Research Outputs
Intra-session reliability of knee flexion-extension muscle strength monitored using a functional electromechanical dynamometer in female soccer players
Background: The aim of the study was to analyze the relative and absolute reliability of intra-session comparisons of three repetitions in a protocol for assessment peak muscle strength in a knee extension and flexion exercise in competitive female soccer players. Methods: The participants in this research are professional level female soccer players. Peak muscle strength was assessed with functional electromechanical dynamometry (FEMD) for the knee muscles with the following movements: knee flexion (FLE) and extension (EXT). Each movement was assessed at a speed of 0.4 m·s-1 unilaterally, recording peak muscle strength values in the concentric phase (CON) and an eccentric phase (ECC). Results: Null differences (ES < 0.19) were detected in the measurements of peak muscle strength of the extensors and flexors of the right and left knee in their concentric or eccentric phases. In the intra-set reliability measures, they reported acceptable absolute reliability (CV% < 9.71) and extremely high relative reliability (ICC = 0.92–0.98). Conclusion: In relation to the results of this study, it can be concluded that the FEMD presents a high relative and absolute intra-series reliability for the evaluation of muscle strength in knee extension and flexion in female soccer players. These reported antecedents may facilitate a more specific evaluation of the function of the muscles of the lower limbs.
Bilateral strength balance of knee extensor and flexor muscles in female soccer players
Background: The aim of our study was analyze the bilateral strength balance of the knee extensor and flexor muscles in female soccer players. Methodology: Participated in this study twenty-three professional female soccer players. The volunteer participants of the study were eligibly if: (a) signing of informed consent, (b) 5 years of sporting experience as a soccer player and have experience with training and evaluation of muscle strength in the lower limb, (c) participate in five weekly training sessions (d) no musculoskeletal pathology in the lower limbs 6 months prior to the evaluation date. The assessment was performed unilaterally, with peak muscle strength values recorded using the FEMD device software at a constant velocity of 0.4 m s-1. The range of motion (ROM) was 90°–0° of joint extension in the sitting position and 150°–90° of flexion in the prone position. Each participant was required to perform their maximum effort for all repetitions. Results: Bilateral strength balance measurements were obtained in the range of 10.68%–13.80% for maximum muscle strength in knee extension and 13.27%–15.21%. No significant differences (p > 0.05) were found in the comparison of independent means for maximum muscle strength between the knee extension and flexion in the concentric and eccentric phases. Significant differences (p < 0.01) and small ES (ES < 3.32) were found in peak muscle strength measurements of the dominant and non-dominant lower extremity in the unilateral comparison of the extensor muscle and the flexor muscle group in the concentric and eccentric phase. Conclusion: In the analysis of bilateral strength balance, lower indices are presented in the knee extensor compared to the flexor, these bilateral indices would reveal intrinsic and extrinsic risk factors for musculoskeletal injuries in the hamstring muscles and anterior cruciate ligament of professional soccer players.