disorders (CTDs) are injuries of the musculoskeletal
system—including the joints, muscles, tendons, ligaments, nerves,
and blood vessels that are often grouped together as CTDs, Repetitive Stress
Injury (RSI), overuse syndrome,
and repetitive motion
disorders. CTDs are the largest work-related health problem in the
U.S. CTD symptoms develop from the accumulation of repeated small
injuries or stresses to our musculoskeletal system. CTD is not disease but a response to excessive or repeated
demands on our body without enough time to recover before adding more stress.
This article explains some of the concepts of CTD, what can cause CTD and how CTD causes symptoms.
Repeated small injuries add up to a larger injury or syndrome.
An injury to the body from a physical cause.
A problem with normal body functions. Syndromes are a group of signs or
symptoms—like pain, tingling or weakness—that are linked by a common
Causes of Cumulative Trauma
CTDs are usually caused by a combination of risk factors:
motions, that is making the same motion over and over like hammering a nail
using force like pulling, pushing, lifting, and gripping
posture or body positions that are unnatural resting positions
the same body position without moving or resting for long periods
compression of soft tissues
in the hand against hard edges or ridges: like tools or objects that press
against the palm
movement of body parts like swinging your arms
especially in cold conditions, like using vibrating hand tools
stress can cause muscles to tighten and restrict blood flow
enough recovery time with overuse like rest breaks or days off. This also
increases other CTD risk factors.
Common symptoms of CTDs include pain and swelling of the
affected body part. Although back injuries are not considered CTDs, they often
result from similar risk factors as CTDs. Some work and play activities have
more risk factors than others. However, it’s possible to reduce your risks and
prevent CTDs. We’ve said overuse can cause problems, but what’s really
happening? Muscle Tension + Repetitive Motion + Over Use + Incorrect or Static
Posture = CTD
To work properly, the body and its parts need a steady
blood supply, rich in oxygen and nutrients. Cutting off or reducing the blood
supply injures body tissues. When muscles are tense, they squeeze off the blood
supply which is their source of energy and fuel. Muscles can get energy without
oxygen however, the process produces lactic acid, a potent pain causing
chemical. As the pain gets worse, the muscles keep tightening to protect the
injured area—slowing down the blood supply even further. When nerves don’t
have enough blood plus the area is being squeezed by tense muscles, the nerves
begin to tingle (that pins and needles feeling) or even go numb.
Repetitive motion injuries cause tissue damage from
repeated trauma—like writing, painting or typing. Almost any activity that
produces repeated small trauma to an area of soft tissue—tendons, nerves,
muscles—can lead to CTD. Trauma happens when muscles and joints perform the
same movement over-and-over.
Using muscles and joints after they’re tired increases
the chances of injury. When muscles or tendons are overloaded or overworked they
don’t get enough rest and don’t have a chance to fully recover.
Incorrect or Static Posture
Incorrect standing and sitting postures put abnormal stress
on the body causing pain and stiffness. Our joints are made to move—even
correct posture held for too long is considered overuse.
Types of Cumulative Trauma
Tendons are fibrous tissue that connect muscles to bones.
Tendon disorders and their protective coverings, called synovial sheaths, are
the most common CTDs. CTD symptoms include:
dull ache over the inured tendon
with certain movements
pain with repeated injury without treatment
Common tendon CTDs:
Tendonitis is inflammation in the tendon caused when a muscle/tendon
is used repeatedly. With normal use, the small fibers that make up tendons get
small tears our body can easily repair. With continued overuse and without
enough time to recover, the tears aren’t able to completely heal. Tendons of
the wrists, elbows and shoulders are most often affected. Risk factors at work
or play that cause tendonitis include:
or static posture
(excessive stretching) of muscles
Without enough rest to allow injured tissues to heal
permanent damage can result.
Tenosynovitis is a general term for irritation of the tendon’s
synovial sheath caused by unnatural positions, force or pressure, along with
other CTD risk factors. Irritation stimulates the sheath to produce too much
synovial fluid. The fluid accumulates causing the sheath to swell and be
painful. Other symptoms include tenderness, cracking sounds, and often the loss
of some function in the affected body part. A poorly arranged work station,
poorly designed tools, and even bad work habits are causes tenosynovitis.
Stenosing tenosynovitis is a form of tenosynovitis. Tightening of the
tendon’s synovial sheath is caused when the surface of the tendon gets
irritated, rough, and swollen. Repetitive motions that put stress on the
tendons, such as twisting of the hand and forceful gripping, cause abnormal
thickening of the sheath and constriction of the tendons.
is from chronic friction between the two tendons in the thumb and the sheath
they share. de Quervain’s is the most recognized type of stenosing
tenosynovitis. The thumb motion is restricted by the swollen tendons. Jobs with
a high rate of de Quervain’s include buffers/grinders, sewers and cutters,
packers, and housekeepers.
Rotator cuff tendonitis, the most common shoulder tendon disorder, is often
associated with jobs that require the elbow to be in an overhead position for
long periods of time. This position puts stress on the shoulder tendons causing
tearing and swelling of the rotator cuff tendons. Repeated overhead motions
cause thickening of the tendons and the tissues of the arm sockets. This can
lead to “frozen shoulder” syndrome, which may include severe pain and the
loss of shoulder function.
Ganglionic cysts are also a tendon sheath disorder. A bump on the wrist
forms under the skin from the sheath swelling up with synovial fluid from
repetitive motion, such as prolonged typing or keyboard use.
