What is the insertion of the deep digital flexor?

• A. Distal phalanges I-V
• B. Palmar surface of proximal phalanges I-V
• C. Base of metacarpals I-V
• D. Middle phalanges I-V

Answer: (A)

The insertion of the deep digital flexor tendon at the distal phalanges I-V is essential for the flexion of the digits. This tendon runs through the carpal tunnel and continues down the forelimb to attach at the palmar surface of each distal phalanx, allowing for effective flexion of the fingers or toes. This attachment is crucial for grip and manipulation, as it enables the digits to curl and grasp objects.

The other potential choices represent locations where different muscles or tendons might insert, but they are not correct for the deep digital flexor. For instance, the palmar surface of the proximal phalanges refers to a more proximal location where other muscles may have affect, while the base of the metacarpals and the middle phalanges would not enable the distal movement necessary for effective grip. Understanding this anatomy is vital in both clinical and functional contexts.