Afshin Karimzadeh - Assistant professor of Physical Medicine & Rehabilitation, Imam Hossein Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Mehrdad Taheri - Assistant professor of Anesthesiology and Pain Fellowship, Imam Hossein Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Masume Bayat - Assistant professor of Physical Medicine & Rehabilitation, Imam Hossein Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Andrew Beale - Ph.D. of Circadian Biology, London, United Kingdom
Hossein Ahmadi - Faculty of Medicine, Hormozgan University of Medical Sciences, Bandar Abbas, Iran

Background: Chronic low back pain (CLBP) is one of the major health problems and CLBP patients suffer from reduced quality of life and loss or limitation of employment.Objectives: This study was aimed at comparing pinch pressure pain sensibility of the skin of total low back area in patients with nonspecific low back pain.Methods: This observational, case-control study was conducted on patients who had suffered from chronic low back pain (LBP) with an intensity score of more than ۲۵ (using the visual analog scale, VAS; ۰–۱۰۰ mm) for at least constant three months between October ۲۰۱۲ and June ۲۰۱۳. By mechanical pinching the skin of the lower back area, skin hyperalgesia was assessed in ۱۹۳ patients. Following a double-blind design, skin hyperalgesia was also assessed for the skin of the control group (۱۰۸ people).Results: Signs of hyperalgesia in the upper lateral quadrant of the gluteal area, around the posterior part of the iliac crest, were found in both groups but the degree of hyperalgesia in chronic nonspecific LBP patients (with & without symptoms) was significantly higher (P<۰.۰۰۱).Conclusion: The results demonstrated that pressure-induced localized gluteal skinfold tenderness (hyperalgesia) is found in most patients with chronic low-back pain.

Chronic low back pain, Hyperalgesia, Pressure Algometry, Skin Sensibility, Referred Pain