The deep flexor tendon inserts at which structure?

• A. Extensor Process Of The Coffin Bone
• B. Semi Lunar Crest Of The Coffin
• C. Navicular Bone
• D. Proximal Phalanx

Answer: (B)

The deep digital flexor tendon attaches at the semilunar crest on the coffin bone (distal phalanx). This crescent-shaped ridge on the plantar (palmar) surface serves as the insertion site that anchors the tendon so it can flex the distal joint. The extensor process is where the extensor tendon attaches, not the deep flexor; the navicular bone is part of the tendon’s path but not its insertion point; and the proximal phalanx is positioned farther up the limb, not the insertion site for this tendon.