Trapezius pain: a trial detects no difference between two durations of magnetic stimulation

Two durations compared, with the same stretching exercises

This single-center trial involved adults aged 18 to 55 with myofascial pain syndrome of the upper trapezius lasting at least three months. Their baseline pain was at least 4 points on a visual analog scale.

Participants were randomly assigned to two groups of 33 people. They received repetitive peripheral magnetic stimulation for 10 or 15 minutes, once a week for four weeks. Both groups also performed standardized stretching exercises.

The assessor, who was unaware of participants’ group assignments, measured pain, pressure pain threshold and neck-related disability. Assessments took place at baseline, at two weeks and at four weeks.

Improvement in both groups, with no advantage detected

At four weeks, the mean reductions in pain reported in the two groups were 4.87 and 5.02 points from baseline. Pressure pain threshold and neck-related disability also improved.

The adjusted between-group difference in pain was −0.27 points, with a 95% confidence interval ranging from −0.95 to 0.40. No statistically significant difference was detected for any of the three outcomes studied.

This does not demonstrate that the two durations are equivalent. In this sample and over this period, the researchers simply did not find evidence of an advantage of one over the other.

What this trial cannot establish

The comparison provides information about session duration, not about the effectiveness of stimulation compared with a placebo or stretching alone. Since all participants received both interventions, their improvement cannot be attributed solely to the device.

Follow-up ended at four weeks: whether the results persist remains unknown. These observations concern a specific pain syndrome and do not automatically apply to all neck pain.

The abstract consulted does not detail adverse effects. It therefore does not support conclusions about the device’s safety or turning these findings into a recommendation for use.

What we can take away

This trial shows no detectable advantage of 15-minute sessions over 10-minute sessions at four weeks. It demonstrates neither their equivalence nor the effectiveness of magnetic stimulation itself.