Stroke is a global health problem, with an incidence in Europe of 147/100,000 people per year. It is estimated that 43% of them present spasticity throughout the first year, causing disability, hindering mobility and functionality, which can generate comorbidity problems, which in turn hinders its improvement over time. Recently, high quality studies have conclude that there is a moderate level of evidence with large effect size in reducing spasticity with dry needling, as well as being cost-effective in stroke patients in both the subacute and chronic phases. However, due to the limitation of manual evaluations of spasticity, and it is necessary to look for measurement alternatives that complement it, such as the analysis of the electromyographic activity and the muscular structure measured with ultrasound. These data could provide objective, useful and complementary information to clinical assessments to be more specific and effective in the treatment of stroke patients. This randomized controlled trial aim to analyse the effect of dry needling in this parameters in patients with stroke and spasticity, as well as correlated with gait variables. Each participant will be randomly assigned to the dry needling group or to the sham dry needling group, where participants receive a total of 4 sessions of ultrasound-guided dry needling or sham ultrasound-guided dry needling in the gastrocnemius medialis over 4 weeks, one per week. Measures of spasticity, electromyographic activity and muscle structure via ultrasound will made at baseline (T0) and immediate after each intervention (T1,T2,T3,T4). Gait variables will be made at baseline and after the last intervention (T0 and T4).