THE LEGS AND THEIR EFFECTS 



to pelvis, lie the great muscles which move the fore 

 and hind limbs, and which are the principal agents 

 in locomotion. Of these the latissimus dorsi car- 

 ries the arm upward and backward, the longissi- 

 mus dorsi, when it acts alone, is a powerful extensor 

 of the vertebral column, and the deep pectoralis, 

 attached at the angle of the shoulder, draws the 

 whole fore limb backward. The student desiring to 

 understand more fully the attachments, relations, 

 and actions which are effected by pressure of the 

 rider's legs, should consult some standard work on 

 the anatomy of the horse. 



It is, then, easy to understand that the rider's 

 legs affect first of all the horse's hair, skin, pannicu- 

 lus carnosus, and abdominal tunic, all of which have 

 nothing to do with locomotion; while the great 

 pectoralis and its adjuncts, the latissimus dorsi, 

 and the muscles of the haunches and hind limbs, 

 are either affected only secondarily or remain 

 unimpressed. But the first contact of the rider's 

 legs is for the horse rather unpleasant than other- 

 wise. It takes, therefore, patient teaching to 

 accustom the untrained animal to endure this 

 contact without anxiety, nervousness, or fear. Only 

 after the horse, standing quiet and calm, supports 

 the pressure of the legs on all parts of the body, 

 from as far forward as the rider can reach to as far 

 backward, has the time come for teaching the 

 significance of this contact for the more important 

 muscles of locomotion, such as the great pectoralis. 



