This study’s goal was to examine the effects of thermal agents on electrical sensory threshold and current tolerance when applied immediately before neuromuscular electrical stimulation. In this single-blind and cross-over trial, electrical sensory threshold and current tolerance of 24 healthy volunteers were evaluated by using biphasic symmetrical pulses (240 μsec, 50 pps), prior to and following thermal agent (cold pack, hot pack and ultrasound) applications. Electrical sensory threshold increased after cold-pack, and current tolerance reduced after hot-pack applications (p< 0.05). Inter-agent comparisons of pre and post-application differences of the investigated parameters showed that the most obvious effects were induced by application of hot pack.
The study found that hot pack application before neuromuscular electrical stimulation (NMES) could reduce current tolerance and limit to reach the desired current intensity for strengthening the electrically induced contractions. Results are thought to be of value for physiotherapists, who apply thermal agents and NMES consecutively, in their treatment programs.