One of the most challenging movements to achieve is stabilization of the lumbar spine with hip extension. The reason is that virtually every human being lacks efficient hip extension. The compensation for a lack of hip extension results in excessive extension in the spine in younger people and flexion of the spine in older people. This is, in my opinion, one of the major reasons that lower back pathology is a pandemic in society.
Various authors state that normal hip extension is as little as 10 degrees and as much as 50 degrees. (Note that these authors do not state whether the lumbar spine was stabilized when the range of motion measurements were taken.) I believe it to be 30 degrees without compensation of the lumbar spine as this is the amount of hip extension needed to ambulate with a efficient gait pattern.
The following is an awesome activity to do with your clients to disassociate stabilization of the lumbar spine with hip extension. My class and I came up with it in our Balance and Gait Class.
As see in the photo to the left, have your client stand behind a chair and wrap a towel or a strap around the lumbar spine or at the particular segment or vertebrae that you are trying to stabilize. Apply a forward force with the towel so the patient engages their abdominal core stabilizers and the patient can resist without straining. The patient may hold onto the back or the chair for support or on the therapist's shoulders.
In the photo in the right, ask the patient to hold their trunk stationary maintaining the pressure of their back on the towel as they move one leg posterior so that the toes of that leg are parallel with the heel of the leg that is not moving (this is the equivalent of 30 degrees of hip extension). Have the patient repeat or alternate legs moving posterior.
To see a video of this activity, click the link: http://www.youtube.com/watch?
Just a footnote, if your client is not able to perform the activity without compensation, there is either a structural or non structural dysfunction of the thigh, pelvis, sacrum or a non-structural dysfunction in the lumbar spine that needs to be addressed first.
