If your hamstrings cramp or your lower back arches when you bridge, it’s not just tightness, it’s a sign your hamstrings aren’t controlling your pelvis. This exercise retrains posterior chain stability so your glutes and hamstrings share the load evenly instead of your back taking over. When the hamstrings can contract through their full range while keeping the pelvis neutral, the nervous system stops “guarding,” and those cramps fade fast. ✅ Builds pelvic control ✅ Strengthens hamstrings eccent