Simply put, it is the force generated by muscle cells pulling on each other. The tension of a muscle in a resting and relaxed state is called muscle tone. Muscle tone is the basis for maintaining various body postures and normal movements, and is expressed in various forms. For example, when a person is at rest, the tension in the muscles of the body is called resting muscle tone. When the body is standing, although no significant muscle contraction, but the front and back of the body muscles also maintain a certain tension to maintain standing posture and body stability, known as postural muscle tone. The tension of the muscles during movement is called motor tone, which is an important factor to ensure continuous and smooth muscle movement (no tremors, jerks, spasms).