The human body was designed in such a way as to be able to do many things. As an Otho Tech, I help many patients, whose bodies are not working properly, move from one place to another. If I didn't use proper body mechanics, I would probably hurt myself and the patient. Using Body Mechanics means we work with the design of our body to accomplish action efficiently and effectively.
Paul is trying to get the Corinthians to understand how the body of Christ is to function. He draws on the metaphor of the human body, which is so appropriate. Paul is going to make a couple of powerful points that may change the way we think about the body and about our relationship to the body.
Also we need to remember that this is in the context of explain the proper use of spiritual gifts.