Electrical Stimulation vs. Static Stretching in the Leg Muscles

Effect of Electrical Muscle Elongation vs. Static Stretching in the Leg Muscles Contracture

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.

Study Overview

• Status: Completed
• Conditions: Muscle Fatigue
• Intervention / Treatment: Other: Static stretching; Device: Electrical muscle elongation

• Study Type: Interventional
• Enrollment (Actual): 56
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Spain
  • Seville, Spain, 41008
    • Área Clínica de Podología

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Subjects affiliated with or related to the University of Seville.
• Those with muscular shortening of the posterior chain of the limb.

Exclusion Criteria:

• Subjects who engage in sports activity above the average of the sample or who follow an organized stretching program for the posterior leg muscles.
• Hyperlaxity
• History of musculoskeletal, neuromuscular injuries, joint disease, surgery on the lower leg, or serious illness.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Experimental: static stretching; Passive static stretching of the posterior leg muscles. Single session of 30 seconds per 4 sets with 30 seconds of rest	Other: Static stretching; A passive static stretch of the posterior leg muscles will be performed with the subject in a supine position and knees extended, starting with the ankle at 90º and continuing until reaching the maximum tolerated dorsiflexion.
Experimental: Experimental: EME; Electrical muscle elongation with interferential current. Dosage: 4kHz frequency and 100Hz frequency modulation amplitude. Self-adhesive surface electrodes (50x90 mm) and SONOPULS-492 equipment. Single session of 30 seconds per 4 sets with 30 seconds of rest.	Device: Electrical muscle elongation; The intervention will be performed with the subject in a supine position with knees extended. Electrodes will be placed on the gastrocnemius muscles of the leg being assessed. The parameters will be selected. Static stretching will begin until resistance is felt, at which point the intensity of the electrical current will be increased to induce a visible and tolerable contraction. Simultaneously, the subject will be asked to perform an isometric contraction of the antagonist muscles, resisted by the investigator. When the subject feels the stretch again, the intensity of the current will be increased once more until a new movement barrier is reached.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Evaluation of the ankle range motion	Assessment will be conducted in a prone position using a two-arm goniometer with the knee flexed and extended, as well as in a standing position with a digital inclinometer with the knee flexed and extended. Additionally, the distance from the big toe to the wall will be measured with a tape measure. This evaluation is carried , before and after a electric stimulation to compare if this measure may be different after this intervention At the beginning, during the intervention and a week later.	Through study completion, an average of 2 weeks.
leg muscular force	Assessment will be conducted with the subject in a supine position and with knees extended. The plantarflexor strength of the ankle will be measured using a portable dynamometer. Three measurements will be taken, and the average will be calculated. this measure is carried on to evaluation if the force of the posterior leg muscles may be increased At the beginning, during the intervention and a week later.	Through study completion, an average of 2 weeks.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Patient Global Impression of Improvement cuestionarie	A questionnaire indicating the global impression of improvement after the intervention will be administered at the end of the study. It is to assesment is this study it is confortable for the patient The scale has a total score from 1 to 7. A value of 1 indicates great improvement and a value of 7 indicates that the patient is very unwell.	At the end of the study, an average of 2 weeks

Collaborators and Investigators

• Sponsor: University of Seville
• Investigators: Principal Investigator: Aurora Castro PhD, University of Seville

Publications and helpful links

General Publications

• Mizuno T. Combined Effects of Static Stretching and Electrical Stimulation on Joint Range of Motion and Muscle Strength. J Strength Cond Res. 2019 Oct;33(10):2694-2703. doi: 10.1519/JSC.0000000000002260.
• Espejo-Antunez L, Lopez-Minarro PA, Garrido-Ardila EM, Castillo-Lozano R, Dominguez-Vera P, Maya-Martin J, Albornoz-Cabello M. A comparison of acute effects between Kinesio tape and electrical muscle elongation in hamstring extensibility. J Back Musculoskelet Rehabil. 2015;28(1):93-100. doi: 10.3233/BMR-140496.
• Espejo-Antúnez L, López-Miñarro PA, Albornoz-Cabello M, Garrido-Ardila EM. Acute effect of electrical muscle elongation and static stretching in hamstring muscle extensibility. Science & Sports. 1 de febrero de 2016;31(1):e1-7.
• Espejo Antúnez L, Maya Martín J, Cardero Durán MA, Albornoz Cabello M. Aumento de la extensibilidad isquiotibial tras aplicar elongación muscular eléctrica. Fisioterapia. 1 de mayo de 2012;34(3):112-7.

Study record dates

Study Major Dates

• Study Start (Actual): June 1, 2024
• Primary Completion (Actual): July 31, 2024
• Study Completion (Actual): July 31, 2024

Study Registration Dates

• First Submitted: September 23, 2024
• First Submitted That Met QC Criteria: October 1, 2024
• First Posted (Actual): October 4, 2024

Study Record Updates

• Last Update Posted (Actual): December 19, 2025
• Last Update Submitted That Met QC Criteria: December 12, 2025
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Keywords: electric stimulation; Longitudinal; Achilles tendon; static stretching; Session duration; Comparision group; gastrocnemius muscle; articular Range of Motion; randomized Clinical trial; muscle shortening; Electric muscle elongation; triceps surae
• Additional Relevant MeSH Terms: Fatigue; Motor Activity; Movement; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena; Therapeutics; Physical Therapy Modalities; Patient Care; Exercise Therapy; Rehabilitation; Aftercare; Continuity of Patient Care; Exercise; Muscle Stretching Exercises
• Other Study ID Numbers: US-elect26

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No