Straight leg/stoop position
THIS IS WHAT NOT TO DO!
- High compression forces on the lumbar discs
– Compare 500N force in stooping compared to 340N for squatting! - All the load is on the spine, which has only small muscles
- Increased force in the spine when the load is held away from the body
- During flexion/stooping the back muscles are less active, which puts extreme strain on the lumbar ligaments
- This should NOT be done whether you are picking up a pen or a box
The leg lift or deep squat
- The most commonly taught method of low lifting
- The knees and hips need to be almost at maximum bent position, with buttocks close to the ground
- There is less stress on the lumbar spine, ligaments and muscles
However there are limitations:
- Significant stress on the knee joint
- Poor stability through the lift action
- The strength and endurance required to extend the knees and hips under load is great
- Lift is not very adaptable
- There is reduced mechanical effectiveness of the ankle, knee and hip joints
The Semi-squat
The Semi-squat is now widely accepted as a preferred approach to lifting items from low levels as it provides the best stability, power, endurance, vision and adaptability.
Patterns of movement:
- Spine is in or close to its normal shape
- Knees are moderately bent within mid range
- Trunk is inclined forward to grasp load
- Feet are apart
- Shoulders are aligned
- Load is held symmetrically
- Load is held close to the body
- Hips and knees work smoothly together to lift and lower the load
