The Effects of Low-Dosed and High-Dosed Low-Frequency Electromagnetic Fields on Microcirculation and Skin Temperature in Healthy Subjects

Abstract

The purpose of this randomized double-blind cross-over study was to investigate whether a low-dosed pulsed low-frequency magnetic field or a high-dosed pulsed low-frequency magnetic field improves the cutaneous microcirculation and alters the temperature of the foot. Twelve healthy subjects (five women, seven men) aged on average 25.8 years participated in the trial. Based on a randomization list, one of the following three interventions was applied for 30 min through a cushion placed below the non-dominant foot: either a pulsed low-dosed magnetic field (100 uT, basic frequency 30 Hz with a frequency modulation) or a pulsed high-dosed magnetic field (8.4 mT, 10 Hz), or sham treatment. The individual treatment sessions were applied in intervals of one week, at the same time of the day. Cutaneous microcirculation (laser Doppler flowmetry) and temperature (infra-red thermovision) were measured in the dorsum of the foot and the great toe every 5 min during the intervention, and 5 and 10 min post-intervention. With both pulsed low-dosed magnetic field and pulsed high-dosed magnetic field, just as with the sham treatment, a minor drop in temperature and decrease in microcirculation took place. A two-way repeated-measures analysis of variance revealed no significant difference between the interventions for any parameter. It was concluded that a local application of a pulsed low-frequency magnetic field to the foot did not enhance temperature or cutaneous microcirculation in healthy subjects.

The cardiovascular response to an acute 1800-μT, 60-Hz magnetic field exposure in humans

“…Although core body temperature may have decreased over the full duration of the experimental sessions, we are confident that the time that elapsed from the subjects arrival at the laboratory to the commencement of the experiment (approximately 30 min for paper work completion and EEG/ECG set up) was sufficient for subjects to adjust to a resting state suitable for baseline cardiovascular parameter measurements to be made. This period was selected based on the acclimatization period used in the laser Doppler investigation of the microcirculatory response to low-frequency MF in Schuhfried et al (2005) and is supported by studies of HR and skin temperature demonstrating a return to baseline within this timeframe (Martinmaki and Rusko 2008;Ryan et al 2009;Thoden et al 1994;McInnis et al 2006). The absence of a session by block interaction offers strong support for the observed findings of decreasing skin blood perfusion values over time while inactive.…”

“…For this reason, some researchers have advocated using laser Doppler imaging which utilizes a weighted average from a much larger surface collection area. Although the method chosen to measure the microcirculation may have its limitations, one of the aims of this study was to determine whether the laser Doppler measurement technique was adapted for detecting overall changes in skin blood perfusion, and the choice of this technique was based on previously published laser Doppler microcirculation studies (Schuhfried et al 2005;Mayrovitz et al 2001;McKay et al 2009). …”

Application of thermovision for estimation of the optimal and safe parameters of the whole body cryotherapy

“…The superficial body temperature distribution is not even; the highest one is on the trunk, the lower in the extremities [23]. It may be influenced by pathological changes [4,17], as well as by external stimuli [24,25]. Due to these poikilothermic and behavioral features, the human body may be exposed safely to extremely low temperatures [2,4,[26][27][28][29].…”

Elektromagnetische Felder bei Patienten mit chronischen Rückenschmerzen(low-back pain): Eine doppelblinde randomisierte Duo-Center-Studie

“…Deren therapeutische Erfolge gelten -bis auf einige Ausnahmen [1,6,11,[13][14][15][16][17]20,21,22,24,28,29,31] jedoch aufgrund nicht evidenzbasierender Untersuchungen, vor allem aber wegen der vielen, auf ungeprüfte Hypothesen aufgesetzten Heilversprechen, insbesondere zur Mikrozirkulation, als ungesichert [2,10,18,25].…”