Twenty-three subjects with sensitive trigger points over the trapezius.
Placebo iontophoresis treatment without current or lidocaine, control treatment using distilled water and normal current dose, medicated treatment using 1% lidocaine and normal current dose.
Main Outcome Measure:
Trigger-point pressure threshold assessed with an algometer.
ANOVA revealed a significant difference among treatments (F2,40 = 7.38, P < .01). Post hoc comparisons revealed a significant difference in pressure threshold between the lidocaine treatment and the control (P = .01) and placebo (P = .001) treatments. Effect sizes of .28 and .39, respectively, were found for these comparisons.
Although the data revealed significant differences between treatments, the small effect sizes and magnitude of the pressure-sensitivity deviation scores suggest that iontophoresis with 1% lidocaine is ineffective in treating trigger points.
Evans and Denegar are with the Center for Orthopaedic and Sports Medicine and the Dept of Kinesiology, Athletic Training Research Laboratory, at The Pennsylvania State University, University Park, PA 16802. Kunkle, Zinz, and Walter are with the College of Health and Human Services at Slippery Rock University, Slippery Rock, PA 16057.