952 DISPLACEMENT OF THE BICEPS FEMOR1S MUSCLE. 



A ten-year-old grey gelding had fallen in front of the carriage and was 

 lame, bul in the stable showed nothing unusual. A careful examination of 

 the pelvis, proved, however, that the left buttock was abnormally flat at 

 the height of the tuber ischii. Seen from the side, the right buttock pro- 

 jected considerably further than the left, the flattening, which was about 

 1 to 2 inches in size, was most marked over the tuber ischii, and lost itself 

 above and below, as well as externally and internally. The right tuberosity 

 could be distinctly felt, but the left was indistinguishable ; a soft mass of 

 muscle occupied its position, and the bone could only be felt in the depths. 

 Around the trochanter the muscles of the quarter were slightly prominent, 

 so that when seen from behind the left quarter appeared broader than the 

 right. Lower down the middle line of the perineum was thrust about an 

 inch to the left. 



At a walking pace there was moderate supporting leg lameness of the 

 left limb, which was abducted both when loaded and when freely swinging. 

 By placing the hand on the quarter, close behind the upper trochanter, 

 during movement, it was possible at the moment the limb was relieved 

 of weight to detect a sensation as though a cord moved from behind 

 forvvards, and then immediately glided back again. Careful observation 

 detected this jerking movement of the biceps femoris muscle, over a region 

 extending from a point about 4 inches above and to the side of the upper 

 trochanter, as far as the middle third of the femur. 



The accident was probably due to old fracture of the tuber ischii, 

 resulting in the point of insertion of the biceps femoris muscle being torn 

 away and the muscle being displaced in a forward direction, thus differing 

 from the condition usual in cattle, where displacement is backward. 



Feyer describes a case which may have been due to displacement of the 

 biceps femoris muscle. The horse was in heavy work. When at rest, weight 

 was equally placed on both hind limbs, but the left limb was held a little 

 further from the middle line of the body. On the outer side of the left 

 thigh was a depression about 8 inches long and 2 deep, beginning in front 

 of and below the biceps femoris muscle, and extending obliquely down- 

 wards and backwards, becoming gradually more and more shallow. Behind 

 this, and corresponding to it in extent, was a swelling in the position occupied 

 by the anterior edge of the semi-tendinosus muscle. The swelling seemed 

 on palpation like a mass of tense muscle. The skin could be lifted and 

 moved over the surface of the depression ; pain and increased warmth 

 were absent. In walking the leg was advanced with a circular sweep and 

 set down in a position of abduction. The stride was shorter than that 

 of the sound leg, and the leg was lifted and advanced soon after it passed 

 the vertical position. The horse was not very lame when trotting, though 

 the peculiar gait was more marked. As the horse was still able to do the slow 

 work in which it had been engaged no treatment was carried out. 



IX.— HIP LAMENESS. 



Not infrequently the symptoms of hind-leg lameness are so ill- 

 defined that it is impossible to detect the exact cause, in addition to 

 which pathological changes occur in the quarter and upper parts 

 of the hind limb, especially around the hip-joint, the exact nature 



