Comparison of Immediate Effects of Fascial Distortion Model and Static Stretching on Mechanical Properties of Soft Tissue and Range of Motion in Patients with Chronic Ankle Instability

Purpose: This study compared the immediate effects of a one-minute application of the fascial distortion model and four-minute static stretching on soft tissue viscoelasticity and range of motion in young men with chronic ankle instability, reflecting the recommended minimum effective clinical time for each technique.Methods: Fifty young men with chronic ankle instability were assigned randomly to either the fascial distortion model group (n= 25) or the static stretching group (n= 25).The fascial distortion model group received the Triggerband and Cylinder techniques for one minute on the fascia surrounding the medial gastrocnemius, while the stretching group performed static stretching for four minutes (six sets of 30-second holds).The muscle tone and stiffness were measured using MyotonPRO, and the ankle dorsiflexion range of motion was assessed using the Weight-Bearing Lunge Test.An analysis of covariance was used to calculate the partial η² effect sizes.Results: The fascial distortion model group showed significantly larger decreases in muscle tone (p= 0.033, partial η²= 0.093) and stiffness (p= 0.042, partial η²= 0.085) than the stretching group, along with a significantly greater improvement in the dorsiflexion range of motion (4.34° vs. 2.63°, p= 0.001, partial η²= 0.226).Conclusion: A one-minute fascial distortion model yielded significantly greater immediate improvements in soft tissue properties and dorsiflexion ROM than four-minute static stretching in young men with chronic ankle instability.This combined technique-time effect supports its use as a time-efficient intervention.