Hip Flexion vs Spinal Flexion Learning to hold the back rigid by Mark Rippetoe | December 31, 2015 In the deadlift, maintaining a rigid back is important both on the way up and when putting the bar down. Sometimes a brand new lifter will have difficulty understanding how to do this correctly because they haven’t ever needed to discern the difference between spinal flexion and hip flexion. Holding the back in rigid extension as the appendages move through full ranges of motion is key to pulling, squatting, and pressing heavy barbells. In this video, Rip corrects back flexion in a new lifter's deadlift finish. Discuss in Forums