Fifth metacarpal bone Fifth metacarpal bone The fifth metacarpal bone (metacarpal bone of the little finger or pinky finger) is the most medial and second-shortest of the metacarpal bones. It presents on its base one facet on its superior surface, which is concavo-convex and articulates with the hamate, and one on its radial side, which articulates with the fourth metacarpal. On its ulnar side is a prominent tubercle for the insertion of the tendon of the extensor carpi ulnaris muscle. The dorsal surface of the body is divided by an oblique ridge, which extends from near the ulnar side of the base to
Bertram A. Bone solving the many problems which confronted him." During the Japanese Attack on Pearl Harbor on December 7, 1941, Bone was stationed on Hawaii and coordinated the trucks with ammunition. In May 1942, Bone was transferred to the staff of South Pacific Island Base Inspection Board under Rear Admiral Richard E. Byrd and travelled to the South Pacific Area as a member of the inspecting party. He was promoted to the rank of colonel on July 24, 1942. During September of that year, Bone was transferred to Washington, D.C. and appointed Chief of the Gunnery Section, Division of Plans and Policies