712_12 CH 13 Manual Handling - Manual Materials Handling...

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Chapter 13
Manual Material Handling
Copyright (c) 2012 P. Neumann, BSc, MSc, LicEng, PhD, LEL, Eur.Erg
– This teaching material is not for resale or commercial use. Note that
attribution errors and missing acknowledgements may exist in this
material; for which the author apologises
Manual Materials Handling
MMH
• 27% of industrial injuries
• 60% of costs in industry
• 93 x 10 6 days lost/year
• Both acute and chronic
Peak and Cumulative loading
Konz & Johnson 2004
One time event Ongoing / prolonged
Risk
• Can be managed by better job design
1. Biomechanical Risk
– Calculate the load
2. Physiological Risk
– Compare to capability
3. Psychological Risk
Konz & Johnson 2004
Issues
What types of factors will influence risk in
MMH tasks?
1.
2.
3.
Konz & Johnson 2004
Issues
1. Task
– Adjust permanently
• Location (esp reach distance & height)
• Mass
• Grip-ability & stability
• Frequency
2. Technique - Can train but we all ‘slip up’
3. Individual - Selection or human rights
violation
Konz & Johnson 2004

2
Pushing and Pulling
• Force limits; factors:
– Handles
– 1-2 hands
– Body Posture and Grip Location
Direction push/pull etc – Direction – push/pull etc.
Konz & Johnson 2004
Pushing and Pulling
• Two hands better than one
• Force decreases with repetition
• Initial strength increases then sustained
• Pushing stronger than pulling
• Push at waist level pull at thigh level