EE was changing the cement valves top of Grp 2 silo. The 1st bar valve moved hard. EE used full body weight on the 2nd and it moved easier causing them to be off balance. EE rolled R ankle. EE iced it and took ibuprofen. Worked for 2 weeks then decided it was not feeling better. EE went in for an x ray on 3/1. Displaced fracture R distal fibula.