Physiology of Skeletal Muscle

Abstract

Skeletal muscle is a highly regulated, voluntarily controlled tissue. Coordinated muscle action via neurological and metabolic input is realized in various muscle fiber types. In general, these types include I, IIa, and IIx. The primary metabolic qualities of each type are slow, medium fast, and fast contraction speeds, respectively. Knowledge of fiber-type energy systems is paramount and initially discussed in relation to aerobic and anaerobic qualities of muscle action. Next, muscle force production via the sliding filament theory (SFT) is examined and underscored as the primary, basic pattern invoked to produce human locomotion or movement as muscle tendinous attachments pull on bone. Therefore, an understanding of the above fiber types and their ability to produce varying degrees of force may lead to better quality care during rehabilitation from injury. Finally, a brief discussion about various proprioceptors in muscles, joints, and tendons punctuates the chapter.