Pain assessment with different intensity scales in response to loading of joint structures

The purpose of the present study was to compare intensity levels assessed on Borg's Category Scale for Ratings of Perceived Pain (BRPP) (1982) (a verbal scale using adjectives and adverbs combined with the numbers 0-10), with assessments on the Visual Analogue Scale (VAS) (a 10 cm horizontal line). Eight healthy subjects volunteered in an experimental study, where pain was provoked by load on passive soft tissue elbow joint structures. Each subject participated 4 times on different occasions in the same experimental set-up, which was divided into six 2 min periods; 3 periods with load induced by applied external weights causing load moments of 3.4 Nm, 4.5 Nm and 6.8 Nm plus that induced by the weight of the lower arm and hand (average 2.9 Nm), followed by 3 periods without external weights. Each series consisted of 12 assessments given during the last 10 sec period of each minute on either the BRPP or the VAS. No significant difference was found between the first and second time a scale was used by the same subject, and none between the assessments on the VAS and the BRPP. Intensity levels of pain increased with load and time and decreased after reduction of the load moments. It is concluded that both scales can be used to reliably assess intensity levels of perceived pain elicited by loading joint structures. Intensity levels, as assessed on both scales, are associated with applied external load and time for exposure.