1888 HUMAN ANATOMY. 



Movable Kidyiey. — The extent of the normal kidney movement — of ascent during 

 expiration or while lying supine, and of descent during inspiration or while standing 

 erect — does not, on an average, much exceed an inch in the vertical direction. There 

 may also be a slight lateral movement. When this limit is distinctly and greatly 

 overpassed the condition known as ' ' movable kidney' ' results. The normal kidney 

 is usually not palpable below the costal arch. Occasionally the lower end of the 

 right kidney may be felt there just external to the rectus muscle. In emaciation the 

 lower ends of both kidneys may be palpable. 



Three degrees of abnormal mobility have been arbitrarily but usefully agreed 

 upon for purposes of description : ( i ) The lower half may be felt by bimanual pal- 

 pation — the fingers of one hand being pressed into the ilio-costal space posteriorly, 

 and of the other, into the subcostal region anteriorly — during deep inspiration. 

 (2) The greater part of the kidney or the whole organ may be felt during deep 

 inspiration, but ascends under cover of the ribs and liver during expiration. (3) The 

 whole kidney descends and can be retained between or below the examiner's fingers 

 during the respiratory movements (Morris). 



The most important factors in holding the kidney in its normal position in the 

 renal fossa (page 1874) are : («) the perirenal fascia, which through its attachment to 

 the transversalis fascia and to the perinephric fat, in conjunction with i^b) the peri- 

 toneum, where that covering exists, prevents any undue mobility; (r) the renal vessels, 

 which must correspond in length to the radius of the circle of movement of the kidney 

 and, to an extent, resist elongation ; i^d) intra-abdominal pressure, which, through 

 the upward thrust of the more mobile viscera, adds to the support that i^e) they and 

 their attachments give to the viscera in the upper zone of the abdomen ; {J") the 

 shape of the renal fossae, which, like the kidneys themselves, are somewhat narrower 

 at their lower extremities. 



Undue mobility of the kidney is thus favored by (a) congenital absence of the 

 peritoneal support (floating kidney, — vide supra') ; ((5) diminution of the tension of 

 the peritoneum and perirenal fascia from absorption of perinephric fat ; (r) repeated 

 jars and jolts, as from jumping or falling, or from coughing or straining, that tend 

 to elongate the renal vessels as well as to stretch the peritoneum and its attachments 

 and thus increase both the retroperitoneal space in which the kidney moves and the 

 radius of the arc of its movement ; (a') pregnancy, the removal of intra-abdominal 

 tumors or of accumulations of fluid, or other conditions that produce laxity and 

 weakness of the abdominal walls ; {^e) ptosis of other viscera, acting either by their 

 push from above (liver, spleen) or their drag from below (colon) ; or (y) general 

 muscular weakness, acting not only by reason of the associated lack of tonicity of 

 the abdominal wall, but also through the modification in shape of the renal fossae, 

 the depth of which depends, c ceteris paribus, on the development of the loin muscles, 

 and especially of the psoas and quadratus lumborum. 



A careful study of the body-form in its relation to movable kidney seemed to 

 show (Harris) that a relative diminution in the capacity of the middle zone or area 

 of the body-cavity (containing the liver, stomach, spleen, pancreas, and larger por- 

 tion of each kidney), either original or acquired (as from tight lacing), acts by forcing 

 the liver and spleen downward upon the kidneys, and at the same time depriving 

 them of the support afforded by the narrowest or most constricted portion of the 

 parietes of this zone, which narrow portion is then above the centre of the kidney 

 instead of below it, as it should be normally. 



Consideration of the above-mentioned anatomical factors makes clear the greater 

 frequency (80 per cent.) of movable kidney in women than in men. It should be 

 added that in women the renal fossae are normally shallower and less narrowed at the 

 lower ends than in men, the depth and the narrowing depending, as has been said, 

 upon muscular development. It will be understood, too, why among the women 

 who suffer from this condition is found a so considerable proportion who are thin and 

 round-shouldered, with long, curved spines and flattening and adduction of the lower 

 ribs, or who have had several children, or one difficult labor, or an exhausting illness 

 attended by emaciation, or have been addicted to tight lacing. In both sexes the 

 history of a violent fall or of a chronic cough is not infrequent. 



Movable kidney is thirteen times more frequent on the right side than on the 



