Abstract
This 2024 study by Torres-Banduc et al., published in Sensors, investigates how the starting knee flexion angle (60° vs. 90°) affects muscle activity and performance during resisted plyometrics without jumping. Results indicate that commencing exercises at a 90° knee flexion position significantly increases vastus medialis and vastus lateralis muscle activity and enhances strength, power, and work compared to a 60° angle, regardless of limb dominance.
For athletes or rehabilitation patients looking to maximize quadriceps engagement and explosive power while minimizing joint impact, initiating movements from a deeper 90° knee flexion is more effective than a shallower 60° start. This emphasizes the importance of customizing knee flexion position for optimized muscle engagement.