We have four glute-ham developers (GHDs) at CrossFit Santa Cruz. We use them for back extensions and sit-ups. This month we explore the glute-ham developer sit-up, once more commonly referred to as a "roman chair sit-up."
The GHD sit-up was once a gym staple. In the gym today only rarely will someone be found doing other than back extensions on the GHD. In no small measure the decline of the GHD or roman chair sit-up coincided with the advent of the crunch. The crunch came to fashion on warnings and claims in popular media of the traditional sit-up’s destructive impact on the back.
It was argued that the GHD style sit-up's primary movers were the hip flexors and not the abs and consequently this sit-up, and sit-ups like it, were actually not good abdominal exercises. It was further argued that recruiting the hip flexors to lift the torso was destructive to the lumbar spine.