Electrical Stimulation vs. Static Stretching in the Leg Muscles

The retraction of the posterior leg muscles consists of a shortening of the muscle fibers that limits ankle dorsiflexion. The objective of this randomized controlled clinical trial (RCT) with a double-blind technique and longitudinal chronology is to evaluate the short-term effect of electrostimulation associated with muscle stretching (electrical muscle elongation technique or EME) compared to static stretching in adult subjects with shortening of the posterior leg muscles. The main questions it seeks to answer are: * Are there significant differences in the short-term effect of electrical muscle elongation versus static stretching exercises on the gastrocnemius complex and Achilles tendon in young adults? * Does the ankle\'s range of motion increase in both weight-bearing and non-weight-bearing positions? * Does muscle strength increase in ankle plantar flexion? The researchers will compare the group receiving electrical muscle elongation with interferential current to the group receiving passive static stretching to assess whether there are significant differences in the effects on the ankle\'s range of motion and the muscle strength of the posterior leg muscles. Participants in this study will perform the following tasks: * Receive a session of electrical muscle elongation with TENS and static stretching performed by the researcher. * Follow the instructions during the intervention. * Undergo evaluations of ankle range of motion and plantar flexor muscle strength * Record their level of satisfaction after the study.