Dupuytren Contracture — Ring + Little Finger Flexion

A 58-year-old man of Northern European descent presents with progressive inability to extend his ring and little fingers. On examination, he demonstrates the clinical finding marked as **C** in the diagram — flexion contracture of the 4th and 5th digits. He cannot lay his hand flat on a table. Which of the following best explains why the ring and little fingers are most commonly affected first in Dupuytren contracture?