[Lifting capacity with low back pain : Discrepancy between self-rated and real lifting capacity in patients with back pain and pain-free controls].

BACKGROUND: The fear-avoidance model implies that in situations with physical demands patients with back pain will overestimate the demand and underestimate their own capacities. PATIENTS AND METHODS: A total of 71 patients with back pain and 48 pain-free control subjects carried out a standardized lifting test with a preceding estimation of their lifting capacity. RESULTS: In both groups the self-estimation and real lifting capacity were in concordance for most group members with patients showing less disconcordance than controls. In the control group 35% of the subjects even underestimated their lifting capacity, which was the case in only 14% of the patients. Patients more frequently overestimated their capacity than pain-free controls (14% vs. 2%). Within the patients subgroups could be identified where patients in general either underestimated or overestimated their own capacity. A comparison between the groups demonstrated significant differences in pain intensity, fear avoidance beliefs and effort. CONCLUSION: As an explanation for these unexpected results it can be hypothesized that in cases of back pain, patients' attention is focused on pain-relevant issues which enables a more realistic estimation of their lifting capacity.