1 — Radial styloid process; 2 — Interosseous border; 3 — Shaft of radius; Body of radius, anterior surface; 4 — Anterior border; 5 — Radial tuberosity; 6 — Head of radius; 7 — Articular facet; 8 — Proximal radio-ulnar joint; 9 — Olecranon; 10 — Trochlear notch; 11 — Coronoid process; 12 — Tuberosity of ulna; 13 — Shaft of ulna; Body of ulna, anterior surface; 14 — Interosseous membrane of forearm; 15 — Head of ulna; 16 — Distal radio-ulnar joint; 17 — Anterior surface; 18 — Radius; 19 — Posterior border; 20 — Lateral surface; 21 — Posterior surface;
22 — Medial surface; 23 — Ulna