Compare this situation to un-sticking a rusty hinge or a car wheel&endash; a short quick thrust on the wheel or hinge will free it up and it will start moving again.
When muscles become very tight, they can restrict the movement of the spinal joints they are joined to. The spinal joints then become a little stiff, and their mobility and movement begins to stiffen (and you feel your back stiffening up).
One way the reverse this and restore good movement to the joints is to put a short jerk movement through the back that literally just moves the spinal joints away from each other. When we do this movement, a quiet ‘pop’ is heard, that is often referred to in layman’s terms as ‘cracking’ the back. We know it as a “High Velocity Thrust” or HVT.
This is why we ‘Crack’ the back – to restore movement to the stiff joints of the spine.
The vertebral bones of the spine are lined up one on top of each other to form your spinal column. In order to allow you to bend forwards backwards and twist, the bones are not attached directly to each other, they are attached by membranes that form sacks that contain fluid. The fluid allows freedom of movement of the joints, without the bones grinding against each other, they lubricate the joints.
The fluid contains Nitrogen bubbles. When an Osteopath performs a ‘spinal manipulation’, we put a slight traction between the joints, just very quickly and gently gapping the joints to free them up and get freed off. When we do this, the Nitrogen bubbles literally pop, dispersing back into the fluid, giving the resultant ‘pop’ sound that you will have heard of. This relieves a lot of pressure in the joint and restores movement to the joint, by superlubricating it.
What will the ‘Crack’ feel like?
Strangely enough, you will feel very little discomfort. It doesn’t hurt, it just sounds a bit strange at first. Afterwards you will feel a lot more flexibility and freedom of movement, as the joints are freer and ‘unstuck’.
What will it feel like afterwards?
The way you feel afterwards can vary. Some people can feel fantastic and feel their movement is instantly returned and the pain is much reduced, whilst others may feel quite uncomfortable for a day while the body corrects, unwinds, and responds to the treatment. When muscles and joints become tight and stiff, the blood cannot flow freely through the spine, particularly to the disc. When you free up the tissues and get everything moving again,the blood flows more freely and can leave you feeling a little sore. This is a sign that your body is responding to treatment, and that you are on the way to feeling a lot better.