Kinds of Back Injuries

• Back strains-When weak or tense muscles are stretched beyond their limit

• Back sprains-A partial or complete tear of a back ligament

• Herniated discs-Resulting when stress, strain or gradual deterioration on a disc causes it to stick out between the vertebrae

• Ruptured discs-When the wall of a disc breaks open.

Much of the work in ergonomics and human factors concerning the back deals with the lower spine, specifically the area immediately around the L5/S1 (interface between the fifth lumber vertebrae and the first sacral vertebrae).

This region was chosen because of statistical data regarding back disorders. – According to Frusen, et al.,

1965, Smith, et al., 1944, Armstrong, et al., 1965, 95% of all herniated discs occur in this region.

– In addition, data suggests that the L5/S1 incurs the greatest stresses during a lift.

• Lifting of heavy objects

• Moving and lifting bulky objects

• Lifting objects from the floor

• Lifting objects frequently