Updated: Sep 6, 2021
A hip hinge is simply the flexion and extension of the hip joint, the articulation between the head of the femur and the acetabulum of the pelvis. The movement can occur when the pelvis moves on a fixed femur, for example a dead lift pattern. The movement can also occur when the femur moves on a fixed pelvis, for example a scissor exercise for the abdominals, when you are lying supine.
It’s really important to teach clients to be able to differentiate between a hip hinge and using other joints to compensate, often the lumbar spine. We do this in many Pilates exercises without really thinking about it. A great learning tool is to go through your repertoire and see how many exercises you can spot that teach hip dissociation. (the movement of the femur within the acetabulum, while maintaining a chosen spine shape.)
Gym settings aside, a hip hinge is also used in everyday functional activities.