Measurement Properties and Muscular Demands of a Pneumatic Pain Meter: A Laboratory-Controlled Study

We determined muscular demand, within-day instrument reliability, and criterion-concurrent validity of a pneumatic pain meter device. Fifty healthy adults (22 males, 28 females; age 23 ± 6 years) completed 30 block-randomized trials meeting target levels between 10 and 100 with concurrent measures of electromyography. Experimental pain was induced over the low back and pain ratings were taken on the device as well as a 100 mm visual analog scale before induction and at 10, 20 and 30 min. Electromyography levels significantly increased from target levels 0 to 100 (p <.001), and no significant fatigue, identified as a shift in median power frequency, was identified (p =.095). Within-day reliability was excellent: ICC_3,1 = 0.998 (95% confidence interval 0.997–0.998). A Bland-Altman analysis showed that 95% of the differences between the pain meter and visual analog scale fall within limits of agreement of +13.27 and −18.62. Future work should confirm measurement metrics in special populations and extended periods of time.