When the weather gets cold in winter, the left half of my brain will hurt, and my teeth will be so tight that I can’t open my mouth, like a cramp. What kind of disease is this?

Muscle Contraction

The mechanical response of a muscle to a single stimulus is called a single contraction. According to the changes in muscle length and muscle tension during muscle contraction,

Shortening contraction (concentric contraction)

Characteristics: The tension is greater than the external resistance and the muscle length is shortened.