Repetition-induced activity-related summation of pain in patients with fibromyalgia.

This study compared individuals with fibromyalgia (FM) and individuals with chronic low back pain (CLBP) on repetition-induced summation of activity-related pain (RISP). Fear of movement, pain catastrophizing and depression were examined as potential mediators of group differences. The sample consisted of 50 women with FM and 50 women with CLBP who were matched on age, pain severity and pain duration.