What Causes Trigger Points?

Computer use can cause Trigger Point pain in the head, neck, back, arms, and hands.
Trigger points activate from several causes,
such as acute or chronic muscular overload due to
(though not limited to):
trauma (injury or surgery),
overuse (strain or repetitive movement),
poor posture,
holding the same position for too long,
chilling of a muscle,
and even emotional stress.
Once a Trigger Point has activated, waste products begin to accumulate.
These waste products are nerve irritants which, in turn, produce and perpetuate pain.
The pain signals can make the brain decide to turn off the muscle, as in frozen shoulder.
Why does the pain occur away from the Trigger Point?
There are different theories: one in very simple terms is analogous to peripheral neuropathy, where nerves for the toe are wired to the "toe" area of your brain, and no matter where the 3 foot long "toe" nerve is affected along its length, pain is felt in the toe. Other examples of referred pain are arm pain for heart attacks, "brain freeze" after drinking a cold liquid, scratching your ear to relieve the tickle in your throat and "phantom pain" in an amputated limb.
Trigger Points and Referred Pain - a Quick Technical Overview
From The Trigger Point Therapy Workbook, by Claire Davies

A Microscopic View
The drawing is a representation of several muscle fibers within a trigger point.
It is based on a microscopic photograph of an actual trigger point
(in this case in the belly of the SCM muscle).
This particular trigger point could cause a headache over your left eye and sometimes at the very top of your head, as well as pain at the attachments at either end (on the sternum and the mastoid process at the bottom of the cranium). Pain can even be referred to somewhere totally remote from the muscle.
Letter A is a muscle fiber in a normal resting state, neither stretched nor contracted. The distance between the short crossways lines (Z bands) within the fiber defines the length of the individual sarcomeres. Tiny sarcomeres run lengthwise in the fiber, perpendicular to the Z bands.
Letter B is a knot in a muscle fiber consisting of a mass of sarcomeres in the state of maximum continuous contraction that characterizes a trigger point. The bulbous appearance of the contraction knot indicates how that segment of the muscle fiber has drawn up and become shorter and wider. The Z bands have been drawn much closer together.
Letter C is the part of the muscle fiber that extends from the contraction knot to the muscle’s attachment (to the breastbone in this case). Note the greater distance between the Z bands, which displays how the muscle fiber is being stretched by tension within the contraction knot. These overstretched segments of muscle fiber are what cause shortness and tightness in a muscle. The perpetually stretched fibers can also contribute to weakness in the muscle.
Normally, when a muscle is working, its sarcomeres act like tiny pumps, contracting and relaxing to circulate blood through the capillaries that supply their metabolic needs. When sarcomeres in a trigger point hold their contraction, the capillaries become pinched, and blood flow essentially stops in that immediate area. This causes a build-up of the toxins of muscle metabolism which can no longer be removed from the area and transported to the kidneys, where they are normally filtered out of the blood and flushed from the body.
The Physiology of a Trigger Point (How They Work)
The part of a muscle fiber that actually does the contracting is a microscopic unit called a sarcomere. Contraction occurs in a sarcomere when its two parts come together and interlock like fingers. (Assuming that the length of biceps is 20 cm and the length of sarcomere is
2 micrometer, there are 100,000 sarcomeres along the length of a biceps muscle fiber.)
Millions of sarcomeres have to contract in your muscles to make even the smallest movement. A trigger point exists when over-stimulated sarcomeres are chemically prevented from releasing from their interlocked state.
The resulting oxygen starvation and accumulation of the waste products of metabolism irritates the trigger point. The trigger point responds to this emergency by sending out pain signals.
Referred Pain
The defining symptom of a trigger point is referred pain; that is, trigger points usually send their pain to some other site. This is an extremely misleading phenomenon and is
the reason conventional treatments for pain so often fail.
It’s a mistake to assume that the problem is at the place that hurts!
Travell and Simons’s research has shown that Trigger Points are the primary cause of pain 75% of the time and are at least a part of nearly every pain problem.
Trigger points can cause:
headaches,
neck and jaw pain,
back pain,
tennis elbow,
carpal tunnel syndrome,
thumb pain,
as well as MANY other problems.
They are the source of the pain in such joints as:
the shoulder,
wrist,
hip,
knee,
and ankle.
,
Pain from Trigger Points is often mistaken for:
arthritis,
carpal tunnel syndrome,
tendinitis,
bursitis,
or ligament injury.
Trigger Points also cause symptoms as diverse as:
dizziness,
earaches,
toothaches,
sinusitis,
nausea,
heartburn,
false heart pain,
heart arrhythmia,
genital pain,
and numbness in the hands and feet.
Even fibromyalgia may have its beginnings with myofascial trigger points.
The drawing is a representation of several muscle fibers within a trigger point.
It is based on a microscopic photograph of an actual trigger point
(in this case in the belly of the SCM muscle).
This particular trigger point could cause a headache over your left eye and sometimes at the very top of your head, as well as pain at the attachments at either end (on the sternum and the mastoid process at the bottom of the cranium). Pain can even be referred to somewhere totally remote from the muscle.
Letter A is a muscle fiber in a normal resting state, neither stretched nor contracted. The distance between the short crossways lines (Z bands) within the fiber defines the length of the individual sarcomeres. Tiny sarcomeres run lengthwise in the fiber, perpendicular to the Z bands.
Letter B is a knot in a muscle fiber consisting of a mass of sarcomeres in the state of maximum continuous contraction that characterizes a trigger point. The bulbous appearance of the contraction knot indicates how that segment of the muscle fiber has drawn up and become shorter and wider. The Z bands have been drawn much closer together.
Letter C is the part of the muscle fiber that extends from the contraction knot to the muscle’s attachment (to the breastbone in this case). Note the greater distance between the Z bands, which displays how the muscle fiber is being stretched by tension within the contraction knot. These overstretched segments of muscle fiber are what cause shortness and tightness in a muscle. The perpetually stretched fibers can also contribute to weakness in the muscle.
Normally, when a muscle is working, its sarcomeres act like tiny pumps, contracting and relaxing to circulate blood through the capillaries that supply their metabolic needs. When sarcomeres in a trigger point hold their contraction, the capillaries become pinched, and blood flow essentially stops in that immediate area. This causes a build-up of the toxins of muscle metabolism which can no longer be removed from the area and transported to the kidneys, where they are normally filtered out of the blood and flushed from the body.
The Physiology of a Trigger Point (How They Work)
The part of a muscle fiber that actually does the contracting is a microscopic unit called a sarcomere. Contraction occurs in a sarcomere when its two parts come together and interlock like fingers. (Assuming that the length of biceps is 20 cm and the length of sarcomere is
2 micrometer, there are 100,000 sarcomeres along the length of a biceps muscle fiber.)
Millions of sarcomeres have to contract in your muscles to make even the smallest movement. A trigger point exists when over-stimulated sarcomeres are chemically prevented from releasing from their interlocked state.
The resulting oxygen starvation and accumulation of the waste products of metabolism irritates the trigger point. The trigger point responds to this emergency by sending out pain signals.
Referred Pain
The defining symptom of a trigger point is referred pain; that is, trigger points usually send their pain to some other site. This is an extremely misleading phenomenon and is
the reason conventional treatments for pain so often fail.
It’s a mistake to assume that the problem is at the place that hurts!
Travell and Simons’s research has shown that Trigger Points are the primary cause of pain 75% of the time and are at least a part of nearly every pain problem.
Trigger points can cause:
headaches,
neck and jaw pain,
back pain,
tennis elbow,
carpal tunnel syndrome,
thumb pain,
as well as MANY other problems.
They are the source of the pain in such joints as:
the shoulder,
wrist,
hip,
knee,
and ankle.
,
Pain from Trigger Points is often mistaken for:
arthritis,
carpal tunnel syndrome,
tendinitis,
bursitis,
or ligament injury.
Trigger Points also cause symptoms as diverse as:
dizziness,
earaches,
toothaches,
sinusitis,
nausea,
heartburn,
false heart pain,
heart arrhythmia,
genital pain,
and numbness in the hands and feet.
Even fibromyalgia may have its beginnings with myofascial trigger points.
Over 200 spots have been identified where Trigger Points can form!

