Figure 5:

Percent pain reduction 60-120 minutes after infusion as a function of mechanical pain threshold (MPT) and heat pain threshold (HPT), as tested on the most painful foot prior to infusion. Blue circle indicates placebo session; red square indicates lidocaine session. Two participants could not tolerate heat pain threshold probe on skin during testing. MPT regression line information: (n = 31): Placebo (blue): r = −.276, p = .133; Lidocaine (red): r = −.156, p = .401; difference between correlation coefficients p = .64. HPT regression line information (n = 29): Placebo (blue): r = −.062, p = .748; Lidocaine (red): r = .145, p = .454; difference between correlation coefficients p = .45.