AUGUST 10, 2009
Reference: Hugh Gemmell; Anna Allen….Clinical Chiropractic 2009; 240: pp.1-7
Background: Trigger points are a common cause of severe and disabling pain in chiropractic practice. While trigger points may be found in any skeletal muscle the majority are found in the upper trapezius. Relatively few studies have investigated non-invasive treatments for upper trapezius trigger points. Common manual therapy treatments utilized for upper trapezius trigger points in chiropractic include manual pressure and myofascial release. The purpose of this study was to compare the effect of a single treatment of ischaemic compression and activator trigger point therapy on active upper trapezius trigger points.
Methods: Fifty-two subjects with active upper trapezius trigger points met the participation criteria and were randomised to an ischaemic compression or activator trigger point therapy group. The primary outcome measure was Patient Global Impression of Change. Secondary outcome measures were an 11-point numerical rating scale for change in pain, and change in pressure pain threshold using an algometer for trigger point sensitivity. While the treating clinician and subjects were not masked to treatment assignment, the examiner was blind to treatment assignment until data analyses were completed. An independent t-test was used to compare the groups at baseline on the continuous variables. The Mann—Whitney U-test was used to compare the groups at baseline on the non-continuous variables. Relative risk ratios of improvement for the primary and secondary outcome measures were calculated with 95% confidence intervals for clinical significance.
Results: Seventy volunteers were screened with 25 subjects randomised to the ischaemic compression group and 27 to the activator trigger point therapy group. There was no significant difference between the groups in any of the baseline variables. On the primary outcome measure both groups improved (78% of those in the activator group and 72% in the ischaemic compression group). Relative risk for improvement of 1.00 suggested that those treated with the Activator instrument were no more likely to improve than those treated with ischaemic compression (95% CI = 0.73—1.37). For the secondary outcome measure of pain reduction 41% of those treated with the Activator instrument improved compared to 36% of those in the ischaemic compression group. Those treated with the Activator instrument were 13% more likely to improve than those treated with ischaemic compression. However this relative risk of 1.13 in favour of the activator group was not significant (95% CI = 0.57— 2.26). For the secondary outcome of reduction in trigger point sensitivity 32% of those in the ischaemic compression group improved compared to 30% in the activator group. Those treated with ischaemic compression were 8% more likely to improve; however, the relative risk of 1.08 was not significant (95% CI = 0.48—2.44). As risk of improvement on the outcome measures between the groups was not significantly different, number needed to treat was not calculated.
Conclusion: Based on the primary outcome measure the results suggest that both ischaemic compression and activator trigger point therapy have an equal immediate clinically important effect on upper trapezius trigger point pain.