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

Introduction This study examined the effect of a single treatment of Active Release Techniques (ART ® ) on resting stiffness of the medial gastrocnemius (MG), resting tension of the triceps surae unit, plantar-flexion strength, and active ankle range of motion (ROM). Methods Twenty-four healthy participants (14 females, mean (SD) age: 24.8 (4.6) years) were randomised to 4 min of ART ® applied to one leg. With the foot fixed in 5° plantar-flexion, shear wave velocity (SWV) was measured using ultrasound elastography and resting tension was measured using a dynamometer, acquired before, immediately, and 5 min post intervention. Active ankle ROM and plantar-flexion maximal voluntary isometric strength (MVIC) were measured before and after ART ® . Repeated measures ANOVAs with factors of limb and time were used. Results MG SWV of the intervention limb decreased immediately following ART ® (mean % change = −5.65% [95%CI: −2.05 to −9.26], p = 0.003) and at 5 min (mean % change = −5.50% [95%CI: −1.22 to −9.78], p = 0.017). There was no difference post ART ® for resting tension of the triceps surae unit, plantar-flexion MVIC, or active ankle ROM for either the intervention or control limb. Conclusion Four minutes of ART ® applied to the MG induces a significant reduction in resting MG SWV, which persisted for 5 min, but was not coupled with a change in resting tension of the triceps surae unit, plantar-flexion MVIC, or ROM.