Sciatica - do I need to change my job / desk / lifestyle?

[NotOnTheBench]

Since starting a ft job as a database admin, c3 years ago, I seem to be developing various health issues that I put down to sitting for far too long. Knee issues which I think are more due to running, but if I sit too long my right knee will seize up + become excruciatingly painful (I have had to leave theatres due to almost passing out with the pain if I'm in a seat where I can't stretch out).

Now I've been running with sciatica since January, which has been mild until I 'put my back out' a couple of days ago. Its not that bad now, but still getting spasms down right leg. Want to try a run round the block at some point today. I've been a runner/jogger for over 35 years so am a bit cross right now.

Any advice? Apart from getting up every hour to do physio which I admit I don't do regularly.

See your GP. Possibly early signs of osteoarthritis. Also see Osteopath re back pain, sciatica and knee pain. They are likely all linked.
Move around at least every half hour at work. Consider less high impact exercise than running, eg swimming, walking, cycling. Choose seats at theatre/cinema that have leg room or are on the end of an aisle so you can get up and move around a little. I’m a regular cinema goer and I always get a seat on row where there’s room to do lower leg raises and calve stretches otherwise I can’t move for a while after the film. Think of the synovial fluid around the knee joint as cement. You’ve got keep the joint moving a bit to keep the fluid flowing. If it’s static for too long it will start to stiffen up and that’s where the pain and immobility comes in.