Mechanical properties of type I and type IIB single porcine muscle fibres
M Christensen1, C Kok, P Ertbjerg
1The Royal Veterinary and Agricultural University, Department of Food Science, Rolighedsvej 30, DK-1958 Frederiksberg C, Denmark.
Abstract:
Single muscle fibres were isolated from longissimus dorsi (LD) and vastus intermedius muscles at 1 or 8 days post-mortem. Fibres were classified as type I or IIB and their mechanical properties determined. In LD day 1, individual type IIB fibres fractured at higher (P<0.001) loads and lower (P<0.001) stress values than type I fibres. The strength of type I fibres did not differ between muscles. Storage for 8 days decreased (P<0.001) breaking stress of type I fibres, whereas the breaking stress of type IIB fibres did not change. In conclusion, type IIB fibres were weaker per cross-sectional area than type I fibres in LD. The mechanical properties of type I fibres did not differ between muscles and the change in strength with post-mortem storage were more marked in type I than in type IIB fibres.
Related Concept Videos
Types of Skeletal Muscle Fibers
Fast-twitch fibers
Fast-twitch fibers, or Type II fibers, are designed for quick, powerful bursts of speed and strength. They reach peak tension within approximately 0.01 seconds following stimulation. Characterized by a large diameter and densely packed myofibrils, these fibers contain...
Classification of Skeletal Muscle Fibers
Slow-Twitch Muscle Fibers
Slow oxidative, muscle fibers appear red due to large numbers of capillaries and high levels of...
Overview of Muscle Tissues
Elasticity
Elasticity is the ability of muscles to stretch and return to their original shape. This property is partly due to elastic fibers — macromolecules that run through the muscles. These fibers are firm and resilient,...
Isotonic and Isometric Muscle Contractions
Isotonic contractions
Isotonic contractions occur when a muscle changes length while the...


