Sounds to me like you have a problem with the spinal nerves, probably in the L5-S1 area. I would highly recommend you consult your doctor and get an MRI of your lumbar spine. If you have any nerve involvement, and those nerves are being damaged, rarely do they regenerate and can cause permnant damage.
It sounds like maybe a nerve might be getting pinched from something in your back. This happened to me. The pain went through my hip down my leg, on the outside of my leg sclose to the ankle and even into the foot. When the pressure was relieved, the pain went away. The first time, steroids helped, the next time, a lumbar epidural, and the last time required surgery to remove bone fragments from a ruptured disc. Whatever the cause, it needs to be evaluated to ensure permanent damage is not done.
Karen
The pain that runs from your buttocks down the back of your thighs sounds like sciatica. There are a multitude of reasons for sciatica, which is pain radiating from the sciatic nerve. It could be pinched or inflammed. I agree with TMA the source of this pain needs to be determined.
I would refrain form activities that produced this pain until you are property evaluated by a medical provider. Pain is an indication from your body that something is not right. And though exercise is a good thing it can be damaging when you are experience this type of pain.
Sitting in the style you describe will stretch the muscles, ligaments, etc surrounding or connecting to your hip joint. It will also flex your hip joints. It may or may not be related to your sciatic pain. As said above it could be a bursitis. Again both should be evaluated.
In the mean time you may want to use ice to the areas and whatever else helps ease the discomfort.
Take Care, Tuck
They may be related or unrelated.
Usually pain in the buttocks have a root cause in the pelvis or the knees ankles and feet and sometimes the back. Does the buttock pain go throught the entire area or is it just down by your thighs?
Hip pain rarely gives pain in the glutes.
Could you have injured the area pulled some muscles or hamstring? I'm sure you know whether you did or not.
I guess a few suggestions to the problem could be bursitis or tendinitis.
But diagnosing this kind of pain can be really tough so its improtant that you go see a dr in order to have them check it out and try to get on top of the problem so things sont get worse.
I might hold off on doing too many different exersizes until your able to just have the areas looked at.
TMA