The Glute-Ham Developer (GHD)

Question 1

What is the definition of “core strength?”

Answer 1

Midline stabilisation

Question 2

What is “midline stabilisation?”

Answer 2

The ability to maintain rigidity, stability, and a lack of deflection about the reference line that trisects the spine and bisects the pelvis.

Question 3

What controls both sides of the torso?

Answer 3

The abs with the hip flexors control 1 side, whilst the hip extensors and erectors are involved in the other side.

Question 4

What are the best ab exercises known?

Answer 4

Static contractions for midline stabilisation. (GHD)

No amount of crunches will get you to same point as the L-sit, overhead squat or deadlift

Question 5

Work are the 4 GHD exercises used in CrossFit?

Answer 5

1. GHD Hip Extension
2. GHD Back Extension
3. GHD Hip and Back Extension
4. GHD Sit Up

Question 6

What exercise is incredible rehabilitating for the lower back?

Answer 6

GHD Hip Extension

Question 7

What does the “AbMat sit up” do to the hip flexors?

Answer 7

Takes them out of the equation all together.

Question 8

How do the “GHD” and the “AbMat sit up” compliment each other?

Answer 8

One is dynamic in the hips and static in the trunk (GHD sit-up), the other is dynamic in the trunk and static in the hip (ab mat.)

Question 9

Describe the GHD Hip Extension.

Answer 9

• There is no shortening of the trunk, just hip extension and flexion
• the erectors are being used statically
• the primary movers here are the Glutes and hamstrings working concentrically and eccentrically
• femur is on the pad and the pelvis is free (if trapped athlete won’t be able to hold lumbar curve)
• The hip extension is static in the trunk and dynamic in the hip.

Question 10

What are the changes from GHD Hip Extension to GHD back Extension?

Answer 10

• The pad is adjusted from femur to under the pelvis.
• the athletes deliberately surrenders the lumbar curve , thereby engaging in trunk flexion and extension.
• the erectors are now working statically and isometrically.

Question 11

What are the changes from GHD Back Extension to GHD hip and back Extension?

Answer 11

• the pad is adjusted back to the femur position
• starting from the bottom extend the spine, full flexion in the hip, the pelvis lifts first followed by a wave of contraction from the lumbar all the way to the cervical, finishing with a rhomboid pull back at the top
• initial movement comes from a powerful and dynamic glute-hamstring movement that extends the hip.
• then the back extends along the spine from “south to north”

Question 12

What are the changes from GHD Hip and Back Extension to GHD Sit Up?

Answer 12

• it involves no trunk flexion
• the athletes descends back to touch the ground and then comes back to seated position
• there is some leg flexion in the descent
• then the leg extends dramatically and pulls the athlete to seated.

Question 13

What muscle is used if the athletes does not extend their legs to gain a seated position during the GHD sit up, and where is it located?

Answer 13

The psoas muscle.

It comes off the femur, runs through the pelvis (without attachment) and attaches to the lumbar spine.

Question 14

What hip flexor is a very powerful complement to the psoas, and what does it attach to?

Answer 14

The Rectus Femoris (a dominant part of the quadriceps).

It does NOT attach to the lumbar spine, but attaches to the pelvis.

The leg cannot sharply extend without working the Rectus Femoris - a leg extensor and a hip flexor.

Question 15

How can you scale down the difficulty of the Ab Mat Sit Up?

Answer 15

Extend the legs to some degree