Comparison of Rate of Force Development between Explosive Sustained Contractions and Ballistic Pulse-like Contractions during Isometric Ankle and Knee Extension Tasks

Background: The rate of force development (RFD) is a measure explosive strength, commonly evaluated within the same repetition as peak force/torque, by instructing participants to produce “fast” and “hard” contraction. Previous studies have indicated that attempting achieve maximal RFD force/torque contraction may not be optimal. Methods: This study assessed differences between sustained (“fast-and-hard”) ballistic (pulse-like) contractions on during isometric ankle knee extensions in young, recreationally active (n = 33; age: 23.4 ± 5.6 years). performed both types for extension tasks. was calculated time intervals 50, 100, 150 200 ms from onset also these points (50–100, 100–150 150–200 ms). Findings: results this showed higher later (100–150 ms) compared (effect size (Hedge’s g) 0.51–0.73). ballistics were larger occurred more outcome variables females than males. Peak contractions, (p 0.010; Hedge’s g 0.54) males 0.003; 0.78). intra-session reliability similar types, increasing moderate excellent with longer intervals. Conclusion: Our suggest should used when assessment primary goal. When aim assess force, it suggested use combination separate protocol.