Any practitioner who touches, moves, pokes, prods, or examines a patient, is providing that patient with altered afferent input.
Since we know that the withdrawal reflex is just one of the many reflexes that will operate when the patient is touched or moved, we know that any physical input will be altering muscle tone, the only issue is how long will those changes last?
As an example, consider foot reflexology. Whatever a reflexologist thinks they are doing by stimulating points on the feet, there can be no doubt they are stimulating nerve sensors and therefore, producing the withdrawal reflex. Although the leg may not move, there will certainly be facilitation (increased activity) of some muscles and inhibition of others.
If the calf muscles were to be facilitated by stimulation of the withdrawal reflex (and it is hard to see how they could not be), then the reflexologist would also be affecting the function of the adrenal glands and kidneys. Using micro electrodes inserted into the sympathetic nerves supplying the kidneys in cats and the adrenal glands in rats, researchers in Texas were able to measure the amount of nerve stimulation to those glands. (Sympathetic nerves regulate the activity of those organs.) They found that every time they rapidly stretched the calf muscles of the animals there was a burst of nerve activity to the kidneys and adrenal glands with every stretch. However, when they cut or blocked the nerves that take the afferent input from the calf muscle to the spine, the effect was lost. Even electrically stimulating the muscles produced an effect in the glands.
The limitation to the effectiveness of changing muscle tone via reflexology may arise in the fact that, after the therapy ends, the changes in muscle tone would also end. Our bodies are incredibly adaptable and tend towards their natural state unless the stress that changes them becomes permanent.
Acupuncture can likewise be explained in terms of altered afferent input. The insertion of needles induces the withdrawal reflex just like reflexology does. However, the needle’s effects will be more specific and far more powerful than simple pressure on the skin because the needle may physically damage nerve receptors. Therefore, the stimulation from those nerve receptors may last days to weeks after the needles are withdrawn.
It is not my intention to negate the model of understanding that has served acupuncture so well for centuries. The theory of energy flowing through invisible channels is sophisticated and elegant, but that does not make it right. Afferent Input offers an alternative explanation for the practice of acupuncture.
Chiropractors and osteopaths also have theories about how their therapies work, yet often their theories cannot explain their results.
Chiropractors and osteopaths have always found that many of their patients feel better after manipulative treatment. In other words, they have felt not just relief from their pain, but better generally. Trying to explain the effects of manipulation as simple joint mobilisation does not allow the possibility that patients would have improvements in their overall health, despite that being a common finding in chiropractic and osteopathic offices all over the world.
If it is a lack of tone in the small muscles that support the vertebrae, and it is likely that this is the case, then this would account for the “fixation” of vertebrae that chiropractors and osteopaths detect and adjust.
Manipulation not only stimulates the joints of the spine, it will necessarily provoke the stretch or myotatic reflex, increasing the tone in the muscles that support the vertebrae. As the muscle spindles of the vertebral muscles start to fire, they move the vertebrae more effectively and that joint stimulation further stimulates the muscles in a positive-feedback loop. This is the neurological model of chiropractic, which fits what we see in practice has better than the panel-beating model.
Perhaps the patient’s increased wellbeing occurs because the manipulation stimulates increased muscle spindle activity, which boosts sensory input to the CNS. Indeed, we already know that chiropractic adjustment increases strength and it is likely that these increases in muscle tone also alter glandular function.
While Chiropractors have long said that they are “removing” subluxations, they are not removing anything physical like a bullet or a knife. They are only removing subluxations in the same was as turning a light on removes darkness. What they are doing, however is providing something, which is increased afferent input. Whether that increase in input comes from an adjustment, physical contact, an activator. soft tissue work or a toggle recoil, afferent input is the common denominator in all physical treatment.
While we all have our pet theories as to what is happening when we treat our patients, it’s important to strip away all the beliefs and just observe what is really happening. With understanding comes mastery.