Transcript Hazard Identification and Risk Control

Musculoskeletal Injury
Prevention
Presented by Roland Reenders
Safe Work Manitoba
January 25, 2017
Presentation Outline
• MSI Hazards
• Costs
• How an MSI can occur
– Back injuries, shoulders
• How to reduce risk
– Controls
– Personal control
5 Hazard Categories
•
•
•
•
•
Physical
Biological
Chemical and mineral
Psychosocial
Musculoskeletal
MSI Definition
A musculoskeletal injury (MSI) is soft tissue
damage or aggravation in the musculoskeletal
system caused when demands exceed the
tolerance of connective or related soft tissues
such as muscles, tendons, ligaments, nerves,
discs and joints.
Musculoskeletal Injuries
• Are costly, consider hidden costs
Anatomy of an MSI
• Muscles, ligaments, intervertebral discs and
other connective tissues have limits on how
much they can be compressed, twisted or
pulled before they begin to fail.
• Injury process:
– high loads, short duration (suddenly)
– low loads repeated or sustained
(cumulative)
Ligaments
• Ligaments are like strong, stiff strings that
connect your bones together.
• If a joint is forced beyond its normal range of
motion, the ligament may stretch or tear
(sprain).
Muscles
• Muscles, via the tendon, connect bones to
bones and cause movement.
• A muscle used beyond its tolerance can
develop a tear (strain)
Discs
• An intervertebral disc challenged beyond its
tolerance can bulge or tear (herniate)
MSIs – Body Parts
1
2
3
4
5
Back – 47%
Neck & shoulders – 15%
Legs & feet – 14%
Arms & hands – 12%
Other & multiple – 11%
Almost as many back injuries as
other injuries combined!
Back Injuries
• So why are there so many back injuries?
– Working Positions
• Forces acting on the spine
• Muscle and ligament stress
Posture
Neck loading
Source: Kenneth k. Hansraj MD Chief of Spine Surgery New York Spine Surgery & Rehabilitation Medicine New York: Assessment of Stresses in the
Cervical Spine Caused by Posture and Position of the Head:
Spine
• 33 small block-like bones called vertebrae
arranged in slight “S” curve.
• Flexible discs between each vertebrae to
allow movement.
• Discs can become damaged:
– Bending/shear
– Twisting/torque
– Compression
Bending
Back disc wedging + shear forces
Shear
Twisting / Torque
Torque
Compression
• NIOSH safe lift limit – 51
lbs; 764 lbs spine
compression
• Many work tasks exceed
safe tolerance, especially
when combined with
bending, reaching and
Compression
twisting
Time, Genetics
Shoulder Postures
• Reaching – increases shoulder stress
Shoulder Postures
• Reaching
Sitting Posture
• Sitting adds stress to the spine
and supporting structures
• Increased disc pressure
• Ab muscles disengage, less
spine support
• Muscle imbalances, fatigue
• Avoid prolonged sitting!
Stand
Sit
Spine Loading
Sitting
• Labour market trends 1970 and 2000
• Most Canadians spend 70% of their waking
day sitting
• Prolonged sitting is linked to many negative
effects
Manual Materials Handling
Controls for MSI Hazards
• If an MSI hazard cannot be eliminated, there
are four main measures that will reduce risk:
1.
2.
3.
4.
Engineering controls
Safe work procedures (SWPs)
Appropriate work schedules
Personal protective equipment (PPE)
• Ergonomics – “fit the job to the worker”
1. Engineering Controls
• Physical changes made to the workstation,
equipment, tools and materials
• Improve the “fit” of the job to the worker
– work in more neutral postures
– decrease physical effort when performing tasks
– decrease forces acting on the body
– be more comfortable
Controls Examples
From: Grandjean (1988)
Controls Examples
Controls Examples
Chairs
Chairs
• Chairs are NOT one-size
fits all
• Many women sit in
chairs that don’t fit
• A correct chair fits the
user properly
Controls Examples
• Office – improve postures
Controls Examples
• Office – improve postures
Ball, Kneel Chair ??
2. Safe Work Procedures
• How to perform a job or job task safely
– equipment or devices to be used
– safe body positions or movements
Safe work procedures 2.1.1
• (a)develop safe work procedures for the work;
• (b)train workers in the safe work procedures in a manner that
ensures workers are able to apply the training provided;
• (c)ensure that workers comply with those SWPs.
Retention
Postures – Lifting
3. Work Schedules
• Modify work schedules to reduce the
frequency or duration of an MSI hazard
– Job rotation
– Task scheduling
– Micro breaks
– Task variation
4. PPE – What Works?
Follow Up on MSI Controls
• Following up will ensure that:
– changes to work processes are being followed
– changes implemented are effective
– job tasks are being performed as outlined in safe
work procedures
– training is consistent with the safe work procedure
• Who should follow up?
Exercise
• Exercise can reduce your risk for injury
Exercise
• Endurance
– core
– shoulder blade region
– hips
Exercise
Symmetry
• Poor symmetry (imbalances) can lead to
symptoms over time
Exercise
• Stretch breaks
Exercise
• Exercise sensibly
Goals??
Hazard Controls
Effectiveness
Personal control
Equipment or Engineering
Job organization
Personal protective
equipment
Bodymechanics/fitness
Summary
• MSI defined
• Costs
• How MSIs occur
– Demands on soft tissues
– Back, shoulders
• How to reduce risk
– Controls
• Engineered, SWPs, work schedules, PPE
– Exercise
Thank you for your attention
Today’s presentation is an overview of the
Musculoskeletal Injury Prevention
full-day course.
Consider attending the full-day session for this and
other courses by registering on-line at
www.safemanitoba.com
Roles
Workplace Safety & Health Branch