Jefferson curls are one of those exercises that tend to spark strong opinions online — either they’re viewed as “dangerous,” or they’re treated like a magic fix. The reality is a lot more nuanced. A Jefferson curl is a controlled, loaded spinal flexion exercise where you slowly articulate through the spine segment by segment while reaching toward the floor. The goal isn’t to lift heavy — it’s to improve mobility, control, and tissue tolerance through ranges many people avoid completely. I’ve been incorporating them carefully during my own low back recovery after a tweak to gradually reintroduce spinal flexion in a controlled way. Here’s the important part: Spinal flexion itself is not inherently bad. Your spine is designed to move. Problems usually come from excessive load, poor timing, lack of control, or doing too much too soon. Jefferson curls can be useful for: • Building mobility through the posterior chain • Improving spinal segmentation/control • Increasing tolerance to flex...