Muscle soreness is one of the most common complaints of all in sports. Pulsed electromagnetic field therapy (PEMF) is an effective form of treatment according to a study presented by Danish researchers at the 13th Congress of the European Federation of National Associations of Orthopaedics and Traumatology (EFORT) in Berlin.
Deceleration creates mini-tears in muscles
Delayed muscle soreness is the form of pain that usually does not set in until hours after certain sets of muscles are subject to great exertion. It is caused by micro-tears in sarcomeres, the smallest functional units of muscle tissue. The tears are caused by the deceleration of a movement. Inflammations develop in the tears. Together with water, they form oedemas and cause the muscle to swell up. If waste products from these tears are transported twelve to 24 hours later and hit nerve cells, this leads to typical stretching pain.
Magnetic pulse triggers regeneration
Studies show that many of the widespread countermeasures such as stretching before and after workouts have scarcely any effect. Well-intended massaging even delays the healing instead of speeding it up. Heat treatment, for its part, does deliver positive results for pain relief and recuperation of the muscle fibres. In this first double-blind randomised placebo-controlled study of its kind, Danish researchers showed that pulsed electromagnetic field therapy has the potential to become established as a therapy for muscle soreness of the type that occurs after marathons, for example.
Study involving marathon runners
A group of 133 athletes participating in four marathon races were selected for the study. After a completed race, they were each given a pulsed electromagnetic field therapy (PEMF) device to take home with them. The pulsed electromagnetic field signals two 2-msec burst of 27.12-MHz sinusoidal waves every second. The peak magnetic field was 0.05 Gauss (G), which induced an average electric field in the muscle of 10 mV/cm with an effect of 7.3 mW/cm3. All subjects were told to use the device 20 minutes four times a day and place the device on the most painful area of their quadriceps.
Evaluation during squats and running
What the subjects did not know was that every second device handed out was a placebo device with a deactivated electromagnetic field. The placebo group did not notice because the PEMF method is not accompanied by any sensation at all in the tissue. The researchers were thus able to determine the effectiveness of this application in comparison with the placebo group. This difference was checked three times a day during a 90° squat the subjects were supposed to perform and then graphically depict the intensity of their pain. In addition, the lengths of time they ran on days after the marathon were also recorded.
Faster healing of pain and longer runs
The therapy group with activated PEMF devices did in fact produce the better results. On the first and second day after the marathon, the intensity of pain for them was considerably lower than for the placebo group. The running times on the day after the marathon provided confirmation. With pulsed magnetic field therapy, the athletes managed to run an average of 61 minutes whereas those in the control group ran only 27 minutes, not even half as long.
