Can Myotonometry Quantify Dry Needling Effectiveness on Myofascial Trigger Points?

The main objective of this study is to assess effects of Dry Needling into Myofascial Trigger Point compared Dry Needling into Taut Band point based on the outcomes of myotnometric measurement in healthy subjects. Hypothesis: Deep Dry Needling of the latent medial Myofascial Trigger Point (MTrP) of the soleus muscle will achieve changes in myotonometric measures compared to Deep Dry Needling of the Taut Band of the soleus muscle.

Methods: It is a double-blinded randomized clinical trial where subjects are healthy volunteers from the city of Toledo older than 18 years. There will be a MTrP Group (dry needling into the medial MTrP of soleus muscle) and a TB Group (dry needling distal to the MTrP but into the taut muscle band of soleus muscle). The intervention will be a unique session. Intervention: Dry needling technique will be performed by locating the taut band and the Myofascial Trigger Point. Depending on the group, a thin needle (0,32x40mm) is introduced 10 times (fast in and fast out) directly within the Myofascial Trigger Point or within the Taut Band. Assessment: Myoton device is a simple and portable tool to obtain quantitative and objective assessments of mechanical properties of muscle tone. Myoton has been adopted to characterize the viscoelastic properties of skeletal muscle as tissue displacement when a mechanical perturbation is applied to the muscle. The device incorporates a probe and an acceleration sensor. The probe was kept perpendicular with its end touching the muscle belly. 10 mechanical impacts (with a duration of 15 ms, a force of 0.4 N and a local deformation in the order of a few millimetres) are delivered to MTrP and TB points. Outcome measures: Outcome measures will include myotonometric measurements (frecuency, stiffness and decrement) and they will be evaluated before, at 10 min and 1 week after the intervention.

TB Group: Deep Dry Needling distal to Myofascial Trigger Point of the soleus muscle (in the same taut band; out of MTrPs).

Deep Dry Needling into the site of the latent medial Myofascial Trigger Point of the soleus muscle. 1 session in soleus muscle. 10 fast in and fast out needle insertions.

Deep Dry Needling distal to Myofascial Trigger Point but into the same taut band. 1 session in soleus muscle. 10 fast in and fast out needle insertions.

This outcome measure is obtained by a device named MyotonPro. The frequency of the damped oscillations characterizes the muscle tone.

This outcome measure is obtained by a device named MyotonPro. Stiffness reflects the resistance of the muscle to the force deforming the muscle.

This outcome measure is obtained by a device named MyotonPro.The logarithmic decrement of the damping oscillations characterizes muscle elasticity which is the ability of the muscle to restore its initial shape after contraction.

Inclusion Criteria: Age range 18-40 years. Healthy volunteers. Presence of a latent medial MTrP of the soleus muscle. Being able to provide written informed consent. Being able to follow instructions and realize clinical tests. Exclusion Criteria: Any history of ipsilateral lower limb severe injury or intervention (e.g. fracture, surgical intervention). Pain or musculoskeletal injury, ligament injury, tendonitis or plantar fasciitis in the ipsilateral leg for six months previous to the intervention. Peripheral or central nervous system neurological disease. Altered sensitivity in the treatment area. Treatment of a myofascial trigger point in the sural triceps in the six months previous to the intervention. Changes in physical activity which would have affected muscle tone during the study. Fear of needles. No tolerance to pain caused by dry needling. No continuance commitment.