RESUMO
This laboratory cross-sectional study aimed at explore the muscle response (MR) of the upper trapezius, infraspinatus, biceps brachii and extensor carpi radialis brevis (ECRB) during the radial nerve-biased upper limb neurodynamic test (RN-ULNT) in healthy participants. Myoelectric activity was stage-by-stage recorded during two sequencing variants of the RN-ULNT: S1, in which elbow extension was the last movement; and S2, in which wrist flexion was the last movement. Final elbow and wrist joint angle and sensory response (SR) in five zones (Z1-Z5) were also registered. MR was qualitatively categorized as 'absent' (No-MR), 'true' (TMR) or 'uneven' (UMR). In both sequences, significant increases in muscle activity occurred mostly during shoulder abduction and elbow extension (p ≤ 0.009). Also, elbow extension but not wrist flexion increased the activity of the ECRB muscle (p ≤ 0.009). S2 showed significantly higher upper trapezius (p = 0.04) and biceps brachii (p = 0.036) muscle activity during wrist flexion, and higher report of SR in Z1 and Z4 (p < 0.001) compared to S1. Only the ECRB muscle showed significant differences in the MR type between S1 and S2 (TMR, p = 0.016; UMR, = 0,012). Our results may be useful in the assessment of upper limb musculoskeletal disorders.
Assuntos
Nervo Radial , Extremidade Superior , Humanos , Nervo Radial/fisiologia , Estudos Transversais , Extremidade Superior/fisiologia , Punho , Músculo Esquelético/fisiologiaRESUMO
STUDY DESIGN: Diagnostic accuracy. INTRODUCTION: Upper limb neurodynamic test 1 (ULNT1) is used to evaluate the mechanical sensitivity especially in the peripheral nerves of the upper limbs. The reproduction of typical symptoms in the affected hand improves the estimation of the probability of carpal tunnel syndrome (CTS). However the test has not been evaluated sufficiently to determine its real usefulness. In the present study the diagnostic accuracy of ULNT1 as a clinical test for CTS was determined. METHODS: We used the ULNT1 as the index test and nerve conduction as the reference standard. 120 subjects, (240 hands), with a medical diagnosis of CTS were evaluated. The study population was a consecutive series of participants. Sensitivity, specificity, positive and negative predictive values, accuracy, and positive likelihood ratio were calculated. RESULTS: ULNT1 was found to have a sensitivity of 93 % and a specificity of 6.67 %. The positive likelihood ratio was 1.04 and the negative likelihood ratio was 1.00. The positive predictive value was 86.9 % and the negative predictive value was 12.5%. DISCUSSION: Acute or relatively mild CTS cases may not be accurately identified through nerve conduction tests. The findings of this study coincide with other studies in the finding that ULNT1 has a significant diagnostic and clinical screening value for CTS in people at-risk, or with upper limb symptoms. CONCLUSION(S): This research suggests the use of ULNT1 as a screening test for CTS, followed by tests that are more specific. LEVEL OF EVIDENCE: III-2.