Ratings of perceived exertion in braille: validity and reliability in production mode

Objectives-(a) To assess the validity and reliability of producing and repr oducing a given exercise intensity during cycle ergometry using a braille v ersion of Borg's standard 6-20 rating of perceived exertion (RPE) scale, an d (b) to determine whether the exercise responses of blind participants, at a given produced RPE, were similar to those reported in recognised guideli nes for sighted subjects. Methods Ten healthy registered blind volunteer participants (four women, si x men; mean (SD) age 23.2 (9.0) years) performed an initial graded exercise cycle test to determine maximal heart rate (HRMAX) and maximal oxygen upta ke (V-O2MAX). Three trials of three exercise bouts at RPEs 9, 11, and 13 we re then performed in random order on three separate days of the same week, with expired air and heart rate measured continuously. Each exercise bout w as followed by 10 minutes of rest. The validity of the scale as a means of producing different exercise intensities was assessed using a two factor (R PE x trial) repeated measures analysis of variance. Intertrial reliability was assessed using intraclass correlation coefficients (ICC) and the bias 95% Limits of agreement (95%LoA) procedure. Results-Participants reported no difficulty in using the braille RPE scale. When asked to produce exercise intensities equating to RPE 9, 11, and 13, they elicited mean %V-O2MAX values of 47%, 53%, and 63% respectively. Analy sis of variance showed no significant differences in either %HRMAX or %V-O2 MAX between trials at each of the three RPEs, but there was a significant d ifference (p<0.001) in both %HRMAX and %V-O2MAX between the three RPE level s. All pairwise comparisons of the three different RPEs were significantly different (p<0.016). The ICC between the second and third trial for %HRMAX was significant (p <0.05) for all three RPEs. Similarly for %V-O2MAX, the I CC was significant for RPE 9 and 11 but not 13. The 95%LoA decreased for bo th %HRMAX and %V-O2MAX With each successive trial. Conclusions-Blind participants were successful in using a braille RPE scale to differentiate exercise intensity on a cycle ergometer. In every trial a t RPE 13, all participants achieved %HRMAX and %V-O2MAX levels, which fell within the recommended range for developing cardio respiratory fitness. Usi ng %HRMAX as a judge of intertrial reliability, the participants were able to repeat similar exercise intensities after two trials at each of the thre e RPEs (9, 11,13). The same was true for RPE 9 and Il,when %V-O2MAX was use d as a judge, but further trials were required to achieve similar reliabili ty at RPE 13. A braille RPE scale can be used by healthy blind people durin g cycle ergometry, with similar effect to the visual analogue scale recomme nded for use in healthy sighted people.