MUSCLES OF THE CROUP 339 



MUSCLES OF THE CROUP 



Superficial Gluteus. The most superficial muscle of the croup. It 

 is V-shaped, and situated immediately beneath the gluteal fascia. 



Origin. By its anterior arm from the point of the ilium or haunch- 

 bone. By its posterior arm from the gluteal fascia. Passing downward 

 these two branches converge and unite. 



Insertion. Into the trochanter minor externus, a bony prominence on 

 the outer face of the thigh-bone. 



Action. To abduct or draw the thigh outward. 



Middle Gluteus. This is a thick, broad, fleshy muscle to which the 

 croup owes its characteristic roundness. In a forward direction it extends 

 for some distance over the loins, and terminates behind in the upper 

 extremity of the femur or thigh-bone. 



Origin. (l) From the superior surface of the longissimus dorsi in front. 

 (2) From the superior or dorsal surface of the ilium, and the sacro- sciatic 

 and the ilio-sacral ligaments. 



Insertion. By three branches into the upper extremity of the femur. 



Action. To extend the thigh on the pelvis and incline the entire limb 

 outwards. When the hind limbs are fixed it assists in rearing. Acting 

 from before as a fixed point it takes part in kicking. 



The Deep Gluteus. A small but strong muscle placed between the 

 one last described and the hip-joint. 



Origin. From the superior surface of the ilium and from the ischium 

 above the hip-joint. 



Insertion. Into the margin of the lower division of the great trochanter 

 of the femur. 



Action. To abduct the limb and rotate it inwards. 



MUSCLES OF THE HIP AND THIGH 



Tensor Vaginae Femoris. A thin triangular muscle situated in front 

 of the thigh, having its base directed downwards. By its posterior border 

 it is intimately connected with the anterior branch of the superficial gluteal 

 muscle, and below it gives off a somewhat broad aponeurotic tendon. 



Origin. From the external angle of the ilium or haunch-bone. 



Insertion. Into the fascia lata, or membrane investing the muscles of 

 the second thigh. 



Action. It braces up the muscles and flexes the thigh on the pelvis. 



Rectus Femoris (Straight Muscle of the Thigh). This is a thick, 

 rounded muscle covering the front of the femur. 



