Usefulness of perceived level of exertion in patients with chronic low back pain attending a physical training programme

Purpose. Firstly, to examine whether heart rate (HR) can be predicted based on the Borg-scale for perceived exertion in patients with chronic low back pain (CLBP) and secondly, to assess changes in HR, Borg-scores and workload to study the relevance of a stepwise increase of workload based on the Borg-score and HR. Methods. Ninety-nine patients with CLBP and a mean disability-score (Roland Morris Disability Questionnaire) of 13.8 (SD = 3.7) participated in a 10-week aerobic training programme (20 min, 3 times/week). HR, ratings of perceived exertion (RPE), and workload were monitored. Prior to treatment, patients completed questionnaires on pain, disability, and several psychological factors (catastrophizing, kinesiophobia, and depression). Results. The original Borg-equation (i.e. 'HR Borg x 10') appears accurate in predicting HR on a group-level. Pain-related and psychological factors were not significantly related to the accuracy of the Borg equation. Whereas mean workload increased significantly (from 93.8 (SD = 29.9) to 129.5 W (SD = 39.7), p <0.001) throughout the training programme, HR increased only slightly (from 130.2 (SD = 13.5) to 139.2 (SD = 13.9) bpm; p <0.001) and Borg-scores remained stable (from 13.2 (SD = 1.9) to 13.3 (SD = 1.8); p = 0.48). Conclusions. The capability of the Borg-scale to accurately predict HR appears moderate. However combined with measuring HR, it results in a relevant and efficient method for training CLBP patients in clinical practice.