The document discusses body mechanics, which involves coordinated muscle and skeletal movement to maintain balance, posture, and proper alignment during patient handling tasks. It defines the four components of body mechanics as posture, base of support/center of gravity, muscle groups, and lifting technique. The document outlines several principles of proper body mechanics, including maintaining a wide base of support, keeping the line of gravity vertical, and proper body alignment. It also discusses the importance of body mechanics for preventing injuries when assisting patients.