There are OVER 200 places where Trigger Points can be found!
Some basic Trigger Point information:
A trigger point is a tight area within muscle tissue that causes pain in other parts of the body. A trigger point in the back, for example, may trigger pain in the neck. The neck, now acting as a satellite trigger point, may then cause pain in the head. The pain may be sharp and intense or a dull ache. Trigger points are caused by muscle overuse or injury, and because the aches are associated with moving parts, the pain is commonly mistaken for arthritis.
Trigger Point Therapy is specifically designed to alleviate the SOURCE of the pain,by manually pumping blood through the spot with a firm, milking stroke. In this type of massage the recipient actively participates through identifying the exact location and intensity of the discomfort. (Some therapists still use a hard steady pressure on the extremely tender spot, while the patient tries to tolerate the pain by deep breathing.)
The result of Trigger Point massage is the elimination of toxins in the muscles and the release of energizing endorphins.
A significant decrease in pain is often found after just one treatment.
Trigger Points were first mapped by Dr. Janet G. Travell, President Kennedy's physician. She found that many sufferers of muscle pain had active points in predictable locations, and by treating these points, the pain would not only cease, but the cessation of the pain reflex would restore muscle function. When Senator Kennedy first consulted Dr. Travell in 1955, for muscle spasms in his low back that radiated down his leg and made walking very painful, he was questioning his ability to continue his political career. Dr. Travell's new "Trigger Point" Therapy proved very effective.
Since then Trigger Point Therapy has been used successfully by doctors and massage therapists on many patients who have suffered under the plague of chronic myofascial (muscle) pain. Many of these patients have tried surgery or drugs, but have received no real relief from their pain.
Increasingly, people in pain are looking for more natural remedies,
remedies that are less invasive than surgery,
and less dangerous than drugs, which also often have toxic side-effects.
Trigger Point Therapy is now used for myofascial pain syndromes,
which may include headache (tension and migraine),
neck, jaw, shoulder, arm, hand, back, leg, foot, and various other local or referred symptoms.
Despite the overwhelming evidence of its effectiveness in 60 years of medical journals,
Trigger Point Therapy finds few allies in the mainstream medical community,
who find it difficult to admit that a skilled massage therapist may possibly remove myofascial pain that a highly trained (and highly paid) physician has failed to resolve.
As more and more drugs are introduced to the market
(and the pharmaceutical companies adopt BIG BUSINESS attitudes),
there seems to less interest (and fewer dollars) in research to find treatments
that circumvent the need for pharmaceuticals.
However, sensible sufferers are now able to do their own research via the Internet.
Search Trigger Point Therapy for yourself.
Learn what you can.
Don't just be a medical pawn.