Single-session measures of quadriceps neuromuscular function are reliable in healthy females and unaffected by age

• DOI: 10.1007/s00421-023-05395-x
• Publication Date: 2024-01-08T15:02:22Z
• Authors: Steven J. O’Bryan; Danielle Hiam; Séverine Lamon
• Keywords: Vastus medialis

Abstract Purpose This study aimed to determine the inter-session reliability of quadriceps neuromuscular function measurements in healthy young and older females. Methods Twenty-six females aged 19–74 years completed two identical experimental sessions on different days. Quadriceps included isometric maximal voluntary force, high- low-frequency twitch evoked (H-reflex, M-wave) electromyography (EMG), estimated torque, velocity power derived from torque–velocity relationships. Intra-class correlation coefficients (ICCs), variation (CoV) Bland–Altman plots assessed reliability. The effect age was by linear regression. Results Excellent (ICC > 0.8) shown for all mechanical outcomes. Vastus lateralis EMG outcomes showed excellent with CoVs < 12%, which were better than those vastus medialis rectus femoris . Age not associated 27/28 ( P 0.05). Conclusion force measured can be attained one session, irrespective age. Female accurately across lifespan minimal inconvenience, increasing feasibility future research. random error should however considered when quantifying age-related differences function.