Transcript Repetitive Strain Injuries - Windsor Occupational Health

Musculoskeletal disorders
OH&S presentation
by
Dr. Roy Bertrus Perera
WOHIS Volunteer
WINDSOR OCCUPATIONAL HEALTH INFORMATION SERVICE
Introduction
Definition
Musculoskeletal disorders (MSDs) are
injuries of the muscles, nerves, tendons,
ligaments, joints, cartilage, or spinal discs.
MSDs are not typically the result of any
acute event (such as a slip, trip, or fall) but
reflect a more gradual or chronic development.
Other names used to describe MSDs
Repetitive strain injuries
 Cumulative trauma disorders
 Overuse syndrome
 Regional musculoskeletal disorders
 Repetitive motion injuries
 Soft tissue disorders

Causation
Musculoskeletal disorders
are mainly caused by :

Repeated use of force

Repetitive movements

Working in unnatural body
positions or awkward postures
Force
Force is the amount of effort exerted by your
muscles.
The MSD risk associated with force
increases as:
 the amount of force required increases
 the posture used gets more awkward
 the number and/or speed of repetitions
increases
 the length of time the force is exerted
between breaks increases
Activities that often involve high force
requirements include:
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lifting, lowering and carrying
pushing or pulling, and
gripping and manipulating objects
Repetition
The MSD risk associated with repetition
increases as:
 the number or speed of actions required
increases
 the muscles being used must exert higher levels
of force
 the joints of the body move farther away from
the neutral position
 the length of time the task is done without a
break increases
Awkward Postures
For most joints, good posture is near the middle of
the full range of motion. This is called the
“neutral" posture.
The risk associated with awkward postures
increases as:
 the joints move farther away from a neutral
posture
 the muscles exert higher levels of force
 the number of times the posture is adopted
increases
 the length of time the posture is held increases
EXAMPLES OF TASKS THAT REQUIRE AWKWARD
POSTURES:
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leaning sideways to reach into a low drawer
while sitting
bending down to work at a low level
keyboarding on a desk that is too high
reaching over your head (e.g., when painting a
ceiling)
reaching for objects behind your back
bending your wrist when moving objects or
keyboarding
bending your neck down (e.g., looking at small
components in poor light)
twisting your neck to view documents or the
computer monitor
Secondary factors
Use of badly designed tools and
machineries
 Increased workload
 Working in cold or hot environments
 Poor job training

MSDs develop gradually

MSDs do not happen as a result of a
single accident or injury; rather, they
develop gradually as a result of repeated
trauma. Excessive stretching of muscles
and tendons can cause injuries that only
last a short time; but repeated episodes of
stretching causing tissue inflammation can
lead to long-lasting injury or MSDs.
Presentation
MSDs include three types of
injuries:
● muscle injury
● tendon injury
● nerve injury
Muscle Injury
When muscles contract, they use chemical
energy from sugar and produce by-products
such as lactic acid which are removed by the
blood. A muscle contraction that lasts a long
time reduces the blood flow.
Consequently, the substances produced by the
muscles are not removed fast enough, and they
accumulate. The accumulation of these
substances irritates muscles and causes pain.
The severity of the pain depends on the duration
of the muscle contractions and the amount of
time between activities for the muscles to get rid
of those irritating substances.
Tendon Injury

Tendons consist of numerous bundles of fibres
that attach muscles to bones. Tendon disorders
related to repetitive or frequent work activities
and awkward postures occur in two major
categories:
1. Tendons with sheaths, found mainly in the hand and wrist
2. Tendons without sheaths, generally found around the shoulder,
elbow, and forearm
The tendons of the hand are encased in sheaths
through which the tendon slides.
Nerve Injury

Nerves carry signals from the brain to control
activities of muscles. They also carry information
about temperature, pain and touch from the
body to the brain, and control bodily functions
such as sweating and salivation. Nerves are
surrounded by muscles, tendons, and ligaments.
With repetitive motions and awkward postures,
the tissues surrounding nerves become swollen,
and squeeze or compress nerves. Compression
of a nerve causes muscle weakness, sensations
of "pins and needles" and numbness. Dryness of
skin, and poor circulation to the extremities,
may also occur.
Clinical symptoms of MSDs
• Discomfort continues
• Sleep disturbances
• Continuous general
weakness
• Limitation of work
• Restrictions of movements
• Sleep disturbances
• Other physical &
psychological
problems
• Pain
• Tiredness
• Numbness
• Tingling
• Discomfort
• Stiffness in joints
• Weakness
• Swelling
• Burning
• Loss of functions
Joints & Tendons
 Bursitis
 Tendinitis
 Tenosynovitis
Wrist & Hand
 Carpel tunnel Syndrome
 Trigger finger
 Reynaud's syndrome
 Ganglion
Elbow
 Epicondylitis
Neck & Shoulder
 Rotator cuff tendinitis
 Thoracic outlet syndrome
Back
 Degenerative disk disease
 Herniated disc
 Chronic back pain
Legs & Feet
 Plantar fasciitis
Other
 Osteoarthritis
Conditions
associated
with MSDs
Scope of the problem
WSIB received the following lost time
claims in 2008

