A prospective, randomized, double blind, placebo controlled clinical trial assessing the effects of applying a force to the C5 facet joints by a mechanically assisted instrument (MAI) on referred pain to the shoulder.

Abstract

Background: Manipulating the C5 facet joints is a popular chiropractic treatment for referred shoulder pain, however there are no clinical trials evaluating its efficacy.

Aim: To determine the effects of applying a force to the C5 facet joints by a mechanically assisted instrument (MAI) in patients presenting with referred shoulder pain.

Methods: This was a prospective, randomized, double blind, placebo controlled trial to assess the effects of applying a force to the C5 facet joints by a MAI to patients with referred shoulder pain. For this trial; the treatment cohort had the MAI set at the maximum setting (5 rings) to transmit a force into the spine; the placebo cohort had the MAI turned off (0 ring). Primary outcome measures were frequency and severity of extreme shoulder pain obtained via a patient reported questionnaire; secondary outcome measures were patient ranked pain and functional outcomes as well as examiner assessed range of motion and strength. Assessment procedures were completed at 24 weeks post treatment and data were analysed with an intent to treat protocol.

Results: One hundred and twenty-five patients were recruited for this trial, sixty five were in the treatment cohort and sixty in the placebo cohort.

There was a reduction in the frequency but not severity of extreme shoulder pain in the treatment cohort, with average ranking reducing from weekly to monthly (p<0.05). Patients treated with the MAI had 10 N (p=0.04) better internal rotation strength after 6 months post-treatment. There were, however, no differences with any other outcome measures between the two cohorts at the 24 week study period.

Conclusion: The major effect of a MAI over placebo applied to the C5 facet joints two times per week for six weeks, then once a week for three weeks in patients who presented with referred shoulder pain was improved shoulder strength in internal rotation at 24 weeks (p=0.04).