THE LUMBAR PLEXUS 167 



surface of the proximal part of the femoral shaft. As it passes from its 

 origin to its insertion, it crosses the anterior aspect of the capsule of the 

 hip-joint, and it therefore acts as a flexor of that joint. In addition, 

 it is a weak adductor. 



The Intermediate Cutaneous Nerve of the thigh supplies 

 the skin on the anterior aspect of the thigh and takes part 

 in the formation of the prepatellar plexus. Its area of 

 distribution is overlapped by the medial and the lateral 

 cutaneous nerves and also by the lumbo-inguinal nerve (p. 165). 



The Medial Cutaneous Nerve of the thigh is distributed 

 to the skin over the medial aspect of the thigh and knee. 

 Its branches overlap not only the branches of the intermediate 

 cutaneous but also the branches of the posterior cutaneous 

 (small sciatic) nerve. 



The Saphenous Nerve accompanies the femoral artery in 

 the proximal two-thirds of the thigh. It pierces the deep 

 fascia opposite the adductor tubercle and descends along the 

 medial aspect of the leg. Finally it terminates about the 

 middle of the medial border of the foot. 



PARALYSIS OF THE FEMORAL NERVE is a very uncommon 

 condition. When the psoas major and the iliacus are involved 

 in addition to the quadriceps, the sartorius and the pectineus, 

 the movements of flexion at the hip and extension at the 

 knee are greatly weakened, but they are not impossible. 

 When the thigh is hyperextended and rotated laterally, the 

 adductors (obturator nerve) and the tensor fasciae latae 

 (superior gluteal nerve, p. 172) can produce flexion of the hip 

 and the latter muscle alone is able to extend the knee-joint. 

 On this account, the patient may be able to walk with the help 

 of a stick. 



When the femoral nerve is completely divided, sensory 

 disturbances occur in the distal part of the antero-medial 

 aspect of the thigh, and in the medial aspect of the leg and 

 ankle, in the area supplied by the saphenous nerve. It is 

 in the latter area that the greatest alterations in sensibility 

 occur, but deep sensibility is not affected. 



