Connects SDF muscle tendon to palmar ligament

• A. DDF check ligament
• B. SDF check ligament
• C. Lacertus fibrosus
• D. Collateral ligaments

Answer: (A)

In the forelimb stay apparatus of the horse, tendons of the long digital flexors are tethered to palmar structures so that weight bearing helps support the limb without active muscle effort. The structure that directly links the deep digital flexor tendon to the palmar ligament is the DDF check ligament. It binds the deep digital flexor tendon to the palmar carpal area, creating a tether that helps distribute tension and stabilize the limb when the animal is standing. This linkage between the deep digital flexor tendon and the palmar ligament is what establishes the connection described in the question, making it the most appropriate choice. The lacertus fibrosus binds the superficial digital flexor tendon to other structures like the biceps tendon and extensor carpi radialis, not to the palmar ligament, and collateral ligaments are joint stabilizers rather than direct connectors between the SDF tendon and the palmar ligament.