Throughout history, adjustments, or spinal
manipulations, have been performed to help relieve people of back
and neck pain. Hippocrates,} the father of modern medicine, utilized
spinal manipulation in his practice 2,500 years ago. For more than
100 years Chiropractors have been the specialists in spinal
adjustments. About 95% of all spinal adjustments today are performed
by Chiropractors. Doctors of Chiropractic are highly trained and
skilled in the art of adjustments and manipulations.
What Is An Adjustment?
Adjustments and manipulations are techniques used to
restore motion to joints that have lost their ability to move
normally. To fully understand, we must first learn about normal
All joints have an active and passive range of motion. Active range
of motion is the movement a joint makes using only your muscles.
Move a finger back and forth and notice how far it moves. At the end
of its motion you can push on your finger and it will move a little
farther. This extra motion is the passive range of motion. The joint
should give or spring as you push it into the passive range.
At the end of the passive range of motion is an area called the
paraphysiological zone. The goal of adjustments is to move the joint
beyond the passive range of motion and into the paraphysiological
As the joint is moved into this special zone a popping sound is
usually heard. This requires great speed and skill and should only
be done by someone who has had extensive training. Adjustments may
be used on any joint of the body that has lost its normal joint
motion. Doctors of Chiropractic are specialists in performing
What Makes The Popping Sound?
When a joint is adjusted the two surfaces of the
joint separate. The popping sound is not made from the bones, but is
the collapse of a gas bubble formed in the joint fluid as the joint
is separated. It takes approximately
20 minutes for the joint surfaces to return to their previous
position and pressure. This is why many patients feel "loose" after
an adjustment. Adjustments allow the joint to have more freedom and
a greater passive range of motion.
How Do Adjustments Work?
effects of adjustments are very broad. They include various
mechanical, or direct, and reflex, or indirect, mechanisms. These
Increasing joint motion (mechanical) which causes a
decrease of pain (reflex). You have different types of nerves that
sense different types of sensations. The nerves that sense motion,
heat, cold, and vibration will override the nerves that sense pain.
This is why people will feel okay while they are active, but when
they sit down and relax their pain may come back. As the brain
receives information about movement and other sensations, it closes
the gate on the nerves that sense pain.
Stimulating a joint with an adjustment (mechanical)
causes relaxation of the muscles around the joint (reflex).
Chronic pain results in decreased joint mobility,
shortening of joint tissues, and the formations of adhesions.
Adjustments stretch shortened tissues and break joint adhesions.
This results in increased joint motion causing the reflexes noted
Sometimes a tag of joint tissue will become trapped
in neck or back joints. This may cause irritation in both the
affected and neighboring joints, which leads to muscle spasms and a
locked neck or back. Adjustments can release these joint tags
Spinal adjustments stimulates the autonomic nervous
system (reflex), which regulates the function of the organs. Some of
the effects include changes in blood circulation, skin temperature,
blood pressure, blood chemistry, and the diameter of the pupils.
Correcting abnormal joint mechanics provides relief
of chronic nerve compression and irritation. Some patients have a
combination of stenosis, or narrowing of the canals that the nerves
pass through, and decreased joint motion. Adjustments will increase
joint motion and relieve compression of the nerves, resulting in
reflex effects that reduce pain and muscle dysfunction.
Chiropractors have sometimes been criticized
throughout the past century for their use and claims of the
benefits of spinal adjustments. Every Chiropractor has witnessed
"miracles" in his or her office. Patients not only describe relief
of pain but also changes in their vision, bowels, amount of
dizziness, breathing, and sleeping. The list goes on and on. Each
year there are more research studies being done to explain these
In the 1980's, there was an explosion of research on the treatment
of back and neck pain; specifically concerning the effectiveness of
spinal adjustments. These research studies have been used to
establish US and UK clinical guidelines for the management of low
These government sponsored multidisciplinary guidelines recommend
spinal adjustments, over-the-counter drugs, and hot or cold
treatments as the only proven treatments as acute low back pain.
The US guideline recommends against most traditional, and unproven,
medical treatments including muscle relaxers and prescription drugs,
bed rest, traction, TENS units, ultrasound, and various injections.
Chiropractic was once considered unorthodox and simply a placebo.
Today, research has proven Chiropractic to be the treatment of
choice for many conditions. Tomorrow's research will only tell how
far reaching spinal adjustments can be.
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