What structure forms the posterior boundary of the carpal tunnel?

What structure forms the posterior boundary of the carpal tunnel?

• A. Flexor digitorum profundus tendon
• B. Flexor retinaculum (transverse carpal ligament)
• C. Palmar aponeurosis
• D. Extensor retinaculum

Answer: (B)

The structure that forms the boundary at the back of the carpal tunnel is the flexor retinaculum (transverse carpal ligament). This fibrous band stretches across the carpal bones and creates the tunnel through which the flexor tendons and median nerve pass. In this framing, the ligament defines the posterior edge of the space, separating the contents of the tunnel from the structures of the palm. The other options don’t serve as the boundary of the tunnel: the flexor digitorum profundus tendons travel inside the tunnel; the palmar aponeurosis lies in the palm itself; and the extensor retinaculum is on the dorsal wrist and not part of the tunnel boundary.

The structure that forms the boundary at the back of the carpal tunnel is the flexor retinaculum (transverse carpal ligament). This fibrous band stretches across the carpal bones and creates the tunnel through which the flexor tendons and median nerve pass. In this framing, the ligament defines the posterior edge of the space, separating the contents of the tunnel from the structures of the palm. The other options don’t serve as the boundary of the tunnel: the flexor digitorum profundus tendons travel inside the tunnel; the palmar aponeurosis lies in the palm itself; and the extensor retinaculum is on the dorsal wrist and not part of the tunnel boundary.