Deep Scar (3.5e Flaw)
From D&D Wiki
You have suffered a deep wound somewhere on your body that prohibits you from partaking in greatly strenuous activities.
Effect: Whenever the character fails a strength check by 4 or more, they aggravate the old wound and is shaken for 1d4 rounds. Furthermore, they take a -2 penalty to all fortitude and reflex saves.
Roleplaying Ideas: How did the character acquire this grievous wound? Are they searching for a way to fix their now hampered physical form or are they merely try to cope with it? They may have even lost the will to fight unless absolutely necessary for fear of aggravating the wound.