Hanging knee and leg raises are the gold standard in core training. They require strength and stability along your entire spine as well as strong hips. They also demand flexibility in the lower back to complete the package.
The biggest threat to your progress is the tendency to generate a lot of momentum which can cause swinging. This swinging robs your abs of valuable tension plus it can place more stress on your shoulders and wrists.
By using your back and hips in a more effective way you’ll regain full control of your body in space so you can take full advantage of this fantastic abdominal move.