Aside from its large size, Megatherium’s skeleton is extremely robust in its construction, and seems to be built not just to support its large body but to provide the maximum amount of stability. The lower bones of the short hind legs are comparable to the femur in thickness and development. Combined with a short but thick tail and a broad pelvis, the lower body effective becomes a seat for which the upper body can rest on. The price of this lower body development is that Megatherium certainly would not have broken any records for speed, and may have been one of the slowest animals in its ecosystem. However this would not be a problem as Megatherium probably would not have had to run to or from anything.
