579b0a37_ses_and_ponies_on_the_internet__3
[0] Deep digital flexor tendon ( DDFT) [1] Deep digital flexor muscle starts at the ulna [2] Underneath the pedal bone [4] Passes over the back of the knee, held in place by the check ligament, passes over the sesamoid bones and fans out over the navicular bone. [3] 
Flexes the joints of the lower leg, prevents the fetlock from over extending, together with the check ligaments helps with weight bearing.
Equiworld - Equestrian Information - tendons and ligaments of the lower leg - horses and ponies on the internet
3