Hi there. I would truly appreciate if someone could help me translating the expression "undulating thighs" in the following context:"different signs of stress include clenched teeth, a furrowed brow, and undulating thighs." As you can see, the expression referrs to a physiological sign of stress; of course, I know the literal translation, "muslos ondulantes", but I would certainly not use such expression in Spanish, neither I have heard of it. Any ideas? Thanks a lot!