From BestLife:
Defenders of stationary equipment argue that machines are designed to limit what you can do wrong. But seated machines often put heavier loads on the back and joints than is necessary, and almost always miss the mark when it comes to replicating the movements found in everyday life, according to Ultimate Back Performance and Fitness, by Stuart McGill, PhD, a professor of spine biomechanics at the University of Waterloo, in Ontario. For this list of exercises, we consulted McGill; Nicholas DiNubile, MD, author of FrameWork: Your 7-Step Program for Healthy Muscles, Bones, and Joints; and trainer Vern Gambetta, author of Athletic Development: The Art & Science of Functional Sports Conditioning.