Normal aging alters in vivo passive biomechanical response of the rat gastrocnemius-Achilles muscle-tendon unit

• Verfasst von: Plate, Johannes [VerfasserIn]
• Verfasst von: Wiggins, Walter F. [VerfasserIn]
• Verfasst von: Haubruck, Patrick [VerfasserIn]
• Verfasst von: Scott, Aaron T. [VerfasserIn]
• Verfasst von: Smith, Thomas L. [VerfasserIn]
• Verfasst von: Saul, Katherine R. [VerfasserIn]
• Verfasst von: Mannava, Sandeep [VerfasserIn]
• Titel: Normal aging alters in vivo passive biomechanical response of the rat gastrocnemius-Achilles muscle-tendon unit
• Verf.angabe: Johannes F. Plate, Walter F. Wiggins, Patrick Haubruck, Aaron T. Scott, Thomas L. Smith, Katherine R. Saul, Sandeep Mannava
• Jahr: 2013
• Umfang: 6 S.
• Fussnoten: Available online 13 December 2012 ; Gesehen am 25.11.2021
• Titel Quelle: Enthalten in: Journal of biomechanics
• Ort Quelle: Amsterdam [u.a.] : Elsevier Science, 1968
• Jahr Quelle: 2013
• Band/Heft Quelle: 46(2013), 3 vom: 1. Feb., Seite 450-455
• ISSN Quelle: 1873-2380
• DOI: doi:10.1016/j.jbiomech.2012.11.007
• Datenträger: Online-Ressource
• Sprache: eng
• Sach-SW: Achilles tendon rupture
• Sach-SW: Aging
• Sach-SW: Fung QLV
• Sach-SW: Passive biomechanical properties
• Sach-SW: Quasilinear viscoelastic
• K10plus-PPN: 1779073437

Abstract

Predisposition to Achilles tendon (AT) ruptures in middle-aged individuals may be associated with age-related changes to inherent passive biomechanical properties of the gastrocnemius-Achilles (GC-AT) muscle-tendon unit, due to known muscle-tendon structural changes in normal aging. The goal of this study was to determine whether the passive biomechanical response of the GC-AT muscle-tendon unit was altered with age in 6 young (8 months) and 6 middle-aged (24 months) F344xBN hybrid rats from the National Institute on Aging colony. Fung's quasilinear viscoelastic (QLV) model was used to determine in vivo history and time-dependent load-relaxation response of the GC-AT. Effective stiffness and modulus were also estimated using linear regression analysis. Fung's QLV revealed a significantly decreased magnitude of the relaxation response (parameter C, p=0.026) in middle-aged animals compared to young animals (0.108±0.007 vs. 0.144±0.015), with similar time-dependent viscous GC-AT properties (τ1, τ2). The product of elastic parameters (A⁎B), which represents the initial slope of the elastic response, was significantly increased by 50% in middle-aged rats (p=0.014). Estimated GC-AT stiffness increased 28% at peak tensions in middle-aged rats (2.7±0.2N/mm) compared to young rats (1.9±0.2N/mm; p=0.036). While the limitations of this animal model must be considered, the changes we describe could be associated with the observation that GC-AT pathology and injury is more common in middle-aged individuals. Further studies are necessary to characterize the load-to-failure behavior of AT in middle-aged compared to young animals.