Document describing carpal tunnel syndrome. A class assignment at Colorado Technical University Online.

1. Running head: CARPAL TUNNEL SYNDROME 1
Carpal Tunnel Syndrome
Michelle Stahl
CTU Online
Biology
143
Professor Karim
December 14, 2011

2. CARPAL TUNNEL SYNDROME 2
Abstract
This article discusses the definition of carpal tunnel syndrome, the anatomy of the arm,
and treatment of carpal tunnel syndrome. The anatomy discussed is skeletal, muscular, and a
brief mention of the brachial plexus and median nerves. It includes images from A&P revealed
3.0. I also go over prevention and carpal tunnel release surgery.

3. CARPAL TUNNEL SYNDROME 3
Carpal Tunnel Syndrome
What is Carpal Tunnel Syndrome?Carpal Tunnel Syndrome affects the median nerve
of the brachial plexus as it runs through the carpal tunnel in the wrist. The inflammation of the
nerve and pressure on it by the transverse carpal ligament can cause pain, weakness, or
numbness in the thumb and the first three fingers of the affected hand. Advanced cases of carpal
tunnel syndrome can cause atrophy of the muscles of the thumb. The condition occurs with
repeated trauma to wrists from repetitive movements (flexion) of the wrist(A.D.A.M, 2011).
Anatomy: The brachial plexuses are the anterior branches of the lower four cervical
nerves and the first thoracic nerve (Shier, Butler, & Lewis, 2010). This plexus is deep within the
shoulders between the neck and armpits. The median nerve supplies the muscles of the forearms,
and the skin of the hands with movement and sensation. Pictured below is the brachial
plexus(APrevealed Version 3.0, 2011).

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A picture of the median nerve below, notice how it supplies feeling to the thumb and first
three fingers of the hand(APrevealed Version 3.0, 2011).
The upper arm is attached at the pectoral girdle comprised of the scapula and clavicle that
articulate with the Humerus to form the upper arm. The Humerus articulates distally with the
radius and ulna, forming a hinge joint. The radius and ulna then articulate distally with eight
carpal bones, in two rows of four bones each. It is through these carpal bones that the carpal
tunnel carries the median nerve through to innervate the muscles of the hand. Also traveling
through this tunnel is the transverse carpal ligament, and all the associated blood vessels
including arteries and veins. The lowest row of the carpal bones articulate with the metacarpal
bones of the hand, of which there are five. These metacarpals make up the palm of your hand.
The metacarpals articulate distally with the phalanges, there are proximal, median, and distal
phalanges for each finger except the thumb. In the thumb there are distal and proximal

5. CARPAL TUNNEL SYNDROME 5
phalanges. It is important to note that the carpal tunnel is just that, a tunnel that runs through the
carpal bones of the wrist. This tunnel is very narrow, so any swelling of the tissue there puts
pressure on the median nerve (APrevealed Version 3.0, 2011).
The muscles of the arm include the coracobrachialis, pectoralis major which flex
the arm. The Teres major and Latissimus dorsi muscles make up the extensor muscles that
extend the arm. The abductor muscles are the Supraspinatus and Deltoid muscles that abduct the
arm and Subscapularis, Infraspinatus, and Teres minor muscles that rotate the arm.
The muscles of the forearm include: Biceps brachii, brachialis, and brachioradialis that
are responsible for flexing the forearm. The Triceps brachii is responsible for extending the
forearm. Finally the Supinator, pronator teres, and pronator quadratus muscles rotate the forearm.
The muscles of the hand include the flexors: flexor carpi radialis, flexor carpi ulanaris,
palmarislongus, and flexordigitorumsuperficialis. The extensors are comprised of: extensor carpi

