Immediate Effects of Dry Needling, and Acupuncture at Distant Points in Chronic Neck Pain: Results of a Randomized, Double-blind, Sham-controlled Crossover Trial
Purpose of the study: Evaluate any immediate effects of two different modes of acupuncture compared to sham laser acupuncture on motion-related pain and cervical spine mobility in patients with chronic neck pain (>2 months) and limited cervical mobility. The two modes of acupuncture are non-local, non-segmental acupuncture (NLA) at distal points and local needling of myofascial trigger points (dry needling-DN).
1a. R- Was the assignment of patients to treatments randomised?
Yes. Thirty-six participants were randomized into six different groups with six different treatment sequences by rolling a dice. Treatment allocation was concealed by having an independent researcher roll the dice prior to the beginning of the trial. The participants were aware that one intervention would be a sham procedure.
Inclusion criteria: >2 months pain duration, myofascial pain syndrome or cervical irritation syndrome
Exclusion criteria: radicular symptoms, segmental instability, fracture, prior surgery, contraindications to acupuncture, drug treatment or PT or MT in the last 4 weeks
1b. R- Were the groups similar at the start of the trial?
The authors did not report baseline characteristics of each group other than the inclusion criteria. It is unclear if the groups were different at baseline. However, overall, the study included more females than males, 79.4% of the participants had myofascial pain syndrome. Twenty-nine point four percent (10 of 34 patients) had a history of a whiplash injury. The mean age and age range was given for the treatment group (51.9 years and 24-81 years) and the control group (45.8 years and 25-84 years). This was the only baseline information presented in the study. This study did not report if the differences presented between groups had any effect on the results.
2a. A – Aside from the allocated treatment, were groups treated equally?
Yes. Each participant had his/her own sequence of NLA, DN, and sham laser acupuncture. A second group, “norm group” consisted of 21 healthy and untreated patients to determine reliability of measurements. All participants were treated equally throughout the study.
2b. A – Were all patients who entered the trial accounted for? – and were they analysed in the groups to which they were randomised?
Two patients were excluded from the study for different reasons. One patient refused their first post-treatment assessment and excluded himself from the trial shortly after. The second patient did not adhere to the guidelines of the study. Several patients were included in analysis that should have been taken out. One patient received all treatments offered, but due to the absence of the independent investigator, no post-treatment measurements were taken for the DN intervention. In addition, three patients reported needle aversion side-effects and treatment had to be stopped. After a short rest break, the session resumed.
3. M – Were measures objective or were the patients and clinicians kept “blind” to which treatment was being received?
Throughout the study, participants were kept blinded; however they were aware that one intervention would be a sham procedure. Therapists were blinded to the inactivation of the sham laser instrument.
Outcome measures included motion related pain using the VAS, range of motion measurements (an average of flexion, extension, side bending R/L, rotation R/L), and assessment of change on a verbal rating scale (6 point scale)
Results: How large was the treatment effect?
A Kruskal-Wallis H-test was performed to determine that the sequence of therapies had no influence on the results (P=0.76).
Results of motion-related pain showed that using non-local points decreased pain levels by 11.2 mm (95% CI 5.7, 16.7; P=0.00006) which proved to be effective compared to sham treatment. DN was shown to be ineffective compared to sham in that it only reduced pain levels by 1.0 mm (95% CI -4.5, 6.5).
How precise was the estimate of the treatment effect?
The authors report that pre-treatment measures and the NLA intervention are associated with post-treatment motion related pain, however no information is given regarding how much variance, or the strength of the association.
ROM measures improved with both the DN group (1.7 degrees; 95% CI 0.2, 3.2; P=0.028) and the NLA group (1.9 degrees; 95% CI 0.3, 3.4; P=0.014). NLA resulted in significantly superior improvement to both sham and DN using the verbal change rating scale (1.7 points; 95% CI 1.0, 2.5 and 1.5 points; 95% CI 0.4, 2.6; P=0.0008 respectively). There was no difference between DN and sham. Analysis through non-parametric methods results were the same.
Discussion: Will the results help me in caring for my patient? (ExternalValidity/Applicability)
Several factors limit the external validity of the results of this study.
- Sample size: The sample size is small and likely not representative of patients that we typically treat. Patient were consecutively selected from one location (Department of Physical Medicine and Rehabilitation and the Interdisciplinary Pain Unit at the University of Munich)
- Participant exclusion: The study has strong exclusion criteria; however participants with needle aversion should have been excluded.
- Three participants needed a short break in their treatment due to these symptoms.
- Under reported results: The results reported are heavily based on author conclusion and lack of numbers, graphs, and figures to support these statements.
The purpose of this study was to examine immediate effects of NLA and DN. Because DN typically causes increased soreness for a few days following the procedure, it is not surprising that treatment effects were small. A limitation to this study is a lack of a mid-week evaluation to determine the effect of the treatment 2-3 days later. Physiotherapists would still consider 2-3 days a somewhat immediate effect, as our focus is generally more long term. Further research needs to be done in this area to determine the effectiveness of NLA and dry needling.
Reference: Irnich D. et al. Immediate effects of dry needling and acupuncture at distant points in chronic neck pain: Results of a randomized, double-blind, sham-controlled crossover trial. Pain.2002;99:83-89.