Spinal loads during position changes

BackgroundRecommendations exist how patients should change from one body position to another in order to keep the spinal loads low. However, until now it is not clear whether the loads are in fact lower if the patients follow these recommendations. The aim was to measure the loads while changing the body position.MethodsTelemeterized vertebral body replacements have been inserted into 5 patients who had a severe compression fracture of a lumbar vertebral body. The acting loads were measured during a changing of the body position while lying and when moving from lying to sitting, from sitting to standing and vice versa.FindingsWhen the lying patients changed their position according to the physiotherapist's recommendations, the resultant force was nearly as high as it was during relaxed standing. Otherwise, the force was nearly twice as high. Changing from a lateral lying position to sitting and vice versa caused forces of about 180% of those seen for standing when the recommendations were heeded. Without instructions, the loads were about 70% higher. Use of a trapeze bar mounted to the bed did not increase the loads. Rising from a chair with the arms hanging down laterally led to average resultant forces of 380% related to standing. Placing the hands on armrests reduced this value to 180%.InterpretationHigh forces may act on the spine when changing from one body position to another. These loads can be minimized when following the physiotherapist's instructions and when supporting the upper body by the arms.