6. CARPAL TUNNEL SYNDROME 6
radialis longus, extensor carpi radialis brevis, extensor carpi ulnaris, and extensor digitorium.
The muscles of the hand move the wrist and the fingers and are most impacted by carpal tunnel
syndrome.
Causes of Carpal Tunnel Syndrome: As mentioned earlier repetitive motions can cause
trauma to the carpal tunnel inside the wrist. Repetitive flexing of the wrist can occur from typing,
computer work, painting, massage work, using improperly sized hand tools, and bad posture
when doing office work.
Symptoms and Diagnosisof Carpal Tunnel Syndrome: Pain or numbness in the thumb
and first three fingers of the hand, particularly when bending or flexing the wrist. The pain or
numbness seems to worsen at night. With prolonged cases atrophy of the muscles in the thumb
can be seen. Your doctor will do a series of tests to determine if you have carpal tunnel
syndrome. He will flex your wrist for 60 seconds and then check for numbness or pain this is
referred to as Phalen’s sign. He or she may also tap on the median nerve in the forearm; if this
produces pain then this is referred to as Tinel’s sign. Other diagnostic tests such as nerve
conduction or electromyography may also be ordered to determine the extent of the damage to
the median nerve. X-rays may be done to rule out arthritis, or a fracture.
Treatment Options: The patient will be given a splint to rest the wrist and prevent
further trauma for several weeks. This is to relieve the pressure on the median nerve. You may
also be given anti-inflammatories such as ibuprofen, or Aleve. Your doctor may also give you a
corticosteroid injection to ease pain. You may have to change the way you do work, to avoid
further damage. You may need to change your work environment, with furniture or specialized
tools to avoid straining your wrist and aggravating your symptoms. Proper posture when typing
for example can help greatly. You may also need to do physical therapy and take regular short

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breaks to stretch your wrists and fingers when doing prolonged repetitive tasks such as typing.
As a final resort your doctor may suggest Carpal Tunnel release surgery.
Carpal Tunnel Release: In carpal tunnel release surgery a small incision is made in the
palm of the hand near the wrist. This allows the surgeon to access the carpal tunnel and cut some
of the traverse carpal ligament to relieve pressure on the median nerve. Sometimes other tissue
may be removed to make more room. The incision is then sutured closed and kept dry until it is
healed. During this time you may have to do finger exercises to increase circulation to the site
(F.A. Davis Company [F.A. Davis], 2005, p. 349). Once pressure from the nerve is released, the
nerve should stop hurting depending on how long it has been pressed upon. This should enable
the nerve to function normally as it once did, restoring feeling and movement; however ifdamage
has been prolonged, and then the damage may be permanent. With permanent damage the patient
may have pain or weakness in the affected hand permanently.
Prevention: Always check your posture when sitting or working. Improper posture can
cause additional strain on your joints including your wrists. Try to take regular breaks when
doing activities that cause you to bend and flex your wrists repeatedly, such as typing or
gripping. Try stretching your arms, hands and fingers to improve blood flow. Use ergonomic
office furniture and computer supplies to lessen strain. Make sure your furniture including your
keyboard and monitor is adjusted for your height and comfort. Eat a nutritious diet, and get
plenty of exercise to improve your flexibility, and strength. Finally make sure hand tools are
being used properly and are sized for your hand to avoid stressing the wrist.

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References
A.D.A.M (2011).Carpal Tunnel Syndrome.In D. Zieve, & D. R. Eltz (Eds.), U.S. National
Libarary of Medicine (Loc. para 1 - 11). Retrieved from
http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001469/
Anatomy & Physiology Revealed 3.0 (Version 3.0) [Computer software]. (2011). Retrieved from
http://www.mhhe.com/sem/apr3/
David, S., Jackie, B., & Lewis, R. (2010).Hole’s Human Anatomy & Physiology (12 ed.). New
York, NY: McGraw-Hill.
F.A. Davis Company. (2005). Carpal tunnel syndrome. In D. Venes, A. Bidderman, E. Adler, B.
G. Fenton, & A. D. Enright (Eds.), Taber’s Cyclopedic Medical Dictionary (20, pp. 348 -
349). Philadelphia, PA: F.A. Davis Company.