Medical Term for Side-to-Side Wrist Motion
The medical term for side-to-side motion of the wrist is radial-ulnar deviation (also called radioulnar deviation or radial-ulnar flexion). 1
Anatomical Description
- Radial deviation refers to movement of the hand toward the thumb side (radial side) of the forearm 1
- Ulnar deviation refers to movement of the hand toward the little finger side (ulnar side) of the forearm 1
- This motion occurs in the frontal plane and is distinct from flexion-extension, which occurs in the sagittal plane 1
Normal Range of Motion
- The typical range of radial-ulnar deviation in healthy individuals is approximately 55 degrees total 1
- This motion is naturally coupled with flexion-extension movements, meaning pure isolated radial-ulnar deviation rarely occurs in functional activities 1
- Maximum range of motion in radial-ulnar deviation occurs when the wrist is near the neutral flexion-extension position 1
Clinical Relevance
- Radial-sided wrist pain typically involves pathology affecting structures on the thumb side, including the scaphoid bone, radial styloid, and scapholunate ligament 2
- Ulnar-sided wrist pain involves structures on the little finger side, including the triangular fibrocartilage complex (TFCC) and ulnotriquetral ligament 3
- The radial side of the wrist carries approximately 80% of axial load, while the ulnar side carries 20% 4
Biomechanical Coupling
- During radial-ulnar deviation, there is accompanying flexion-extension movement that is linearly related to the primary motion 1
- The secondary flexion-extension range during radial-ulnar deviation is approximately 75% of the primary radial-ulnar deviation range 1
- Extension naturally couples with radial deviation, while flexion couples with ulnar deviation 1