Effects of Dry Needling on Electromyographic Activity and Ultrasonographic Characteristics in Post-Stroke Spasticity

Participants assigned to the dry needling group will receive a weekly session for four weeks of ultrasound-guided dry needling in the inner gastrocnemius muscle with disposable stainless-steel needles, according to the depth of the muscle to be treated. For the realization of the technique, the diagnostic criteria of the Dry Needling in Hypertonia and Spasticity technique (DNHS®) developed by Herrero et al. will be applied adapted to the characteristics of the study, as well as the procedure for its application. The ultrasound guidance will be the same ultrasound device than in the assessments. This ultrasound-guided intervention allows to guarantee the safety of the approach, to have the certainty in the location of the target structure and to see the responses of local spasm. During the application of the technique, patient will not look at the ultrasound screen to ensure the blindness of the patient to the group allocated.

Participants assigned to this group will receive the same assessments, the same number of sessions, and the sham dry needling at the same site as the dry needling group, but with a sham intervention, where the needle is dropped through the guide tube and touch the skin. The patient will not feel anything, or at most that the needle touches the skin, since it does not get into the subcutaneous cell tissue, as placebo interventions were performed in similar studies. The context will be simulated in its entirety, using the same ultrasound and disposable needles for the intervention. Both groups will continue their daily motor rehabilitation treatment during the 4 weeks, which consists of strength training, balance, motor control, gait training, and mass practice oriented to tasks of intensity and duration appropriate to each patient, allowing the fastest possible clinical improvement, as recommended by clinical practice guidelines.