When
viewing the hand in the functional, palm-down position,
the carpal tunnel is a narrow passageway,
consisting of the transverse carpal ligament positioned
on the front of the wrist and two rows of four carpal
bones positioned on the back of the hand, making the
carpal tunnel "ceiling". Within the small carpal tunnel
runs the nine flexor tendons and the median nerve. If
anything takes up extra room in the canal (e.g. inflammatory
swelling, injury, increased size of tendons, collapsing
tunnel, etc.), the nerve in the canal becomes compressed
or 'pinched', leading to carpal tunnel syndrome symptoms.
HOW COMMON IS CARPAL TUNNEL SYNDROME? Carpal
tunnel syndrome (CTS) is a common condition, with an
occurrence rate of about 3% annually in the general population.
Carpal tunnel syndrome is more common in women than men
with the belief of wrist size as one of the predominating
factors. The average age of Carpal tunnel syndrome sufferers
is between 40-50 years. Although 3% of the population does
not sound like much, it is about 9 million people affected
each year!
WHAT CAUSES CARPAL
TUNNEL SYNDROME? The
cause of carpal tunnel syndrome is caused by compression
of the median nerve, and the median nerve is compressed
due to weak extensor muscles not stabilizing he carpal
bones (ceiling of carpal tunnel) and cause it to collapse
inward, decreasing the size of the carpal tunnel. As the
carpal tunnel collapses and the tunnel narrows, there is
increased friction, resulting in irritation and swelling
of the flexor tendons and median nerve. As the tendons
swell, the compress the median nerve. If the extensor tendons
are strengthened, they stabilize the carpal bones and keep
them from collapsing into the carpal tunnel. Because of
this, the tunnel stays in the open position and there is
no additional pressure on the tendons and does not result
in irritation and swelling and the compression of the median
nerve. It is really a musculoskeletal disorder caused by
a basic muscle imbalance.
Although muscle imbalance is the main cause of carpal
tunnel syndrome, a variety of carpal tunnel syndrome risk
factors may contribute to the development of the condition:
- Wrist Injury
- Diabetes Mellitus
- Thyroid Disease
- Rheumatoid Arthritis and other
Joint Disorders
- Pregnancy
- Menopause
- Acromegaly
- Overuse, work situations requiring repetitive
or static wrist and finer flexion
- Adema / Fluid Retention
- Systemic inflammation
- End-stage renal
disease and dialysis