Intensity of chronic pain modifies postural control in low back patients

Objective Some recent studies have provided evidence that alteration in central motor control may have causative impact on the emergence and sustenance of chronic pain. We hypothesized that comparison of postural control between patients with high (HP) and low pain (LP) level would display intergroup differences in favour of the LP group lending support for the postulated relationship between altered cortical function and pain. Methods Motivated by this concept, we investigated postural control in 36 subjects with chronic low back pain (CLBP) stratified into two groups according to the reported rest pain intensity on a numerical rating scale: LP group (n = 16) and high pain (HP) group (n = 20). The pressure pain threshold (PPT) of selected muscles was assessed on the involved and uninvolved sides. Body balance was investigated on hard or soft surface using postural performance. Results As regards pain measurements, the PPT of muscles was lower in HP than in LP (P