OBJECTIVES: The effects of height-adjustable beds in hospitals on the subsequent prevalence of low-back problems among nurses depend on the capacity to reduce low-back stress by bed-height adjustment. This capacity was investigated in the present study. METHODS: Professional nurses performed patient-handling tasks at a standard and an individually chosen bed height. Peak values and time integrals of spinal compression and shear forces were estimated with dynamic biomechanical modeling. RESULTS: The bed-height adjustment led to lower values of time-integrated compression (average 8.8% lower), peak shear force (average 9.3% lower), and time-integrated shear force (average 18.1% lower). No significance was found for the effect on peak compression, nor for the results for each individual task. This finding can be explained by the minor adjustments made in comparison with the standard height or by the application of different criteria for bed-height adjustment. CONCLUSIONS: The decreasing time-integrated forces and peak shear force, without a concomitant rise of peak compression, speak in favor of the use of height-adjustable beds in nursing.
OBJECTIVES: The effects of height-adjustable beds in hospitals on the subsequent prevalence of low-back problems among nurses depend on the capacity to reduce low-back stress by bed-height adjustment. This capacity was investigated in the present study. METHODS: Professional nurses performed patient-handling tasks at a standard and an individually chosen bed height. Peak values and time integrals of spinal compression and shear forces were estimated with dynamic biomechanical modeling. RESULTS: The bed-height adjustment led to lower values of time-integrated compression (average 8.8% lower), peak shear force (average 9.3% lower), and time-integrated shear force (average 18.1% lower). No significance was found for the effect on peak compression, nor for the results for each individual task. This finding can be explained by the minor adjustments made in comparison with the standard height or by the application of different criteria for bed-height adjustment. CONCLUSIONS: The decreasing time-integrated forces and peak shear force, without a concomitant rise of peak compression, speak in favor of the use of height-adjustable beds in nursing.