Hip opening poses typically target several different muscles in the pelvic region. While many of us associate hips with the thighs, there's a lot more to this muscle group. These muscles are commonly referred to as hip flexors, groin muscles, gluts and lower back muscles. They are especially vulnerable to tightness for people engaged in repetitive motion involving these muscles. Runners, cyclists, or professions requiring you to be in one position for extended periods (sitting or standing) can all contribute to tight hips. Creating more flexibility in the hips can actually improve overall stability in the body and alleviate pain in the areas pictured below.