Effects of Dry Needling on Biomechanical Properties of the Myofascial Trigger Points Measured by Myotonometry: A Randomized Controlled Trial

Effects of transcutaneous radiofrequency diathermy versus ultrasound on latent myofascial trigger points in the upper trapezius: A randomized crossover trial

BACKGROUND

Currently, the use of radiofrequency diathermy for the treatment of neck pain is booming.

OBJECTIVE

This study aimed to evaluate the clinical efficacy of Digital Capacitive Diathermy (DCD®) on stiffness, pain, cervical range of motion, and cervical disability and to compare it with ultrasound (US) in patients with latent myofascial trigger point (MTrP) in the upper trapezius.

METHODS

Nineteen participants with latent MTrPs in the upper trapezius were included in the assessor-masked, randomized, clinical crossover trial. Subjects were exposed to both interventions: US and DCD® and treatment effectiveness was measured by myotonometric variables, pressure pain threshold (PPT), visual analog scale (VAS), cervical side-bending flexion ranges, and the neck disability index scale (NDI).

RESULTS

There were no significant differences between US and DCD® interventions regarding changes in outcome measures. The US group achieved a statistically significant difference of 2.16 to 1.13 points (p= 0.005; r= 0.646) for the VAS. The DCD® intervention showed a statistically significant improvement of 1.11 points for the NDI at 1-week following intervention (95% CI 0.14-2.07; p= 0.27; d= 0.217).

CONCLUSION

Our findings suggest that DCD® and US can both be considered effective modalities for the treatment of latent MTrPs, having a longer duration of action with DCD® therapy.

Dry Needling Produces Mild Injuries Irrespective to Muscle Stiffness and Tension in Ex Vivo Mice Muscles

Numerous studies have suggested that the myofascial trigger points are responsible for most of the myofascial pain syndrome, so it seems reasonable that its destruction is a good therapeutic solution. The effectiveness of dry needling (DN) has been confirmed in muscles with myofascial trigger points, hypertonicity, and spasticity. The objective of this study is to analyze the need of repetitive punctures on muscles in different situations. The levator auris longus (LAL) muscle and gastrocnemius muscle from adult male Swiss mice were dissected and maintained alive, while being submerged in an oxygenated Ringer’s solution. DN was evaluated under four animal models, mimicking the human condition: normal healthy muscles, muscle fibers with contraction knots, muscles submerged in a depolarizing Ringer solution (KCl-CaCl2), and muscles submerged in Ringer solution with formalin. Thereafter, samples were evaluated with optical microscopy (LAL) and scanning electron microscopy (gastrocnemius). Healthy muscles allowed the penetration of needles between fibers with minimal injuries. In muscles with contraction knots, the needle separated many muscle fibers, and several others were injured, while blood vessels and intramuscular nerves were mostly not injured. Muscles submerged in a depolarizing solution inducing sustained contraction showed more injured muscular fibers and several muscle fibers separated by the needle. Finally, the muscles submerged in Ringer solution with formalin showed a few number of injured muscular fibers and abundant muscle fibers separated by the needle. Scanning electron microscopy images confirm the optical analyses. In summary, dry needling is a technique that causes mild injury irrespective of the muscle tone.

Dry needling in active or latent trigger point in patients with neck pain: a randomized clinical trial

The purpose was to determine the efficacy of deep dry needling (DDN) applied on an active myofascial trigger point (MTrP) versus a latent-MTrP versus a non-MTrP location, on pain reduction and cervical disability, in patients with chronic neck pain. A randomized, double-blind clinical trial design was used. A sample of 65 patients was divided into non-MTrP-DDN, active-MTrP-DDN and latent-MTrP-DDN groups. The visual analog scale (VAS), reproduction of the patient's pain, number of local twitch responses, pressure pain threshold (PPT) and Neck Disability Index (NDI) were assessed before, during and after the intervention and up to 1 month post-intervention. The active-MTrP-DDN-group reduced pain intensity more than non-MTrP-DDN-group after a week and a month (P < 0.01), as well as showing the greatest improvement in tibialis muscle PPT. The treatment of both Active and Latent MTrPs was associated with the reproduction of the patient's pain. The application of DDN on an active-MTrP in the upper trapezius muscle shows greater improvements in pain intensity after 1 week and 1 month post-intervention, compared to DDN applied in latent-MTrPs or outside of MTrPs in patients with neck pain.