Musculoskeletal Injury
Prevention
Safe Work Manitoba
January 22, 2016
Presentation Outline
• What is a MSI
• How a MSI can occur
– Back, shoulder
• How to reduce risk
– Controls
– Personal control
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. Damage can result from a single event or develop
over time. Forceful effort, repetitive motions, awkward or
sustained postures, vibration, contact stresses and
inadequate recovery times are common factors that can injure
or aggravate tissues.
• Suddenly (traumatic event)
• Over time (cumulative)
Musculoskeletal Injuries
• Good news
– Unlikely to die from a MSI
– Risk for MSI can be reduced
• Bad News
–
–
–
–
MSIs are most frequent injury
MSIs are costly
Can take a long time for recovery
Increased risk for recurrance
Musculoskeletal Injuries
• Are most frequent type of injury
MSI vs. non-MSI Injuries 2014
Surface Wounds,
Bruises
8%
Other Traumatic
Injurie
8%
Open wounds
8%
Fractures,
Dislocations
8%
Burns
2%
Sprains,
Strains,
Tears
62%
all other non-MSI
4%
MSI
62%
Musculoskeletal Injuries
• Can take a long time for recovery
Musculoskeletal Injuries
• Are costly, consider hidden costs
Musculoskeletal Injuries
• Increased risk for recurrence
Back Injuries
• So why are there so many back injuries?
– Position / posture
– Forces acting on the spine
Posture
Back Posture
• Forces acting on your back (biomechanics)
• Shear, torque, compression
Shear
Torque
Compression
Bending
Shear
Twisting / Torque
Torque
Compression
NIOSH safe lift limit – 51 lbs
764 lbs spine compression
Compression
• Many work tasks exceed
safe tolerance, especially
when combined with
bending, reaching and
twisting
Lifting
• Back disc compression, shear forces
Lifting
Back disc compression, shear forces
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
Forceful Exertions
• Lift, carry, push, pull, grip
• “Set” shoulders, core
Repetitive Motions
Definition: Continually performing the same
movement without variation
Vibration
• Whole body, hand arm
Controls
Key goals:
• Improve working postures
• Decrease stressors acting on the body that can
lead to a Musculoskeletal Injury (MSI) ie. force,
repetition, vibration
Ergonomics
Controls Examples
Controls Examples
From: Grandjean (1988)
Follow up
Postures in the Office
Sitting
• Labour market trends 1970 and 2000
• Most Canadians spend 70% of their waking day
sitting
• Sitting is linked to many negative effects
Office Chairs
• Chairs are NOT one-size
fits all
• Many women sit in chairs
that don’t fit
• A correct chair fits the
user properly
Chairs
Adjusting the Chair
1
2
3
3
4
5
6
Workstation Set Up
Ball, Kneel Chair ??
Workstation set-up
• Stressful neck, shoulder, wrist postures
Office Workstation Controls
Office Workstation Controls
Considerations
Choice
• What about exercise?
•
•
•
•
Stretching
Muscular Strength
Muscular Endurance
Cardiovascular
Exercise
• Stretching
– Goal of tissue lengthening to increase ROM
– Get up and MOVE around
Exercise
• Strength
– Maximum force, effort
• Endurance
– core
– shoulder blade region
– hips
• Exercise sensibly!!
Exercises
• Lunge
• Bird dog
• Partial curl
Exercises
• Planks
• Bridge
Exercise
• Cardio
Goals??
Review
• What MSI are
– Soft tissue / connective tissue injury
• Causes of MSIs
– Working positions
– Forces acting on the body
– Backs, shoulders
• Reducing risk
– Controls
– Exercise
Examples
Thank you for your attention
Work Smart
Work Safe