What does the bent body of the man with the hoe signify?

In Markham's "The Man with the Hoe," the man is bent over because of "the weight of the centuries" (line 1) that he bears and because of the weight of the "the burden of the world" (line 4), which presses down upon him. This is a homage and a lament for the working man throughout time, who toiled in the fields or a steel mill, oppressed by the wealthy few, who have through their greed oppressed working people, taken away the light and music in their souls, condemning them to long, grueling days and nights of work, for virtually nothing in return. This poem is based upon a painting of the same name by Jean-Francois Millet. The painting portrays a man who is bent over, working a rocky ground. The plight of the working man has not really changed much throughout history. In spite of modern features such as minimum wage and OSHA regulations, many working people are still bent over metaphorically, if not literally.