Active release techniques^® reduces stiffness in the medial gastrocnemius measured using elastography

Area of Science:

• Biomechanics
• Musculoskeletal Ultrasound
• Sports Medicine

Background:

• Active Release Techniques (ART) is a soft tissue therapy.
• Understanding ART's immediate effects on muscle properties is crucial for clinical application.
• Medial gastrocnemius (MG) stiffness and ankle function are important in athletic performance and injury.

Purpose of the Study:

• To investigate the acute effects of a single ART session on the medial gastrocnemius (MG) muscle.
• To assess changes in resting muscle stiffness, resting tension, plantar-flexion strength, and active ankle range of motion (ROM) following ART.

Main Methods:

• Twenty-four healthy adults received a 4-minute ART intervention on one leg.
• Ultrasound elastography measured MG shear wave velocity (SWV) for muscle stiffness.
• Dynamometry assessed triceps surae resting tension and plantar-flexion maximal voluntary isometric strength (MVIC).
• Active ankle ROM was measured before and after the intervention.

Main Results:

• A significant decrease in MG SWV (stiffness) was observed immediately after ART and persisted for 5 minutes.
• No significant changes were found in triceps surae resting tension, plantar-flexion MVIC, or active ankle ROM.
• These effects were specific to the intervention limb.

Conclusions:

• A single 4-minute ART session effectively reduces resting stiffness of the medial gastrocnemius.
• The observed reduction in muscle stiffness persisted for at least 5 minutes post-treatment.
• ART did not acutely alter resting muscle tension, maximal strength, or active range of motion in healthy individuals.