This presents the form of a broad membranous or capsular ligament stretching over the front of the true hock-joint. It is lined by synovial membrane, and is that portion of the capsule which bulges in what is termed "bog-spavin". The anterior ligament is united to the lower part of the tibia above, it is attached below to the astragalus and the small bones of the hock in front, and at the sides it blends with the lateral ligaments.