Protection plates on ladders are used to prevent damage at which points?

Protection plates on ladders are specifically designed to prevent damage at chafing points. These are areas where the ladder may come into contact with rough surfaces, other equipment, or even itself during operations. Chafing can lead to wear and tear, compromising the integrity and safety of the ladder over time. By using protection plates, the ladder's structural components are shielded from abrasion and damage, thereby extending its usable lifespan and maintaining safety standards.

Other choices reference different aspects of ladder construction and maintenance; joint connection points pertain to where ladder sections meet, while rungs refer to the steps on a ladder and extension points relate to the mechanism that allows the ladder to expand. However, protection plates are primarily focused on chafing points to address wear from contact hazards, making this the most appropriate choice.