Effect of magnetotherapeutic device on pain associated with neck and shoulder stiffness

To examine the effectiveness of a neck-type magnetotherapeutic device (MTD), we performed a study of neck and shoulder pain or stiffness measured with a visual analog scale (VAS) and objective parameters (thermography, deep body thermometry, and a muscle meter). There were 62 patients (29 men and 33 women; mean age, 34 y; range, 21 to 58 y) in the study. The patients were randomly assigned (double-blinded) to receive treatment with the MTD or non-MTD. The MTD (maximum magnetic flux density, 55 ± 5 mT; length, 500 mm; and diameter, 4.5 mm) was applied externally to the site of pain. The non- MTD (0 mT; 500 mm; and diameter, 4.5 mm) was applied as a sham control. All patients received treatment for 7 days. In MTD patients, significant pain relief was observed 3 hours after beginning treatment compared with before treatment. Skin surface and deep body temperatures were significantly increased from the baseline values in the MTD group but not in the non- MTD group. The average values of VAS improvement, skin temperature, and deep body temperature in the painful area were significantly greater, and the average value of muscle stiffness was significantly lower in the MTD group than in the non- MTD group 7 days after beginning treatment.