Going back to the original movement
There are many differences between executing lifting or transporting movements of objects that possess an easy grip (such as a cat bell) and objects of a more natural shape such as stones or trunks; it depends on the intent of the practice. Mainly, the use of more natural-shaped objects prepares us for daily activities. In everyday life, what we need to lift or carry has hardly a specific handle that allows us to balance the weight in a perfect way.
Moreover, every stone, trunk or simply every object of daily life require a different grip and a different partition of the load, perhaps also carried out on an uneven ground; As a clock work, the body must rearrange the movement in a new way. All this is transformed every time into a new stimulus for muscles, tendons, ligaments, bone structure and nervous system, to which the body responds with a different adaptation, that in itself is a way of growing and evolving that leads to develop practicality and adaptability in movement.