Many people, even those well educated in medical sciences, DO NOT practice proper lifting with any serious consideration to the exquisite requirement of the dynamics of the vertebral column.

The vertebral column Only transmits forces along its back half.  That is the portion of the vertebral column that does the lifting is located behind the spinal tunnel.  This hosts the most vital structure of the body: the spinal cord.  

The front half of the vertebral column Only deals with cushioning the forces of vibration by virtue of its vertebral discs.  These discs act like the struts of an automobile.

Thus there is one way of lifting that is safe: Maintain very straight, or better, concave (arched backward) lower back when lifting anything.  Even lifting your own body while leaning on a sink could precipitate serious injury to the spinal cord.  That is not all to it?