Figure 3
From: Enhanced sensitivity to punctate painful stimuli in female patients with chronic low back pain
Incidence of the reported pain to pinprick stimuli on the back and palmar and dorsal aspects of the hand. Incidence of reported pain is shown as a function of the pinprick stimulus force A. at the back (triangles), B. hand palmar (circles), and C. the dorsum of the hand (circles). Filled symbols: patients with chronic low back pain (CLBP), open symbols: healthy controls (HC). Population threshold (force at which 50% of pinprick stimuli were reported to be painful): dotted line in A, B and D. Asterisks in A, B, C depict significant differences (P < 0.05) between groups in the incidence of reported pain.