I was playing around with foot position during a seated calf raise (using a machine leg press machine). I pointed my toes together like in the photo link below. http://www.popsugar.com/fitness/photo-gallery/31081972/image/31081977/Calf-Raises-Internal-Rotation During the move my right hip 'popped', it's an area that has had some mobility issues in the past, and pain. After the initial discomfort of the pop my hip felt surprisingly good. I did a little review which suggests that rotation of the foot position may be beneficial for the calves. http://blog.brianschiff.com/?p=877 http://www.nsca.com/education/articles/does-foot-position-matter-with-the-calf-raise-exercise/ I didn't have any similar popping feeling during 'straight footed calf raise' in my hip. I'm curious of how the foot position on the calf raise improved the positioning and reduced the pain in my hip. My hypothesis is the change to the 'head of the gastroc' mentioned in the first quote. Is this likely? The other possibility was that it was the pressure of the weight itself driving my hips in? Though it was only 50% bodyweight, my legs were at full extension (it is a calf raise). Sometimes things are known to "unlock" during exercise. Will continually doing this help my hip, or hinder it? I could isolate the calf raise with only bodyweight, or keep doing them under weight- Placing different levels of "popping potential" on the vulnerable link in the chain. Thoughts?