Vastus lateralis and medialis muscular activation during frontal and sagittal single-leg jumps in sportswomen.

Introduction: Differences in the lateral and medial portions from quadriceps muscular activation during the execution of the jump can become a neuromuscular risk factor raising knee dynamic valgus and increasing the risk for anterior cruciate ligament injury. Objective: To determine the difference in the activation of the lateral and medial vastus using surface electromyography during single-leg jumps in the sagittal and frontal plane in female athletes. Materials and methods: This was a quantitative, cross-sectional study. A total of 64 female athletes participated. We carried out anthropometric measurements, vertical and lateral single-leg jump tests with the evaluation of vastus medialis and lateral electromyographic activation during the tests and iliotibial band flexibility assessment. Results: There was a statistically significant relationship (p≤0.05) between the body mass index, fat percentage, and vertical single-leg jump power. We also found statistical significance (p≤0.05), with greater activation of the lateral vastus in the right lower limb vertical jump and in the lateral jump in both lower limbs. Conclusion: The athletes presented differences in quadriceps activation, showing higher lateral vastus activation in most of the single-leg jumps, both in the sagittal and frontal plane. This may increase the risk for suffering knee injuries during sports practice.