Deloading tape reduces muscle stress at rest and during contraction

Abstract

Purpose: Taping techniques that aim to protect and reduce stress on an injured tissue during rehabilitation are common in sport. Called deloading tape, the mechanism of action is hypothesized to involve effects ranging from direct mechanical deloading of the underlying soft tissues to psychological effects on confidence. There is no evidence that deloading tape has direct mechanical effects. This study used an elastographic technique (supersonic shear imaging) to test the hypothesis that deloading tape applied to the skin over the rectus femoris would reduce stress within the taped area of this muscle. Methods: Thirteen healthy volunteers participated in this experiment. Muscle shear elastic modulus was compared between three treatments (no tape, deloading tape, and sham tape) in four conditions: three conditions without muscle contraction at different rectus femoris muscle-tendon unit lengths (moderately stretched, highly stretched, and shortened) and during submaximal isometric leg extension. Results: Although there was no effect of treatment when the muscle was shortened (P = 0.99), the shear elastic modulus was significantly affected by treatment for the three other conditions (all P ≤ 0.002). Muscle shear elastic modulus was significantly less during application of deloading tape than that during both the no tape and sham tape conditions (all P ≤ 0.001; e.g., vs no tape: moderately stretched, 8.4 ± 2.7 vs 6.7 ± 1.7 kPa; highly stretched, 25.2 ± 8.2 vs 14.4 ± 4.3 kPa; submaximal contraction, 21.3 ± 4.8 vs 14.2 ± 4.3 kPa). Conclusions: Through the use of elastography, this is the first study to support the hypothesis that deloading tape reduces stress in the underlying muscle region, thereby providing a biomechanical explanation for the effect observed during rehabilitation in clinical practice (reduce pain, restore function, and aid recovery). Further investigations are necessary to confirm these results in injured tissues.