What is the origin of the idiom "thunder thighs" and when to use it?

The idiom "thunder thighs" refers to someone who has large or muscular thighs. It originates from the association of thunder with loud and powerful sounds, and thighs with their strength and size. It is generally used in a humorous or lighthearted manner to describe someone with notably large thighs. It can be used to refer to individuals with muscular or overweight thighs, often in a playful or teasing context. However, it is important to be mindful of the potential for body shaming or causing offense, so it's recommended to use this idiom with caution and sensitivity.