Another one with a knee issue, in some ways sounds similar to what Adrian has described above.
Symptoms: Knee click, tightness on inner part of hamstring during squat with weight, general left ankle tightness. The knee feels odd after squats/cleans/deads/anything that involves load.
What I’m doing about it: Stretching, foam roller, ITB/glute release with tennis ball or similar
History: Since Nov 2008 have had this issue (around that time I did a Movember fundraising run, 3x400m in the 40kg vest)
Have seen Physio, Osteo, Sports Doctor, in that order. Original diagnosis was a strength imbalance between the outer quad and the inner quad (sorry, the correct terms elude me) leading to the patella tracking incorrectly, and the click. I tried the exercises prescribed to strengthen the inner quad, but never really believed this to be the case and lost interest. I was also not seeing results from the exercises.
Osteo prescribed plenty of stretching (to be done every day) and after no major improvement, wanted to send me to a specialist for a scan, which sounded expensive. I didn’t really have faith in the opinion and didn’t have the scan done.
Sport Doctor diagnosed it as “Patellofemoral Joint Dysfunction” and that the cause was weak, tight glutes combined with poor footwear (Nike Frees) and the >50% increase in mass during the run. The prescription was to go back to the Physio for glute release and strengthening of glutes & quads.