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.


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.


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.


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.

Clin Chiropr. (2008) 11(4):175-181.

Author information: Gemmel H, Allen A. Anglo-European College of Chiropractic, 13-15 Parkwood Road, Bournemouth, BH5 2DF, United Kingdom.

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