Reliability and minimal detectable change of a modified passive neck flexion test in patients with chronic nonspecific neck pain and asymptomatic subjects.
The Passive Neck Flexion Test (PNFT) can diagnose meningitis and potential spinal disorders. Little evidence is available concerning the use of a modified version of the PNFT (mPNFT) in patients with chronic nonspecific neck pain (CNSNP).



To assess the reliability of the mPNFT in subjects with and without CNSNP. The secondary objective was to assess the differences in the symptoms provoked by the mPNFT between these two populations.



We used repeated measures concordance design for the main objective and cross-sectional design for the secondary objective.



A total of 30 asymptomatic subjects and 34 patients with CNSNP were recruited. The following measures were recorded: the range of motion at the onset of symptoms (OS-mPNFT), the range of motion at the submaximal pain (SP-mPNFT), and evoked pain intensity on the mPNFT (VAS-mPNFT).



Good to excellent reliability was observed for OS-mPNFT and SP-mPNFT in the asymptomatic group (intra-examiner reliability: 0.95-0.97; inter-examiner reliability: 0.86-0.90; intra-examiner test-retest reliability: 0.84-0.87). In the CNSNP group, a good to excellent reliability was obtained for the OS-mPNFT (intra-examiner reliability: 0.89-0.96; inter-examiner reliability: 0.83-0.86; intra-examiner test-retest reliability: 0.83-0.85) and the SP-PNFT (intra-examiner reliability: 0.94-0.98; inter-examiner reliability: 0.80-0.82; intra-examiner test-retest reliability: 0.88-0.91). The CNSNP group showed statistically significant differences in OS-mPNFT (t = 4.92; P < 0.001), SP-mPNFT (t = 2.79; P = 0.007) and in VAS-mPNFT (t = -10.39; P < 0.001) versus the asymptomatic group.



The mPNFT is a reliable tool regardless of the examiner and the time factor. Patients with CNSNP have a decrease range of motion and more pain than asymptomatic subjects in the mPNFT. This exceeds the minimal detectable changes for OS-mPNFT and VAS-mPNFT.
Department of Physiotherapy, Faculty of Health Science, Centro Superior de Estudios Universitarios La Salle, Universidad Autónoma de Madrid, Aravaca, Madrid, Spain; Motion in Brains Research Group, Centro Superior de Estudios Universitarios La Salle, Universidad Autónoma de Madrid, Aravaca, Madrid, Spain; Institute of Neuroscience and Craniofacial Pain (INDCRAN), Madrid, Spain; Hospital La Paz Institute for Health Research, IdiPAZ, Madrid, Spain; Faculty of Health Science, Escuela Internacional de Doctorado, Universidad Rey Juan Carlos, Alcorcón, Madrid, Spain. Electronic address: ibai.uralde@gmail.com.
Ibai
I
López-de-Uralde-Villanueva
Department of Physiotherapy, Faculty of Health Science, Centro Superior de Estudios Universitarios La Salle, Universidad Autónoma de Madrid, Aravaca, Madrid, Spain.
Mario
M
Acuyo-Osorio
Motion in Brains Research Group, Centro Superior de Estudios Universitarios La Salle, Universidad Autónoma de Madrid, Aravaca, Madrid, Spain.
María
M
Prieto-Aldana
Department of Physiotherapy, Faculty of Health Science, Centro Superior de Estudios Universitarios La Salle, Universidad Autónoma de Madrid, Aravaca, Madrid, Spain; Motion in Brains Research Group, Centro Superior de Estudios Universitarios La Salle, Universidad Autónoma de Madrid, Aravaca, Madrid, Spain; Institute of Neuroscience and Craniofacial Pain (INDCRAN), Madrid, Spain; Hospital La Paz Institute for Health Research, IdiPAZ, Madrid, Spain.
Roy
R
La Touche
D000328:Adult; D059350:Chronic Pain / Q000175:diagnosis* / Q000503:physiopathology*; D003430:Cross-Sectional Studies; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D008875:Middle Aged; D019547:Neck Pain / Q000175:diagnosis* / Q000503:physiopathology*; D016059:Range of Motion, Articular / Q000502:physiology*; D015203:Reproducibility of Results; D013030:Spain
Neck pain; Neural provocation test; Repeatability; Smallest detectable change