What is the insertion point of the common digital extensor?

• A. Olecranon tuber
• B. Distal phalanx II-V
• C. Caudal border of the scapula
• D. Radial and ulnar tuberosity

Answer: (B)

The common digital extensor has its insertion point at the distal phalanx of the second to fifth digits. This muscle is responsible for extending the digits, allowing for movements such as lifting the toes or fingers. By inserting at the distal phalanx, the common digital extensor exerts its action effectively, enabling not just extension but also contributing to the overall functionality of the limb during various activities.

The other options do not represent the correct insertion point for the common digital extensor; they reference structures associated with different functions or muscles. For example, the olecranon tuber is associated with the triceps muscle, while the caudal border of the scapula pertains to shoulder movements and the radial and ulnar tuberosities are linked to muscles involved in flexion rather than extension of the digits. Recognizing that the distal phalanx is the terminal bone structure of the digits helps in understanding how this muscle contributes to limb movements.