What is a basic principle of proper body mechanics?

Using leg muscles by bending at the knees is a fundamental principle of proper body mechanics because it helps to distribute the weight of the object being lifted more effectively. This method engages the strong muscles of the legs, significantly reducing the strain on the back. When lifting heavy objects, maintaining a straight back while bending at the knees allows the lifter to keep the load close to their body, thus minimizing the risk of injury. This technique is essential in preventing musculoskeletal injuries, which are common in nursing and caregiving professions where lifting and moving patients is frequent. Emphasizing the use of leg strength rather than the back or arms ensures the safest and most efficient lifting posture.