Dry Needling in Patients With Chronic Neck Pain

The investigators study the efficacy of a combination of dry needling plus manual therapy against sham dry needling plus manual therapy in the treatment of chronic neck pain. The investigators identify the most active trigger point in the upper trapezius and levator scapulae and administer two treatments, with an interval of 7 days, with a follow up 30 days after the first intervention. The primary outcome is the Visual Analogue Scale of Pain. Secondary outcomes ar pressure pain threshold, Neck Disability Index (NDI) questionnaire and range of motion.

A prospective single-blind randomized controlled trial, designed to assess the efficacy of dry needling in the treatment of chronic neck pain. The treatment regimes simulate the standard physiotherapy administered in real clinical settings. Patients in the intervention group receive a combination of manual therapy and dry needling (40mmx0,32 guided needles). There are two control groups. In the first one, patients receive a combination of manual therapy and sham dry needling. In the second control group, patients receive no treatment in order to assess the natural history of the disease.

Patients receive two treatment sessions with an interval of 7 days and are followed up after 30 days. The primary outcome is subjective pain assessed with a Visual Analogue Scale (VAS). Secondary outcomes are pressure pain threshold (assessed with a manual algometer), neck range of motion (assessed with a goniometer) and the Neck Disability Index (a standardized questionnaire). Measurements are taken pre and post-test after the first and the second treatment sessions, plus once more at the follow-up, except for the Neck Disability Index (only at the beginning and after the second treatment). In the non-treated group, patients were measured at the same time intervals.

The sample size was calculated to detect a VAS difference of 2 points, the minimally clinically important difference established in the literature. Then it was doubled in order to avoid possible dropouts. The trial takes place in a private practice in Madrid (Physios, c/Valverde 26). Patients are randomized by a computer program.

Patients are explored for active trigger points in the upper trapezius and the levator scapulae. They should meet the criteria of identification established by Travell \& Simons in their Trigger point manual. The investigators also seek for trigger points following Travell \& Simons' pain maps for these two muscles, where they identify five trigger point areas. The investigators select the most active, taking pressure pain threshold measurements of all the active trigger point, normalizing the values according to normal thresholds for each of the five areas in the two muscles. The normal thresholds were assessed in a pilot study with healthy patients. The investigators administer either dry or sham dry needling to the most active (the one with the lowest pain threshold) throughout the trial.

Dry needling is applied following Hong's technique with 40mmx0,32 guided needles, by a physiotherapist with 4 years of experience in the technique.

Eligibility Criteria:
Inclusion criteria

* Neck pain for at least three months (or more)
* An active trigger point in either the upper trapezius or the levator scapulae

Exclusion criteria

* Treatment for neck pain within the previous six months
* Neck Whiplash
* Fibromyalgia
* Infection in the area under treatment
* Pharmacological treatment with anti-coagulants
* Fear to needles
* Degenerative conditions
* Pregnancy