[Load and stress of musculature. Some considerations from the mechanical viewpoint]

Injuries in the musculature belong to the most frequent injuries in sports. However, the various explanations regarding the reasons which lead to these problems differ considerably. In this work the muscle is simplified from a mechanical point of view and then explanations are derived in respect to possible origins of muscle injuries. The terms stress and distribution of stress are important in material science to describe the strength of a material. The same is true for the human body, for a muscle fibre or for an entire muscle. Due to its anatomical construction, the distribution of stress in the muscle is very inhomogeneous. It can be very large, even if the acting load is quite small. The most critical movements which lead to muscle injuries are fast, passive elongations of a muscle. The larger the rate of this elongation, the higher the risk of injury. These theoretical conclusions can also be supported by observations in everyday life. For example, muscle pain after exercise occurs almost exclusively after excentric loading.