POINTS FROM WHICH THE PROPORTIONS ARE STUDIED. 383 



possess. It would therefore be fastidious to reproduce here all the 

 details into which we have entered ; our point of view now is much 

 more general. 



We will limit ourselves to the following short resume: 



1st. The articular angles are alternately closed and opened during 

 locomotion. 



Their closing should dispose their branches in such a manner as to 

 shorten as much as possible the whole member in order to prepare it 

 for an attitude of considerable extension. 



Their opening, lengthening the locomotory column, should permit 

 the inferior extremity of the latter to acquire an extreme position, 

 as far removed as possible from the original position, in order that 

 the step may have a great length and the impulsion be of long dura- 

 tion. 



2d. The extent of the articular action is intimately dependent 

 upon the respective position of the osseous segments during the regular 

 station. In princi2)le, the original separation of these latter increases 

 it, and their approximation diminishes it. 



3d. In order that the articular action may produce the greatest 

 amount of useful effects, it must be accomplished in such a manner 

 that the two extremities of the member may be separated, at the time 

 of extension, in a very oblique direction and not according to the 

 vertical or any other direction approaching the vertical. It is under 

 these conditions that the length of the step and the impulsive power 

 acquire their highest limit. It is in this case also that the impulsion 

 is most efficaciously transmitted, — that is to say, following a trajectory 

 close to the horizontal, having a forward movement and not an upward 

 one. 



4th. The degree of inclination of the locomotory segments is there- 

 fore capable of influencing the action of the articular angles in two 

 ways : either by modifying its extent or modifying its efficacy. The 

 obliquity of these segments should therefore satisfy this double require- 

 ment, — viz., increase the efficacy of the articular action without dimin- 

 ishing its extent. 



5th. To do this we know that the superior segments, the shoulder 

 and the croup, little movable, should rather tend towards the horizontal, 

 in order to ac(piire more length without increasing beyond measure 

 the height, to facilitate the forward and backward movement of the 

 inferior regions, and give them the freedom of extending themselves 

 effectively to pass over the ground or communicate the impulsion. 



This horizontality of the shoulder and the croup naturally implies 



