PARALYSIS OF THE ANTERIOR CRURAL NERVE i6i 



plexus to the position where it disappears between the rectus femoris 

 and vastus internus muscles the nerve does not pass in intimate relationship 

 to any bone, but is related to comparatively soft structures. Hence it 

 is not surprising that we have quite a number of different theories as to 

 the causation of paralysis of this nerve. 



A number of cases of paralysis are associated with attacks of 

 haemoglobinuria. Such cases are readily understood, since the psoas 

 and iliacus muscles are involved in this disease, and the intimate relation- 

 ship of the nerve to these muscles has been pointed out. 



Moreover, it has been proved experimentally by Goubaux, who 

 divided the nerve as it passes between the rectus femoris and vastus 

 internus, that section of the nerve leads to the production of those 

 symptoms of muscular paralysis which are observed in cases of 

 hemoglobinuria. 



Tumours and abscesses have also been discovered along the course of 

 the nerve in making post-mortem, examinations of animals which had 

 been subjects of this affection. 



The condition has also been attributed to blows received over the 

 region of the thigh. A study of the anatomical position and relation- 

 ships of the nerve will immediately make evident the improbability of this, 

 for the nerve is placed in a position which is decidedly favourable to its 

 protection. Others have considered undue stretching of the nerve to be 

 a common cause. Whilst admitting that some nerves are particularly 

 prone to injury of this kind — such, for instance, as the suprascapular 

 nerve, which appears to be too short for the distance it has to travel when 

 the movements of the part are taken into consideration — the same 

 cannot be said regarding the anterior crural nerve, the disposition of 

 which appears to be such as will permit of a considerable degree of 

 stretching of the parts without throwing great tension on the nerve itself 

 There are still numerous cases of this affection the cause of which 

 remains in obscurity. In connection with this point it occurred to the 

 author, in examining the course of the nerve, that, owing to its relation- 



