The human musculoskeletal system consists of more than 600 bones building the skeleton. These bones are attached to other bones with joints and stabilizing ligaments. The flexibility is secured by more than 205 skeletal muscles which are attached to the skeleton by tendons. These tendons are the weak points of the structure. The regeneration and adaptation time of tendon tissues are increased in comparison to skeletal muscle tissues due to reduced vascularization. This fact leads to the danger of an imbalance of increased muscle growth e.g. by intensive training and a slowed adaptation of the tendon.

The human body differentiates three types of muscle tissue:

• Smooth muscle tissue (e.g. intestinal organs)
• Cardiac muscle tissue
• Skeletal muscle tissue
  
  

The differences of muscle tissue to other human tissues are at first the ability to contract, which means muscle cells, can shorten itself and generate force. As a second aspect the influence of nerve signals to muscle cells is the excitability leading to the contraction. The last two points are the extensibility and elasticity of muscle tissues.