The pain might be a symptom of mild gout. Gout is when tiny crystals of uric acid precipitate out in the poorly-circulated, so poorly flushed, synovial fluid.

The pain might be a symptom of mild gout. Gout is when tiny crystals of uric acid precipitate out in the poorly-circulated, so poorly flushed, synovial fluid. What happens if you drink an extra litre of water(or other fluid) when the pain occurs?