Abstract
In order to examine the effectiveness of a north-south polarity exchangeable permanent magnet (PEPM) similar to non-polarity exchangeable permanent magnet (N-PEPM), we performed a pathophysiological study on frozen shoulder pain by assessment of subjective (Visual Analogue Scale) and objective symptoms (thermography, blood flow and deep body thermometer). Sixty-four patients (32 males and 32 females, average age 43.1, 22–69 years old) were studied. PEPM therapeutic device and N-PEPM therapeutic device were randomly assigned to the patients under a double blind test. PEPM (5 mm × 12 mm, 120 mT, rotation/2 seconds, PIP Fujimoto Co., Ltd., Osaka) was applied externally at the site of pain. N-PEPM (5 mm × 12 mm, 120 mT non-rotation) was also applied as control. All patients received the treatment for 2 days. Significance was determined with ANOVA. In the subjective and objective symptoms, both PEPM and N-PEPM were effective, respectively. The improvement in PEPM patients was significantly greater than in N-PEPM patients. In PEPM patients, significant pain relief was observed only 3 h after application. Moreover, skin temperature, blood flow and deep temperature increased significantly after 24 h compared to N-PEPM. Most of the patients with frozen shoulder pain had a chronic history of pain, and the surface temperature of the shoulder region was lower than that in healthy subjects. It has been reported that N-PEPM causes an increase in blood circulation by increasing the level of acetylcholine in the synaptic space of the cholinergic vasodilator nerve endings. Therefore, the significantly greater pain relief observed with PEPM as compared to N-PEMP in this study may primarily be due to deeper and more widespread muscle permeation.