EFFECTS OF ELASTIC WRAP ON MUSCLE ACTIVITY AND ISOMETRIC FORCE OF KNEE EXTENSORS

Abstract

ABSTRACT Introduction: The elastic knee wrap (EKW) is a device used by powerlifters, weightlifters and subjects undergoing strength training with the aim of stabilizing the knee joint and increasing the development of strength (carryover effect). Objective: To compare the effects of elastic knee wrap use on muscular activity of the vastus lateralis (VL) and on knee extension force during maximum voluntary isometric contraction (MVIC) on the knee extensor chair. Methods: The study included 18 healthy male strength trained (>1 year) subjects (age: 25.56 ± 4.84 years, total body mass: 81.83 ± 8.73 kg, height: 176 cm ± 5.17). Three five-second maximum voluntary isometric contractions (MVICs) of the knee extensors were performed with a 10-second interval between attempts, for each experimental condition: control (C), with elastic knee wrap (EKW), and with tensor (T). The performance of the knee extensors and VL muscle activity were evaluated. A repeated measures ANOVA was used to compare the dependent variables (carryover, peak force, IEMG and Impulse). Results: For carryover, the use of EKW presented a higher value (74.21%) than the control condition (p <0.001, d = 0.96) and was 79.37% higher than the tensor (p <0.001, d = 0.97). Peak force was 12.2% higher in condition C compared to EKW (p = .018, d = 0.71). For impulse, the control condition presented an increase of 8% compared to EKW use (p = .015, d = 0.62). No significant differences were observed for IEMG. Conclusion: Elastic knee wrap use increased strength production capacity during knee extension. The removal of the mechanical effect originating from carryover during MVIC reduces the strength performance of the knee extensors, but not the muscular activation of the VL. Level of Evidence I; Therapeutic studies - Investigation of treatment results.