- Carpal tunnel syndrome is a very common problem
that causes numbness and tingling
throughout your hand and fingers.
This condition is often associated
with occupations that require
repetitive use of your hands and wrists,
like typing, sewing, or assembly work.
Now, while repetitive job movements
are one cause of carpal tunnel syndrome,
many people develop this condition
regardless of the type of work they do.
Your carpal tunnel is an opening
formed by the carpal bones of your wrist on the one side
and a ligament on the other.
And passing through the tunnel
is your median nerve.
It's this nerve that gives sensation
to your thumb, index, long, and half of your ring finger.
It also helps to control movements of your thumb.
In addition to your median nerve,
your flexor tendons pass through that carpal tunnel.
These are the tendons that are responsible
for movement of your fingers, thumb, and hand,
like when you grasp an object.
Your flexor tendons are surrounded
by a slippery covering
allowing the tendons to glide smoothly.
The carpal tunnel can't expand.
So any problems that cause abnormal pressure in the tunnel
can produce carpal tunnel syndrome.
Abnormal pressure is caused by
making the tunnel smaller
or by increasing the stuff that's in the tunnel
while the tunnel stays the same size,
or an increase in the pressure itself
within the carpal tunnel,
which in turn reduces the blood flow to the nerve
and causes a loss in nerve function.
Today we're going to talk about
the anatomy or parts list of your wrist
and how it contributes to developing numbness and tingling,
what activities you may be doing that increase your risk
of developing carpal tunnel,
what your symptoms feel like
and how we evaluate a carpal tunnel syndrome,
what are the latest treatment options
for relieving your symptoms,
what you can do right now to prevent
or minimize your risk of developing carpal tunnel syndrome.
Let's look at the parts list.
Well, first of all, there's this electric cable
called the median nerve
that runs from your neck
down the middle of your arm,
has to go through the wrist
and into your hand
because it needs to innervate
or produce sensation
for your thumb, your second,
third, and part of your fourth fingers.
So here comes this nerve
that's coming down your arm
and it's on its way to the hand.
In order to get to the hand
it runs through a little tunnel
that sits right here at the wrist.
So here is the tunnel.
I'm going to just draw it as a little tube.
This is the top of the tube.
And this is the entrance to the tube.
And this is the exit of the tube.
So here comes the nerve.
It goes through the tunnel.
It comes out the other side.
And then it splits into branches.
There's a cable that goes to the thumb.
There's a cable that goes to the second finger.
There's a cable that goes to your third finger.
And there's a cable that goes to the inner side
of your fourth finger.
The problem develops
when this cable gets pinched in this tunnel.
One of the most common ways for it
to get pinched and inflammed
is when the tunnel gets thick
and the room in the tunnel is reduced.
So let's take that tunnel now and draw it here
and show you what I mean.
Here's the tunnel.
Here's the cable that is the median nerve
going through the tunnel.
That's a normal tunnel.
When the tunnel thickens,
it gets thick and it gets swollen,
it looks something like this.
Swollen tunnel.
And the hole through the tunnel
gets smaller like this.
As a result, the nerve that's coming through the tunnel
doesn't have much room.
And as a result it gets pinched,
irritated, and itself often swollen.
This causes pain
and the numbness in your fingers.
When we do a carpal tunnel release,
what we do is simply open the top of this tunnel.
As we open it, it's in so much tension
that it just splits apart
allowing the pressure to decrease on the nerve.
In other words, it looks something like this.
So we've made a split
on top of the tunnel like this.
And as a result of that, one end
splits up this way.
The other end
splits down this way.
And the nerve inside the tunnel
that's been under pressure,
painful and angry,
now no longer has any pressure on it.
And you go from having
a lot of pain
to having much less and no pain.