Hi Sarah
First off I am not an expert sports physio. So someone who is may recognise the description as a the presentation from their experience. However to me, the description to date gives me no real clues to what is going on so I am no further forward. So because I am can't use pattern recognition I have to apply clinical reasoning through to the problem just like you and in that way I am no further ahead than you in solving scousewil's riddle.
This is where the futility of a text-based internet discussion is so futile. From what he has said I don't know:
1. the accuracy of his description
2. whether the points he has made are important to solving the problem
3. what actually does matter. The patient has tried to diagnose himself and wants confirmation of his diagnosis. He could be right - but in reality this may just be a red herring. There are HUGE amounts of information missing so I would want to start a fresh.
Pain/symptoms - we know something about the location of the symptoms(althugh the foot is very intricate and a slight error could put us way off the trail) but nothing about the type of pain (could be useful to identifying the tissue type and the pathology) the behaviour of the pain - other than running under two different conditions we don't have a clear description of what makes it worse, the irritatbility and latency of the pain. The pain appears to be variable and therefore heave a mechanical component but is it always there just gets better when he doesn't run? or is intermittant? And what about the 24 hour picture.
We have no objective information. Personally as I have a strong biomechanical base so I would put a lot of weight on observing his running and walking on a treadmill. In my experience a few seconds into watching what he does may give the clue away. I would also look closely at the the posture and muscle function to see what movement impairments if any I can identify - and if he has really had a shortened plantarflexor group then this would show up positive. Then there are the more usual and mundane tests: AROM PROM clinical tests.
I think you can see the point I am making - it is all about a good assessment. Half the time when patients give descriptions on this website you really are no further forward in knowing what is going on (sorry scousewil if you get to read this - no offence meant - just the nature of media really)
so I know I haven't answered any of your direct questions. However can you see why that may just be more red herrings? Before generating anymore hypotheses about what is going on you need to go back to the observing the facts and building up the clinical picture.
Question for you: do you believe at this stage in your development as a physio that you understand WHY you ask each question in the history (eg what does irritability of pain really mean?) and what each test and observation in the objective actually means?
I ask that because that is a real key in improving your diagnositic skills. We often start by rote learning the set points in an examination but until we really know what it means we tend to make a lot of mistakes along the way that we can't correct.