Attention-demand effects on respiration in chronic low back pain patients.

Increasing attention is being drawn towards the involvement of systems other than the musculoskeletal one in the presence of low back pain (LBP). Recent evidence suggests both cognitive and respiratory functions to be affected in LBP patients. The aim of this study was to compare the effect of performance of a cognitive task on the respiratory function in LBP patients with that in control participants. Capnography and spirometry parameters of 48 participants (24 in each group) were assessed under 3 cognitive loading conditions (no, easy and difficult cognitive task). The results showed that in both groups the respiratory function was significantly affected by the introduction of the cognitive task (p < 0.05) and in the same manner (p > 0.05). Capnography and spirometry variables alterations were significantly correlated in the no-LBP group (p < 0.05) but there was no significant relationship between respiratory parameters and capnography and disability indices in the LBP group (p > 0.05). The findings of the current study suggest that while performing a cognitive task affects respiratory function, the possible differences of LBP patients and control participants may not be elicited under simple non-physically demanding postural conditions.