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Carpal Tunnel Symptoms: Wrist/Hand Pain and Numbness

Carpal tunnel symptoms are numbness in your thumb and first two fingers, and pain in your wrist and hand. The pain and numbness will lead you to rub your wrist and hand to bring circulation back into your hand.

A basic understanding of structures that press on the nerves to your hand will help you eliminate pain and numbness.

The Structures that Cause Carpal Tunnel Symptoms:

1. The Brachial Plexus

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The brachial plexus is a bundle of nerves that come out of your spinal cord at the base of your neck.

These nerves ultimately separate and innervate your shoulders, upper chest, back, arm, and hand.

An impingement on any of the nerve fibers will cause carpal tunnel symptoms: pain or numbness to the area that is served by that fiber.

2. The Median Nerve

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Your median nerve begins within a bundle of nerves called the Brachial Plexus. The Brachial Plexus are nerve fibers at the base of the front of your neck.  The specific nerve becomes the Median Nerve when it passes under a small bone in the top of your shoulder. The small bone is a part of your scapula (shoulder blade) and is called the Coracoid Process,

The nerve passes under muscles and bones as it goes down your body to your thumb and first two fingers.

Hand/wrist, pain & numbness are caused by pressure from any of these structures onto the median nerve.

3. The Anterior Scalenes

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The anterior scalenes are muscles in the front of your neck. They originate on your cervical vertebrae (C3-6) and insert into your 1st and 2nd ribs.

When your scalenes contract you move your head forward or to the side. When your scalenes are shortened by repetitive movements that cause spasms, they press into your brachial plexus.

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Referred Pain Area of a Brachial Plexus Impingement

The pressure on the brachial plexus can cause carpal tunnel symptoms of burning, tingling, and numbness. You feel the discomfort into your chest, posterior neck, mid-back, shoulder, arm and hand.

4. Pectoralis Minor

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As the nerves go across the top of the shoulder, they divide into the Median, Ulnar and Radial nerves. The division happens just under the insertion point of the Pectoralis Minor muscle.

As the muscle pulls on the bone it puts pressure onto the three nerves, especially on the median nerve.  This is the nerve that is responsible for the carpal tunnel symptoms of numbness and tingling in the thumb and first two fingers. Pressure may even go to the ulnar and radial nerves if the muscle tendon is pressing hard enough. This is especially evident when your arm is held up for an extended amount of time.

5. Biceps


The Biceps (short head) also originates on the Coracoid Process.  Every time you bend your arm you are putting pressure on your shoulder joint and the coracoid process.

Your muscle shortens when you hold your arm bent for extended periods of time. As you straighten your arm, the now-shorter biceps will pull on the bone. The bone then presses into the three nerves, especially on the median nerve.

The pressure on the three nerves may cause numbness and tingling to your wrist and all of your fingers.

Muscles and Tendons that Directly Impact the Median Nerve Within the Carpal Tunnel and Cause Carpal Tunnel Symptoms:


Your carpal tunnel is at the junction of your wrist between your forearm and hand.  As you look at the graphic, the gray area is your carpal tunnel.  All eight of your flexor tendons, and your median nerve, pass through this small tunnel.

Your extensor muscle tendons are the small circles on the outside of the graphic. Each extensor tendon inserts into the bones that form the back of your hand, called the carpal bones.

The following muscles have a direct impact on your carpal tunnel:


6. Flexors


The eight Flexor Muscles (colored in red) originate at your inner elbow and form the underside of your forearm. The tendons pass through your carpal tunnel, along with your median nerve. Your flexor muscles enable you to curl your hand into a fist, and to bend your wrist. The repetitive nature of these muscle can cause them to shorten due to a phenomenon called Muscle Memory. As the muscles tighten they cause the tendons to become taut.

The impact of the taut flexor tendons to carpal tunnel symptoms was proven in a research paper written in 1977.

Spasms in your flexor muscles will also cause a condition called Trigger Finger because your fingers won’t open fully.

7. Extensors


Your extensor muscles originate at your elbow joint and form the top of your forearm. The tendons insert into the bones of the back of your hand and into your fingertips. up.When these muscles contract you open your clenched hand &/or bend your wrist so you can lift your hand up.

Your carpal bones are strained as the muscles are causing a misalignment as they pull on the insertion points.  This strain causes pressure on your median nerve, which causes tingling and numbness in your thumb and first two fingers.

Your extensor muscles are rarely considered by the professionals searching for the cause of carpal tunnel symptoms. However, they are frequently involved in the symptoms because of the way they alter the dimension of the carpal tunnel.

8.Opponens Pollicis


Carpal tunnel symptoms are caused by the flexor retinaculum pressing on the median nerve as it passes through the carpal tunnel. Your Opponens Pollicis muscle originates on the flexor retinaculum ligament and inserts into the base of your thumb.

You use your thumb muscle millions of times every day. The repetitive use commonly shortens the muscle and strains the thumb joint.The strain will be felt when you try to open your had fully from the clenched position. When the opponens pollicis muscle is tight you may also have the symptoms of arthritis in your thumb.

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