For many movements, we tell you to bend at your hip and not to bend or flex your back. It’s important to understand what is meant by “hip” and “back” in this context.
Figure 1 - Deadlift, demonstrating hip flexion
Bending of the hip refers to flexion of the acetabulofemoral (AF) joint, which is the ball-and-socket joint formed by the femur and acetabulum. Figure 1 is a skeletal view of a proper deadlift. The red circle indicates the hip joint, which is in flexion.
To feel what it’s like to bend at your hip, stand up straight and grab the bony part of your hip that sticks out toward the side, just below your waist (this is called the iliac crest.) Now bend forward so that you can feel your pelvis tilt. This is hip flexion.
Figure 2 - Diagram of the spine
The phrase, “bending the back” is not as precise. By this, we generally mean flexion of the lumbosacral joint or between any of the lumbar or thoracic vertabrae. Figure 2 is a labeled diagram of the spine (click to enlarge). The lumbosacral joint is the joint between L5 and S1. The lumbar vertabrae are L1 through L5 and the thoracic vertabrae are T1 through T12.
To put it more simply, “bending the back” is any flexion of the lower or middle back.
Figure 3 - Top: hip flexion only; Middle: back flexion only; Bottom: hip and back flexion
{ 2 comments… read them below or add one }
I have actually never had “formal” training on the GHD- so this was good to know!
Are we doing back extensions or hip extensions today on the GHD, or both?