Execution
- 1Have the patient lie supine with the shoulder girdle stabilised in depression.
- 2Medially rotate the shoulder, abducts it to about 40°, and extend it slightly.
- 3Extend the elbow while pronating the forearm.
- 4Flex the wrist and fingers with ulnar deviation to bias the radial nerve.
- 5Add contralateral cervical side flexion if required and compare symptom response with the opposite limb.
Positive outcome
Reproduction of the patient's familiar radial-nerve-type symptoms, especially lateral arm, dorsal forearm, or dorsal hand symptoms. A positive result is more meaningful when symptoms are modified by cervical sensitising movements.
Studies
| Study | Reliability | Sn | Sp | LR+ | LR− |
|---|---|---|---|---|---|
| Wainner et al. (2003) — see note | 0.83 | 72 | 33 | 1.07 | 0.85 |
| Petersen & Covill (2010) | ICC 0.75 right; ICC 0.81 left | NA | NA | NA | NA |
CommentThe radial-nerve-biased ULNT has limited standalone diagnostic value for cervical radiculopathy because specificity is low. It is more useful for comparing mechanosensitivity between sides and differentiating radial nerve bias from median or ulnar nerve presentations. Citation flag: Wainner 2003 specifically tested ULNT-A (median nerve = ULNT1); whether the same paper reports diagnostic accuracy for ULNT3 (radial bias) needs primary-source verification before relying on these values for teaching.
Low Clinical Value