Effects of pulsed electromagnetic fields on mechanical allodynia after acute skeletal muscle contusion in rats / 中华物理医学与康复杂志

ABSTRACT

Objective To observe the effects of pulsed electromagnetic fields (PEMFs) on behavior and mechanical paw withdrawal thresholds (MPWTs) after acute skeletal muscle contusion (ASMC) in rats, and to in-vestigate the application of PEMFs in rats with ASMC during the early stage. Methods Forty-two Sprague-Dawley rats were randomly divided into a PEMF group (P group) , control group (C group) and blank control group ( BC group). ASMC models were set up in groups P and C, and no intervention was applied in the BC group. A PEMF was administered to animals in the P group immediately after the ASMC was inflicted. The behavior of the rats in each group was then observed. The MPWT of each rat was tested 2 days before and 0, 12, and 18 hours after the ASMC was inflicted). Results In the P and C groups, MPWT of the left hind paw at the 12th and 18th hour after ASMC was significantly lower than the baseline pain threshold 2 days before the ASMC. At 18 hours, the MPWT was signifi-cantly higher than at 12 hours in the P group. MPWT at 12 hours in the P group and at both 12 and 18 hours in the C group were significantly lower than in the BC group. MPWT in the P group at 18 hours was significantly higher than in the C group. Conclusions The behavior of rats treated with PEMF immediately after ASMC was improved, and their pain threshold was still elevated 18 hours later.