Contributions of Basic, Preclinical and Clinical Research to the Application of Induced Electrical Currents in the Indications of Rehabilitation and Physical Medicine

Overview

The application of induced electric currents is increasingly used in contemporary rehabilitation and physical medicine. The induced electric currents are generated by a time-varying magnetic field and are apparently the only or at least a major biologically active factor in the action of low-frequency electromagnetic fields. In addition to the “classical” pulse magnetotherapy, which provides the smallest densities of induced electric currents (usually thousandths to hundredths of A/m2), so-called distance or non-contact electrotherapy is increasingly popular, but rather known under the names contactless electrotherapy, electrodeless therapy, inductively coupled electromagnetic field therapy, high-induction electromagnetic field therapy, etc., which typically operates at higher current densities of pulse-induced electrical currents in the order of tenths to A/m2. High-induction magnetic stimulation with perceptual and muscular motor effects, which provides current density of tens to hundreds of A/m2 in treated tissues, is also a significant development. In this work, we first investigated the effect of induced electric currents on sensory neurons responsible for the transmission of stimuli of various modalities, including those associated with nociception. In these cells, bradykinin modeled inflammation accompanied by increased calcium ion concentration in the intracellular space. We have demonstrated the influence of distance electrotherapy and high induction magnetic stimulation on the reduction of calcium concentration in the cell as well as on the slower onset and decrease of bradykinin-induced calcium wave. However, induced electrical current pulses produced by high induction magnetic stimulation increased spontaneous neuronal activity of primary afferent sensory cells without the presence of bradykinin inflammatory mediator. Further research was focused on the study of the behavior of endothelial cells, important in terms of angiogenesis, under the influence of induced electrical currents. Here, the effect of low-frequency pulse induced electric currents on the viability of these cells and their metabolic activity was demonstrated. On the other hand, pulse-induced currents did not affect mesenchymal stromal cells, but the effect of amplitude-modulated induced harmonic currents of kilohertz frequencies, where the migration capacity of these stem cells involved in regenerative processes, as well as their ability to produce matrix-metalloproteinases increased significantly. In the framework of the present publication, an animal study is also presented where high induction magnetic stimulation is applied to the sus scrofa on the chest area. Despite the massive muscle contraction of the breast muscles, no effect other than mild changes in HRV (heart rate variability) was found from ECG analysis. The effect of high induction magnetic stimulation on the elasticity of patellae ligamentum was studied in healthy subjects. Ultrasonic elastometry showed a reduction in the Yang modulus of elasticity of this ligament, suggesting an improvement in its elastic properties after application of high induction magnetic stimulation. The effect of high induction magnetic stimulation on pain was clinically studied in a group of patients with degenerative musculoskeletal disorders. Pain reduction in chronic patients of 1.6 degrees ten degrees was demonstrated.

Keywords:

heart rate variability