Agreement with Microcurrent Conductance, Serum Myoglobin, and Diagnostic Ultrasound When Evaluating Delayed Onset Muscle Soreness

Purpose/Hypothesis: To determine if agreement exists between microcurrent conductance through the skin over an injury, myoglobin levels in the serum, and diagnostic ultrasound measurements of swelling. Number of Subjects: 140. Materials/Methods: Subject underwent microcurrent conductance, serum myoglobin, diagnostic ultrasound, and strength testing before and after delayed onset muscle soreness (DOMS) was induced. Non-control subjects were also given a therapy wrap, dry heat, moist heat, or cold, either applied immediately or delayed 24 hours. Results: After induction of DOMS, there was agreement between significant 37% decreases in microcurrent conductance, significant 37% serum myoglobin increases, and significant 20% increases in quadriceps size, measured by diagnostic ultrasound. When either dry heat or cold was applied immediately, changes in these measurements were insignificant and less than 10%. Agreement was weaker when treatment was delayed 24 hours. Also, cold packs showed less than a 5% decrease in microcurrent conductance for covered areas compared to a 22% decrease for uncovered areas around the knee with 24 hour delay. Moist heat packs showed an insignificant change overall, but a significant 11% decrease for the covered center of the quadriceps with immediate treatment. Strength decreased 25% after DOMS, and all immediate treatments, along with 24 hour delayed cold and moist heat showed significantly smaller decreases. Conclusions: Changes in microcurrent conductance through the skin over injured tissue appear to be indicative of initial injury and recovery, and also for detecting the specific area of the injury. Clinical Relevance: Microcurrent through the skin over injured tissue appears to be a promising objective measurement of tissue injury as well as recovery from injury.