Sprains & strains
Tendonitis
Herniated or slipped Inter vertebral disc
Carpal tunnel syndrome
Epicondylitis
Bursitis
Rotator cuff tear
Tenosynovitis
Sciatica
Ganglion
Capsulitis
Synovitis
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All other MSDs,work related diseases & injuries
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TOTAL
39513
1675
832
687
582
182
260
153
137
39
16
07
34173
78256
50.5%
2.1%
1.1%
0.9%
0.7%
0.2%
0.3%
0.2%
0.2%
0.0%
0.0%
0.0%
43.8%
100.0%
Diagnosis & treatment
Evaluation & Diagnosis

The evaluation of MSDs includes identifying workplace
risks. Evaluation begins with a discussion of the person's
employment and requires a detailed description of all the
processes involved in a typical workday. Consideration is
given to the frequency, intensity, duration, and
regularity of each task performed at work.

Diagnosis of MSDs is confirmed by performing laboratory
and electronic tests that determine nerve or muscle
damage. One such test, electroneuromyography
(ENMG), encompasses two areas: electromyography
(EMG) and nerve conduction velocity (NCV). Magnetic
resonance imaging (MRI), an alternative to x-rays,
provides images of tendons, ligaments, and muscles and
improves the quality of the diagnostic information.
Treatment of MSDs
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The treatment of MSDs involves several
approaches including the following:
Rest
Application of heat or cold
Exercise, massage
Splints, bandages
Physiotherapy
Medication
Surgery
Prevention
MSDs Prevention
The essential keys to prevent MSDs in the
workplace are:
■ management commitment and support
■ a documented MSD prevention process
that is communicated to all workplace
parties
■ worker participation in the prevention
process
■ training on MSD prevention for all
workplace parties
Steps in the MSD prevention framework
Recognize MSD hazards and related concerns
No
Do MSD Hazards or Related Concerns
exists ?
Yes
Conduct an MSD risk assessment
Increased Risk
of MSD and/or Other Indicators
that Controls are Required ?
Yes
Choose and implement MSD hazard controls
Follow up on and evaluate success of implemented controls
Communicate results and acknowledge success
No
Employers and managers should:
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incorporate MSD prevention into their health and safety policy and
program
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review the health and safety program to include or strengthen MSD
prevention activities
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make sure that workers and JHSC members or the H&S rep are
trained on how to recognize, assess and eliminate or control MSD
hazards
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ensure that supervisors know what to do if they recognize MSD
hazards or if a worker raises a concern
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ensure that MSD hazards related to poor design of tools, equipment,
workstations or work practices are identified and any associated
risks are controlled
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make sure that new equipment is designed and installed to reduce
exposure to MSD hazards

ensure that workers have the equipment and training they need to
reduce their exposure to MSD hazards
Supervisors should:
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ensure that everyone under their supervision is aware of MSD
hazards on the job and is trained to do his or her job safely

look for MSD hazards during workplace inspections, job task
analyses and discussions with workers, and when reviewing injury
reports
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reinforce proper working techniques and use of equipment and
personal protective equipment (PPE)
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encourage and support workers taking scheduled breaks
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check that workers have adjusted their workstations to suit
themselves and their work, and provide help as needed
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support workers when they have questions or concerns and be
aware of MSD warning signs and indicators
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take action on reported MSD hazards and concerns and follow up
with workers
Workers should:
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report MSD hazards and concerns to their supervisors
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take scheduled breaks and take advantage of opportunities to change
postures or relax muscles
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move around and occasionally change positions
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go to their supervisors with questions and concerns or to ask for additional
training
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offer suggestions to improve working conditions to their supervisor, health
and safety representative or the JHSC
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be aware of symptoms of MSDs and report them early if they occur

ensure that they understand the information and instructions provided
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use proper working techniques

use the equipment and tools provided to reduce exposure to MSD hazards

know how to make adjustments to the workstation to suit themselves and
the work they do, and to ask for help as needed
References:
London Occupational Safety & Health
Information Service, When Aches Become
Injuries( Second edition), 1998
 Occupational Health and Safety Council of
Ontario, Resource Manual for the MSD
prevention Guideline for Ontario, 2007
 http://www.wsib.on.ca/wsib/wsibsite.nsf/Public/
CurrentStatistics
 http://www.ccohs.ca/oshanswers/diseases/rmirsi
.html

For more information,
please contact
WOHIS 519-254-5157
or
For a free workplace assessment
please contact OHCOW (Windsor) Occupational Health
Clinics for Ontario Workers, Inc.
519-973-4800
Remember, you have the right
to a safe & healthy workplace!
Thank you