- a residual of an old injury to the tendon, especially if you have given your foot a period of rest and now you are back to using it, 

- a chronic injury of the tendon, producing subtle, insidious onset of pain posterior to lateral malleolus that progressively worsens in terms of both function and the level of pain,

- Tendon impingement, a chronic type of injury, typically occurs far out from an acute injury.Usually, you would feel better for weeks after an ankle sprain, only to have the pain get worse with activity without any provocation. Pain is precipitated by loading the foot, but it tends to be inconsistent during the day and week. Pain may be more prominent after being immobile or waking up in the morning, but it improves over time. 

To pinpoint the exact cause of your ankle pain, a proper examination of the affected foot by a physician is recommended.