English: This video is a supplement to a NIOSH publication 2011-191, which consists of a series of demonstrations designed to complement training on ergonomic principles. Each demonstration highlights worker participation and uses relatively inexpensive materials. The demonstrations are organized by type of ergonomic principle. Five general topics are addressed: 1. Neutral compared with non-neutral postures; 2. Grip types; 3. Hand-tool selection and use; 4. Fatigue failure and back pain; and, 5. Moment arms and lifting.