Straighten the trail leg and keep weight forward
For a body-friendly backswing, let the trail (back) leg straighten instead of keeping it flexed and locked, and keep your weight over the front leg. Saguto says keeping the weight on the front side is what lets the hips turn more and the trail leg straighten, and that it takes stress off the lower back, knees and hips.
Channel: SagutoGolf
Watch official source at 18:07Why this context matters
Framed as a pain-free, play-forever swing change; runs opposite to the flexed-trail-leg model.