I've had problems on and off for a few years, mostly related to periods of intense hiking or cycling when my haphazard stretching regime obviously doesn't keep up with the amount I'm exercising!
My problem is due to poor knee tracking and strength which results in the IT band getting aggravated as it is being asked to work in directions it is not intended to. As a result, on the climbs the IT band gets stressed and aggravated, and when the tension is removed (on the descents) it starts to hurt. The pain is located in the same area as yours, although also at the sides and behind the knee.
I have managed to alleviate this to some degree by doing all the usual runners exercises and stretches including foam rolling the top and outside of my calves and outside of my quads, stretching quads, calves, hips etc. but also by adapting my pace, I try to maintain a quicker pace but smaller steps on the uphills (almost like shifting into an easier gear on the bike but increasing your cadence). This means less stress on the knees as I'm not taking such big steps.
I also use poles on the ascents, especially on multi-day trips with a big bag.
Again, for the multi-day trips I try to pre-empt problems by taking a regular course of Ibuprofen throughout.
I'm surprised nobody has mentioned your IT band, either here or at your physio, but perhaps there is something I've missed, after all, I am not a doctor etc etc
