Ancient Astronaut Theory

[Rayaan]

There is also evidence that the builders of the pyramids used to do heavy labor because autopsy studies of their bodies have shown that there are signs of stress on their spine and backbones (and also in the knee and leg joints). This means that the workers had to physically push and/or pull the weights with their own bodies even though they may have used other equipments as well.

Degenerative arthritis occurred in the vertebral column, particularly in the lumbar region, and in the knees. It was frequent and more severe than in the skeletons from the mastaba cemetery. Skeletons of both men and women, particularly those from the lower burials, show such signs of heavy labor.

This is also interesting:

The pyramid builders were not slaves but peasants conscripted on a rotating part-time basis, working under the supervision of skilled artisans and craftsmen who not only built the pyramid complexes for the kings and nobility, but also designed and constructed their own, more modest tombs.

Source: http://www.guardians.net/hawass/buildtomb.htm