Golfer’s elbow (medial epicondylitis) is inflammation of the epicondyle of
the humerus in the elbow caused by repeated or forceful rotation of the forearm
while bending the wrist at the same time. Epicondylitis is common in
construction jobs and assembly work.
Tennis elbow (lateral epicondylitis) is inflammation of the extensor
tendons that attach to the outside of the elbow. It’s caused by rapid over-arm
motions like throwing. Athletes aren’t the only ones affected. Most cases are
caused by job-related cumulative trauma.
happens when the tendon sheath of a finger is so swollen that the tendon becomes
locked in the sheath. The ring and middle finger are most often affected.
Trigger finger is usually caused by using tools with handles that have hard
edges or ridges, and/or repetitive forceful gripping. The pain is not usually
severe, but moving the finger causes snapping and jerky movements.
Bursitis is inflammation of the bursae, small flat sacs filled with synovial
fluid that prevent friction between tendons and muscles over bony areas like our
shoulders, elbows, and knees. A tendon that gets rough from overuse irritates
the bursa next to it causing the bursa to swell. Shoulder bursitis can make it
hard to move the shoulder and limit movement.
Pressure on the nerves pressing against hard edges or of
work surfaces, tools, or nearby bones during repeated activities can result in
cumulative trauma disorders of the nerve. The most common type of nerve CTDs:
tunnel syndrome (CTS)
is an increasingly common CTDs. CTS refers to compression of the median nerve as
it passes the carpal tunnel in the wrist. Any condition that increases the
contents or decreases the size of the carpal tunnel can compress the median
nerve. Jobs that combine high force, high repetition, awkward hand posture and
little rest—like typing, assembly work, packing, bricklaying, sewing, and
cutting—are at high risk for CTS. Symptoms of CTS include numbness, burning,
and tingling in the first 3 ½ digits. If left untreated, symptoms can become
much worse and result in the loss of grip strength, clumsiness, increased pain
at night, and possibly permanent loss of hand function.
Raynaud’s syndrome is also referred to as “vibration white finger” or
“hand-arm vibration syndrome.” This condition is caused by forceful gripping
and/or long-term use of vibrating tools like hand-held power drills, power saws,
nail guns, chipping hammers, and rotary hammer drills. Using vibrating tools in
cold temperatures increases the risk of Raynaud’s syndrome. Symptoms include
numbness and tingling in the fingers, skin that turns pale and cold, and
ultimately loss of feeling and muscle control in the fingers and hands.
Thoracic outlet syndrome (TOS)
involves the compression of nerves from the spine and blood vessels from the
heart that go to the muscles in the arm. TOS is caused by doing overhead tasks
for long periods of time. Symptoms of thoracic outlet syndrome include numbness
in the fingers, a weakened wrist pulse and feeling like one’s arm “is
Thoracic outlet syndrome is often mistaken for being carpal
Other nerve entrapment syndromes.
Repetitive motion of the upper extremities can also entrap the median, ulnar,
and radial nerves in other areas. Pronator teres syndrome involves entrapment of median nerve in the forearm. Cubital tunnel
involves entrapment of ulnar nerve from outside pressure over the cubital tunnel
at the elbow. Radial tunnel syndrome refers to entrapment of the radial nerve by the extensor
muscles of the forearm.
Treatment of Cumulative Trauma
If you’re diagnosed with a CTD, there are many
conservative, non-surgical treatments to relieve discomfort from overuse.
Splints may be recommended as an early treatment to protect and rest sore areas.
Anti-inflammatory medicines are often used along with physical therapy like ice packs, ultrasound, or electrical stimulation. Special
exercises help tissues move safely while they heal. Assess both your work and
recreational activities to figure out if they are adding to your problem. Keep
in mind that tension restricts the flow of blood causing muscles and nerves not
to get enough oxygen and nutrients, aggravating the symptoms of CTD. Resting the
injured area during work and play can relieve tension and allow recovery.
and pace yourself
be a stiff when you sit and stand
up work tasks; Cross train sports activity
or correct your work or play areas
caffeine and tobacco
Correct Posture and the Neutral Spine Position
Posture has a big role in CTDs. Slouching the spine or leading with your
head puts your body off balance causing your arms and legs to be stretched or
bent in awkward positions. The neutral spine position maintains the three
natural curves of the spine:
inward curve of the neck (cervical)
outward curve of the mid back (thoracic)
inward curve of the lower back (lumbar)
Too much curvature or straightening in either the neck or
lower back takes the spine out of its neutral position and increases the risk of
injury. To prevent injury:
of leading with your head, rotate the upper body forward at the hips.
of slouching, rotate your upper body forward at the hips.
of bending or lifting with a bent lumbar spine, rotate your upper body
forward at the hips.
Basic Guide for Sitting Posture
Sitting with a neutral alignment of the spine is also
important. Sit in a comfortable chair designed to encourage correct sitting
posture. Don’t slouch; sit back in your seat against the back of the chair.
Bending your head down strains your neck and affects nerves and arteries that go
down into your arms. Relax your shoulders with your elbows, hips and knees bent
at a right angle. Avoid pressure to the back of your knees. Keep your feet flat
on the floor or support them on a foot rest. Don’t sit still for long periods.
Staying in one position causes muscle fatigue and tension. Take breaks often;
get up and stretch.