2. Health and safety
Accidents
Unsafe behavior
Unsafe systems
Everyday accidents
Slipping, tripping & falling
Machinery – safety distance
Ergonomic injuries
Lifting and handling injuries
Work-related upper limb disorders
Musculoskeletal pain resulting from unsatisfactory
working posture
Loisa Sessman, Halmstad University
3. Ergonomic injuries
Mismatch
Over-use injury
“Creep” effect (fatigue)
Mechanical strength
Co-ordination
Range of motion
Foreseeable, injuries can be predicted!
Back pain
Occupational
Personal risk factors
Loisa Sessman, Halmstad University
4. Lifting and handling
Lift close to the body
Reduce the lever arm
Control
Symmetric
Avoid asymmetric lifting
Foot placement
Weight limits
Different limits for different countries
Sweden, 7 kg = ok, 7-25 kg = risky 25 kg = very
high risk
Loisa Sessman, Halmstad University
5. Work-related upper limb disorders
WRULD
Umbrella term for CTD and RSI
Repetitive strain injury (RSI)
Cumulative trauma disorders CTD
Mainly affects:
Industrial assembly workers
Workers at supermarket checkouts
Musicians
Keyboard users
Loisa Sessman, Halmstad University
6. RSI & CTD
Often occurs in the upper limb
Injuries in nerves, muscles, ligaments, tendons
and joints etc
Causes pain
Related to work intensity and duration
Weeks, months or years
Diffuse symptoms
Often unreported
Several reasons (work and/or leisure time)
Loisa Sessman, Halmstad University
7. RSI & CTD
CTD & RSI increases
Increased awareness and reporting
Increased specialization
Computer work
Mental stress
Posture
Force
Repetition
Loisa Sessman, Halmstad University
8. Postures
Extreme flexion and extension, ulnar and radial
deviation of the hand
Carpal Tunnel Syndrome
Tenosynovitis
Extreme flexion of the elbow
Cubital Tunnel Syndrome
Extreme rotation of the forearm
Epicondylitis
Work above shoulder level
Thoracic Outlet Syndrome
Loisa Sessman, Halmstad University
9. Carpal Tunnel Syndrome
Results from high repetitive work in extreme
positions, often in combinations with force
Median nerve get squeezed
Numbness, tingling pain and clumsiness
Loisa Sessman, Halmstad University
10. Tenosynovitis
Tendon sheath swells
Occurs at wrists and ankles where tendons cross
ligaments
Pain, burning sensation and swelling
Loisa Sessman, Halmstad University
11. Cubital Tunnel Syndrome
Compression of the ulnar nerve in the elbow
Tingling and numbness occurs at the little finger
and the ulnar side of the ring finger
Causes when resting the elbow on a hard surface
or sharp edge
Loisa Sessman, Halmstad University
12. Epicondylitis
Lateral epicondylitis – De
Quervain's disease (tennis elbow) Lateral epicondylitis
Injuries and pain resulting from
work with computer mouse
Causes of high repetitive finger
Medial
movements in combination with epicondylitis
static work Tendon
The symptoms: pain in the forearm Muscle
and weakness in the hand and
wrist
Medial epicondylitis – golfer’s arm http://www.orthoactiv.de/index.php?open=peripherenerven
Similar to tennis elbow
Affects the medial epicondyle of
the humerus
Loisa Sessman, Halmstad University
13. Tendonitis or tendinitis
Inflammation of a tendon
Pain, swelling, burning sensation
Tendonitis or bursitis at the rotator cuff
Unnatural static positions
Heavy work
External load
Repetitive arm movements
Work above shoulder height
Loisa Sessman, Halmstad University
14. Thoracic outlet syndrome
Compression of three nerves of the arm and blood
vessels
Numbness
Difficult to move the arm
Loisa Sessman, Halmstad University
15. Contact stress
Mechanical stress (contact stress) on nerves and
tendons
Handhold objects with sharp edges and hard objects
Vibrating tools - Raynauds syndrom (white fingers)
Reducing contact stress
Change posture
Use gloves
Use design-friendly tools
Use grip surfaces that are smooth, non conductive
of cold or heat and anti-slip
Loisa Sessman, Halmstad University
16. Repetition
High repetitive work require more muscle effort
The muscles need more time to recover
Vary postures can reduce repetitive movements
Loisa Sessman, Halmstad University
17. Other causes
Temperature
Cold
• Blood circulation
• Time for recovery
Heat
• Sweat – slip
Vibration
Blood circulation
Require greater grip force
Try to isolate the vibrations!
Loisa Sessman, Halmstad University
18. Conclusion
There are several musculoskeletal disorders caused
by extreme postures, forces, high repetitive work.
Also hand-tools and environmenment
can cause injuries.
Loisa Sessman, Halmstad University