ABSTRACT
Fibromyalgia is characterized by diffuse pain, the origin of which remains obscure. This study explored a phenomenon labeled Diffuse Muscle Coactivation (DMC) as a possible source of pain in fibromyalgia. DMC is defined as an increase from resting levels (tonus) in the electrical activity of any muscle during a movement which does not involve that muscle and is not part of the agonist-antagonist unit. When compared to controls this activity in persons with fibromyalgia was 1.75 times more prevalent and demonstrated significantly higher peak amplitudes. Possible neurological mechanisms are discussed.
Subject(s)
Electromyography , Fibromyalgia/complications , Muscle Contraction/physiology , Neurotransmitter Agents/analysis , Pain/etiology , Pain/physiopathology , Adult , Aged , Analysis of Variance , Biomarkers , Case-Control Studies , Confidence Intervals , Female , Fibromyalgia/physiopathology , Humans , Male , Middle Aged , Pain Measurement , Prospective Studies , Reference Values , Sensitivity and Specificity , Severity of Illness IndexABSTRACT
This study examined the electrical characteristics (Root Mean Square -- RMS and median frequency) of Diffuse Muscular Coactivation (DMC) associated with the tender points of fibromyalgia. DMC is defined as an increase from resting levels (tonus) in the electrical activity of any muscle during a movement which does not involve that muscle and is not part of the agonist -- antagonist unit. The results show an increase in RMS in fibromyalgia sufferers as compared to controls. Coactivation was stronger proximal to the neck and decreased in intensity as the area recorded moved distally. Median frequency changed over time but not significantly between groups. Possible neurological mechanisms are discussed.
