Melanie is moving some boxes from a cart into the supply room for sorting. The boxes are not large, so Melanie knows she can move them without assistance, and she gets started moving them right away. For the next hour, Melanie moves boxes from the cart in the hall into the supply room. She had a back injury in the past, and learned to bend her knees before lifting. Afterward, she opens the boxes and, feeling tired, uses her feet to push them around to the correct areas of the room before sorting and storing the supplies.

Melanie demonstrates the correct use of body mechanics when she: