part of part of Homo sapiens humerus surface groove radial groove of humerus 2026-03-19T00:00:00Z A surface groove spiraling obliquely across the posterior surface of the humeral shaft from the medial to the lateral side, separating the origins of the medial and lateral heads of the triceps brachii. It transmits the radial nerve and the deep brachial artery, and is also termed the musculospiral groove. David Osumi-Sutherland