title: Improving the radial nerve neurodynamic test: An observation of tension of the radial, median and ulnar nerves during upper limb positioning.
abstract: The radial nerve neurodynamic test (ULNT2b), used to implicate symptoms arising from the radial nerve, is proposed to selectively increase strain of the nerve without increasing strain of adjacent tissue, though this has not been established. This study aimed to determine the upper limb position that results in: (1) the greatest tension of the radial nerve and (2) the greatest difference in tension between the radial nerve and the other two major nerves of the upper limb: median and ulnar. Tension (N) of the radial, median and ulnar nerves was measured simultaneously using three buckle force transducers during seven upper limb positions in the axilla of ten embalmed whole body human cadavers (n = 20 limbs). Repeated measures analysis of variance (ANOVA) with Bonferroni post-hoc tests determined differences in tension between nerves and between limb positions. A Composite position consisting of ULNT2b (scapular depression, shoulder internal rotation, elbow extension, forearm pronation, wrist flexion) with the addition of shoulder abduction 40° and extension 25°, wrist ulnar deviation and thumb flexion demonstrated significantly greater tension of the radial nerve than any other tested position (mean tension 11.32N; 95% CI 10.25, 12.29, p < 0.01), including ULNT2b (2.20N; 1.84, 2.57; p < 0.01). Additionally, the Composite position demonstrated the greatest difference in tension between the radial and median (mean difference 4.88N; 95% CI 3.16, 6.61; p < 0.01) and radial and ulnar nerves (9.26N, 7.54, 10.99; p < 0.01). This position constitutes a biomechanically plausible test to detect neuropathic pain related to the radial nerve.
authors.affiliation: Discipline of Physiotherapy, School of Health Sciences, Faculty of Health and Medicine, The University of Newcastle, Callaghan, NSW 2308, Australia.
authors.forename: Joshua J
authors.initials: JJ
authors.lastname: Manvell
authors.affiliation: Discipline of Physiotherapy, School of Health Sciences, Faculty of Health and Medicine, The University of Newcastle, Callaghan, NSW 2308, Australia.
authors.forename: Nicole
authors.initials: N
authors.lastname: Manvell
authors.affiliation: Discipline of Physiotherapy, School of Health Sciences, Faculty of Health and Medicine, The University of Newcastle, Callaghan, NSW 2308, Australia. Electronic address: Suzanne.Snodgrass@newcastle.edu.au.
authors.forename: Suzanne J
authors.initials: SJ
authors.lastname: Snodgrass
authors.affiliation: Discipline of Physiotherapy, School of Health Sciences, Faculty of Health and Medicine, The University of Newcastle, Callaghan, NSW 2308, Australia.
authors.forename: Susan A
authors.initials: SA
authors.lastname: Reid
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002102:Cadaver; D004551:Elbow Joint / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008475:Median Nerve / Q000502:physiology*; D015588:Observer Variation; D011403:Pronation / Q000502:physiology; D011826:Radial Nerve / Q000502:physiology*; D016059:Range of Motion, Articular / Q000502:physiology*; D012399:Rotation; D012785:Shoulder Joint / Q000502:physiology; D013314:Stress, Mechanical; D013484:Supination / Q000502:physiology; D016683:Supine Position; D014459:Ulnar Nerve / Q000502:physiology*; D034941:Upper Extremity / Q000294:innervation*; D014955:Wrist Joint / Q000502:physiology
keywords: Brachial plexus; Mechanical stress; Peripheral nervous system diseases