Re: Pain in groins and thighs!
Whenever someone complains of being unable to stand or walk for long, I immediately think of stenosis. This is a narrowing and it can occur in the central canal or in the foramen, which are openings located at the vertebrae which allow the spinal nerves to leave the spine and travel out to the limbs and other parts of the body.
When one of these areas becomes narrowed or clogged, the nerve can become compressed. This results in pain that can be felt in the back or anywhere along the path of the nerve. For example, if the L4, L5 or S1 nerve ends up getting squished, one can feel the pain in the groin, buttocks, leg and even foot and toes. This is the type of pain people often call sciatica or sciatic pain.
There are a number of issues that can contribute to stenosis. A bulging disc that extends out from the disc space can cause stenosis in the adjoining foramen, or can push back into the thecal sac that surrounds the central canal. Arthritis can cause the facet joints (the synovial joints located at each vertebral body) to enlarge, which causes narrowing of the adjoining foraminal openings. Arthritis causes bone spurs to form which also contribute to stenosis, etc.
Prior to 2008 I had severe stenosis and eventually could not stand for more than a minute or two -- I couldn't stand long enough to chop an onion without severe pain setting in. I then had surgery to open up these areas...and more surgery in 2010 and can now walk as far and long as I want.
You can find lots of information online, including excellent photos and diagrams that will help you to understand what is most likely causing your pain. I imagine if you have a MRI you will be able to see it for yourself.
Good luck. Opening these channels might resolve at least most of your pain.