Different effect of local and general fatigue on knee joint stiffness

• Autores: Dan Wang, Giuseppe De Vito, Massimiliano Ditroilo
• Localización: Medicine & Science in Sports & exercise: Official Journal of the American College of Sports Medicine, ISSN 0195-9131, Vol. 49, Nº. 1, 2017, págs. 173-182
• Idioma: inglés
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• Resumen

  • Purpose: This study aimed to investigate the influence of locally and generally induced fatigue on the stiffness properties of the knee joint.

    Methods: Twenty-two male (24.9 ± 4.5 yr, 1.78 ± 0.06 m, 75.4 ± 6.4 kg, 23.9 ± 1.8 kg·m−2) and 18 female (21.1 ± 1.5 yr, 1.66 ± 0.05 m, 63.4 ± 6.5 kg, 22.9 ± 2.5 kg·m−2) amateur athletes participated. Peak torque (PT) of the knee extensor musculature, muscle stiffness (MS) of the vastus lateralis, and musculoarticular stiffness (MAS) of the knee joint were assessed pre- and postlocally and generally induced fatigue (undertaken on two separate days with a 1-wk interval).

    Results: Males were characterized by higher values of MAS, relaxed and contracted MS, normalized PT (PT/body mass), and normalized MAS (MAS/external load) irrespective of time point (P < 0.05).

    Locally induced fatigue: Contracted MS increased more (P < 0.01) and normalized PT decreased more (P = 0.03) in males than in females postfatigue. Significant increases occurred in MAS in females (P = 0.01); relaxed MS (males, P < 0.001; females, P < 0.001), contracted MS (males, P < 0.001; females, P = 0.04), and normalized MAS (males, P = 0.001; females, P = 0.01) in both sexes; and normalized contracted MS (contracted MS/external load) in males (P < 0.001). Normalized PT decreased significantly in males (P < 0.01) postfatigue.

    Generally induced fatigue: Contracted MS (P = 0.01) and MAS (P = 0.05) decreased significantly in males post-fatigue.

    Conclusion: The stiffness properties of the knee joint are influenced by locally and generally induced fatigue, with different responses being observed in males and females.