If humans didn't have bones, they would not be able to move their arms, legs, head or neck. Humans would be a soft blob of tissue, muscles, skin and organs. Many important organs would not be protected, such as the brain, spinal cord, lungs and heart.
Bones provide more than the ability to move, as they are vital for metabolic functions as well. Bones store most of the minerals that the human body needs to function. Bone marrow stores essential fatty acids that the body uses for energy, as well as heavy metals and toxins, keeping them away from organs until they can be released from the body as waste.