flexing and extending tlie limbs being still retained by the ani- 

 mrl wliilst it is lying down ; tliere may be inabihty to rise from 

 the ground, as the psote muscles assist very materially in that 

 operation ; but when raised by means of slings from the recum- 

 bent position, an<l when the hind feet are firmly placed upon 

 the ground, tlie horae is able to stand moderately well, and 

 command the movements of the limbs to some extent, althougli, 

 there is always a tendency to knuckling over at the^fetlock.- 

 jointa. 



The muscles of one side may be injured; in such lalcase^thd 

 loss of power is limited to one side only. 



If the injury be not sufficiently severe to destroy the-power 

 of rising, it will be seen that, when the horse is made to walk, ha 

 drags his limbs or trails them to some extent. There is scarcely 

 any elevation of the feet or flexion of the joints, and^*grea^ 

 tendency is shown to knuckle over at every step. 



Examination per rectum will reveal heat, tendernessT^nd 

 swelling under the spine ; and m the majority of cases that 

 have come under my observation, external swelling around, ther 

 rectum and perinaeum, or vagina, if the patient be a mare, will! 

 make its appearance in the course of a few hours iitftexltlici! 

 accident. 



