Skeletal Muscle: Functional Parameters and Emerging Research Directions
Keywords:muscle physiology, exercise physiology, cross-bridge cycle, experimental myology, muscle mechanics
Skeletal muscle is an energy-consuming tissue, responsible for movement, which also performs multiple roles in the body, such as regulating metabolism and thermoregulation. Skeletal muscle myocytes (aka muscle fibers) contain myofibrils and these in turn contain the functional units of the muscle, the sarcomeres, an arrangement of interdigitizing filaments and their accessory proteins. In the present review, an overview of the mechanism of contraction and the role of known (actin, myosin, troponin) and relatively unknown (nebulin, titin) sarcomere proteins is presented. Additionally, emerging factors involved in the mechanism of muscle contraction, and exercise applications are discussed. Moreover, how these factors are likely to affect overall skeletal muscle performance in health and disease is commented upon. Last but not least, examples of the practical meaning of selected scientific data is highlighted for the benefit of the exercise professional or the physiology teacher, as well as novel or continuing research directions within the fields of exercise physiology and experimental myology are proposed for the benefit of the physiology researcher.