Fig. 2From: Complex biomechanical properties of non-augmented and augmented pedicle screws in human vertebrae with reduced bone densityRepresentative screw displacement of a non-augmented vertebra under preload (condition 1) and cyclical load (condition 2) over 13,000 cycles until the machine limits are reached. Top: The screw head moved in cranial direction (positive sign). Bottom: The screw tip moved in caudal direction (negative sign); preloaded; loaded = preload + cyclic loadBack to article page