Okay, my SIL is too embarassed to post this question herself so I thought I'd ask for her. (She doesn't want to become known as the girl with the "butt problem", LOL) When doing calf raises on the machine (both standing and sitting)she says she feels it in her butt - but not in the muscle, internally. I think she said it was kind of like a pulling sensation inside there. Does anyone know what this is? She reads the boards here, so you can direct your answers to her. Just call her "J". Thanks!!!=)