What does the word flexion mean? by Fusion Rehab | Oct 28, 2021 | Pain, Uncategorized | 0 comments Bend. You see this term come up all the time in discussions of physical therapy etc. Submit a Comment Cancel replyYour email address will not be published. Required fields are marked *Comment * Name * Email * Website Save my name, email, and website in this browser for the next time I comment.