Validity of the Upper Limb Neurodynamic Test 1 for the diagnosis of Carpal Tunnel Syndrome. The role of structural differentiation

•Individuals with suspected CTS were invited to voluntarily participate in the study.•NCS were considered the Gold Standard for the diagnosis of CTS in this study.•ULNT1 was positive when patient's symptoms were reproduced and changed during SD.•The LRs suggested that the ULNT1 generates small shifts in post-test probability.•Due to imprecision in the CIs ULNT1 alone shouldn't be used to diagnose CTS.