Trunk motion characteristics during different patient handling tasks

Abstract The objective of this study was to investigate the kinematics of the thoracolumbar spine during commonly used patient handling tasks. Special emphasis was on the identification of exposure variables describing asymmetric working postures. Ten female health care workers (HCWs) performed nine patient handling tasks including turning, lifting and repositioning a male stroke patient. Kinematic data were obtained with a Lumbar Motion Monitor ® and muscle activity was recorded with surface electrodes from the erector spinae muscles. Patient handling requires extensive angular displacement in the sagittal plane in excess of what is normally seen in industrial manual material handling operations. The majority of the kinematic data, however, demonstrated a pronounced lack of task specificity. The variance between HCWs was high when performing the same task, and position, velocity and acceleration parameters showed a greater variance between subjects than between tasks. Only few differences between single tasks were found in the frontal plane of motion, and three patient handling tasks showed higher exposure to asymmetric back postures. The general implication for patient handling tasks is that a description of task exposure and task distribution is difficult to use in a risk assessment based on kinematic data due to the large individual variance. Relevance to industry Job exposure is generally seen as a weighted sum of the different task-specific exposures constituting a job. The lack of task specificity for kinematic data obtained during patient handling emphasizes that care must be taken when this approach is applied in job exposure surveillance in e.g. the nursing home industry.