ELECTROMAGNETIC INDUCTION FOR TREATMENT OF UNSPECIFIC BACK PAIN: A PROSPECTIVE RANDOMIZED SHAM-CONTROLLED CLINICAL TRIAL

OBJECTIVE: To evaluate the effects of high-energy pulsed electromagnetic fields on unspecific back pain. METHODS: A prospective, randomized, sham-controlled clinical trial with repeated measurements was performed. The study included 5 visits (V(0) to V(4)) with 3 interventions during V(1), V(2) and V(3). Sixty-one patients aged between 18 and 80 years with unspecific back pain (acute inflammatory diseases and specific causes were reasons for exclusion) were included. The treatment group (n = 31) received 1–2 pulses/s, with an intensity of 50 mT, and an electric field strength of at least 20 V/m on 3 consecutive weekdays for 10 min each time. The control group (n = 30) received a comparable sham therapy. Pain intensity (visual analogue scale), local oxyhaemoglobin saturation, heart rate, blood pressure, and perfusion index were evaluated before ((b)) and after ((a)) V(1) and V(3) interventions. Change in visual analogue scale for V(1) (Change(V1a-b)) and V(3) (Change(V3a-b)), and ChangeData between V(3a) and V(1b) (Change(V3a–V1b)) for the remaining data were calculated (results were mean (standard deviation) (95% confidence interval; 95% CI)). RESULTS: Concerning the visual analogue scale: (i) compared with the control group, the treatment group had higher Change(V1a–b) (–1.25 (1.76) (95% CI –1.91 to –0.59) vs –2.69 (1.74) (95% CI –3.33 to –2.06), respectively), and comparable -Change(V3a–b) (–0.86 (1.34) (95% CI –1.36 to –0.36) vs –1.37 (1.03) (95% CI –1.75 to 0.99), respectively); and (ii) there was a significant marked decrease in Change(V3a–1b) in the treatment group compared with the control group (–5.15 (1.56) (95% CI –5.72 to –4.57) vs –2.58 (1.68) (95% CI –3.21 to –1.96), p = 0.001, respectively). There was no significant Change(V3a–V1b) in local oxyhaemoglobin saturation, heart rate, blood pressure or perfusion index between the 2 groups and for the same group (before vs after). CONCLUSION: Non-thermal, non-invasive electromagnetic induction therapy had a significant and rapid influence on unspecific back pain in the treatment group. LAY ABSTRACT Back pain is a health disorder of outstanding epidemiological, medical, and health economic importance. In the case of unspecific back pain, there is no clear specific cause. Electrotherapy is a physical therapy procedure using electric current for therapeutic purposes. Electromagnetic induction can influence many biological processes that are important for therapeutic interventions. A relatively new method is the use of non-invasive, very short, high-energy pulsed electromagnetic fields. Based on the literature, observations, and guidelines available up to February 2023, therapeutically successful use of electromagnetic induction appears possible, particularly in the case of high-energy pulsed electromagnetic fields. Pulsed electromagnetic fields with high-energy pulsed electromagnetic fields are therefore the logical therapeutic extension of high-energy pulsed electromagnetic fields. This study was designed to test the theory that high-ener-gy pulsed electromagnetic fields can reduce unspecific back-pain. The application of electromagnetic induction, short high-frequency and high-energy, but non-thermal, electromagnetic pulses with a magnetic flux density of approximately 50–100 mT was found to reduce unspecific back-pain in the treatment area of the treatment group.