LOADS%20and%20LIFTING

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LOADS and LIFTING
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• Back pain is big
• Back troubles
• Are painful
• Reduce activity and mobility
• Cause absences from work
• Affect a relatively young part of the work force
  (age 20-40)

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Whos most affected

• Physically active jobs
• But cant usually be pinned on a single incident

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Understanding Back Pain

• Why is most back pain in the lower back?
• What are early physiological changes in the back?
• What are the eventual results of continued
  deterioration?

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How is Back Pain measured

• Intervertebral disc pressure
• Biomechanic modeling
• Intra-abdominal pressure
• Subjectively

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Intervertebral Disc Pressure

• Idea is that bending back puts uneven pressure on
  the discs
• Lift with your back straight
• Force transferred through arms and upper back
  creates torque

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Biomechanical Models

• Torque Fd
• Bent back increase torque through distance
• 20kg load has a predicted compression force of
  12, 138N (huge)
• Farther load is from the spine, the greater the
  torque

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Intra-abdominal Pressure

• Pressure created by abdominal muscle contraction
• Hernias
• Lifting belts
• Suggest 90mmHg is a safe limit
• Weightlifters can go much higher 150mmHg

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Subjective Approaches

• Obtained by questioning is this too hard? Too
  easy
• Look at Tables 7.2-7.4 in text
• Acceptability by Lift Weight and Lift Height
• For Different Actions lifting lowering pushing
  pulling

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Problems with making Lifting Recommendations

• Vary with individual health and fitness
• Vary with type of load
• Vary with lifting technique
• NIOSH limit 23kg max
• All lifting situations need to be examined for
  safety

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How to Lift Properly

• Keep your back straight, bend your knees
• Keep the load close to your body
• Try to have the load start at knee height, not
  from the ground
• Provide handles or hooks
• Dont rotate or twist
• Use mechanical aids if possible
• Pushing and pulling is easier than lifting if the
  force can be transferred.