Interosseous 'muscle' is also called the

• A. SDF
• B. Suspensory ligament
• C. DDF
• D. Common digital extensor

Answer: (B)

In horses, the interosseous muscle isn’t a typical large muscle in the limb. Its tendon expands distally and becomes a strong fibrous structure that blends with the proximal sesamoid bones, forming the suspensory ligament. This suspensory ligament is a central part of the stay apparatus, resisting overextension of the fetlock when the limb bears weight and helping to support the limb’ s load with less muscular effort.

Other structures listed are different: the superficial digital flexor and the deep digital flexor are flexor muscles that bend the digits, while the common digital extensor extends the digits. The key idea is that the interosseous muscle is the same structure as the suspensory ligament.