There are three main reasons for the tightness and stiffness of the muscles in the thigh area: the first is that the quadriceps muscle in the thigh area is strained, forming local swelling and inflammatory edema, and the stimulation after the injury causes the muscle to be in a more tense state, which can lead to tightness and stiffness in the thigh muscles. The second, due to local muscle strain, such as strenuous exercise or walking too much, resulting in continuous tension and fatigue of the thigh muscles, and over time strain, will also form a sterile inflammatory lesion. Inflammatory metabolites will stimulate the muscles in the thigh area, which will also lead to muscle tension, tightness and stiffness. In the third case, the anterior thigh muscles become cold, because the accumulation of inflammatory metabolites can occur after the cold, leading to a further increase in the surrounding irritation. As a result of cold, the blood supply from the small blood vessels traveling through the muscle decreases, and the arterial blood supply decreases, leading to a relative decrease in blood supply to the muscle, resulting in muscle tension; and the venous return is affected, further accumulation of inflammatory metabolites will also aggravate the tightness and stiffness.