Low back injury risk during repositioning of patients in bed: the influence of handling technique, patient weight and disability.

The objective of the study was to investigate the low back load during repositioning of patients in bed and to assess the influence of patient's weight and disability. Nine female health care workers (HCWs) carried out six patient-handling tasks with different patient weight (59 +/- 1, 83 +/- 2 and 110 +/- 4 kg) and handicap (hemiplegia, paraplegia and near-paralysis). The tasks were performed with optional use of simple, low-tech assistant devices (draw and sliding sheets). Peak low back compression exceeded the National Institute for Occupational Safety and Health action level of 3400 N in 25% of all trials (418). The influence of the HCW, i.e. the technique and assistive devices used, was higher than the effect of weight and disability in all tasks studied. ANOVA showed that on average for the six tasks 37%, 10% and 6% of the variance in low back loading was caused by variation in the factors HCW, patient's weight and disability, respectively. The result of this study is relevant for HCWs. It is shown that the repositioning technique and use of friction-reducing devices have higher influence on the low back load of the HCW than the patient's weight and disability.