Simple answer don't do it. Although my original RSD was in my hand I could not understand why everytime my heels hit the grund a wave of pain went through my hand. The explanaion I was given is tht this scrambles the pain centre of the brain so that signals even pleasurable ones from any part of the body can be tred into pain ones and transmitted to the rsd area.
Any exercise should be gentle and you stop at the first sign of rsing pain.
The slightest trauma can cause it to spread and it does in 77% of us and certanly sounds as if it is in you