Two to five points were chosen, the depth was similar at 10-20 mm however the gauge of the injection needle was larger as would be expected at 0.5 mm vs 0.18mm for the Acupuncture needles.
The outcome measure was the VAS applied immediately before and after the first treatment, before each subsequent treatment and and 2 and 4 weeks following treatment with each measure showing improvements for both types of treatment but a significant difference in favour of the Acupuncture group.
The authors suggest this may be due to different mechanisms of pain suppression, however given the common use of the needle in both cases there could well be some overlap. This could be further evidence to support the notion that its not what you inject but the physiological effects of the needle itself. The advantage of ‘dry’ needling perhaps being a better ability to control dose thereby reducing the risk of over-stimulating more sensitive patients?