Defining hyperextension would probably be a wise place to begin to ensure we are all on the same flight-path in this discussion. Spinal hyperextension can be performed in a number of ways and at different levels of the spine, and although the term is generally associated with the lumbar [or lower] spine, it also commonly occurs at the cervical [or upper] spinal level.
OK, so what is it? Picture this; in a standing side-on position if you drew an imaginary line descending vertically from just behind the ear to the middle of the outside of the foot and then the hips were moved directly forward ahead of that imaginary line the lumbar spine would in fact be hyper-extending. By moving the chin forward of that same imaginary line and significantly tilting the head back you would be hyper-extending the cervical spine. Got the pictures?
Now that we've confirmed what hyperextension actually is, let's now transfer our focus to some of the ways we actually do this before deciding whether it is a good or bad practice to be employed in any sort of quest to reduce or eliminate back and/or neck pain. The commonly recommended activity of lying flat on your stomach with your hands beside your chest where you elevate your upper torso by doing a partial push-up using your arms while leaving everything from the hips and below in their original positions is a form of hyperextension.
Possibly stating the obvious but the habit of thrusting both hips forward while in a standing position in a pseudo stretch-like movement, done in the hope of creating a beneficial effect, is also a form of hyperextension. Swimming can result in hyperextension if done slowly because the hips, being the centre of gravity of the body, tend to sink more deeply into the water.
With a picture of these forms of hyperextension fixed in our thinking, let's ponder the question of whether hyperextension is likely to benefit or harm us if done on a regular and/or repetitive basis. At each of the spine's vertebral levels we find what are referred to as spinous processes. These processes are bony protrusions and are the points of attachment of muscles to the bony vertebral structure and they enable the tendons of the muscles to be effectively secured onto the bone. You can feel these nodular bumps down the middle of the back. Anterior of or in other words directly forward of these protrusions we find the spinal cord running down within the spinal column from which nerve roots emerge. If you have perhaps xperienced the excruciating pain known as sciatica you will be familiar with the extent of the pain nerve compression can generate and consequently when we are reminded of that level of pain we begin to grasp the potential for harm that hyperextension has been known to cause because of the resultant excessive nerve compression.
As the spinal column is hyper-extended these spinous processes as well as the tendons of the muscles attaching at those points are jammed closer together and as a result the potential for the nerves emerging from the spinal cord to be compressed increases significantly. This potential is compounded by the potential for irritation and inflammation of the tendons that are also being forcefully compressed. Additionally the pressure being brought to bear upon the posterior or rear aspects of the intervertebral discs also increases significantly. The frequency of degeneration or displacement of intervertebral discs is vastly higher in the forward direction than in any other, and by increasing the degree of pressure upon the posterior [rear] aspects of the discs, the likelihood of forward displacement or degeneration of the disc also increases dramatically.
OK, from that description are we to conclude that the activity of hyperextension is something we're not supposed to be doing? No, I am certainly not concluding that in any way. Hyperextension is clearly one of the movements the spine is capable of performing under normal circumstances however for those who are suffering chronic back and/or neck pain we are not talking about normal circumstances. For most sufferers the 'normal' spinal movements have at least temporarily become 'abnormally' difficult, and so to now introduce a movement that possesses a higher than necessary potential to traumatise further an already traumatised spine, we fail to demonstrate a whole lot of wisdom. Having later restored the spine to normal function, we might then, if done wisely and with an appropriate preparation and the essential de-compression afterward, hyperextend to the heart's content. Always bear in mind though, and as I make mention of in the book, 'hyperextension can be bad news for a bad back.'
The overwhelming and irrevocable deduction that not only I but thousands of others have ultimately arrived at over the years is that contrary to what many 'professionals' would mindlessly have you believe, there is no upside to including hyperextension as part of your initial rehabilitation program. Thankfully, though there are numerous suitable and particularly effective alternatives, and having then attained your own personal recovery and should you choose to you can later include hyperextension movements without running the risk of a recurrence of your former pain provided you respect the 3 essential primary principles of recovery; 1) symmetry restoration, 2) elasticity restoration of the soft tissue creating movement of the spine, and 3) restoration and maintenance of specific spinal support strength. When you do that, hyperextension represents not a single worry in the world, however if you ignore these principles, you could easily find yourself in a world that feels like it has come to a premature and painful end ?