What are the three cranks on a manual bed and what does each one do?

The three cranks on a manual bed are each located at the foot of the bed. The left crank raises or lowers the head of the bed. The right crank adjusts the knee portion. The center crank raises or lowers the entire bed horizontally.

Manual beds have cranks at the foot of the bed. The left crank controls the head of the bed, allowing it to be raised or lowered. The right crank adjusts the knee portion. The center crank raises or lowers the whole bed as a flat surface. Cranks are pulled up for use and kept down at all other times for safety.