I pulled the groin muscle on my rightleg by sitting on my exercise bike too long in a bad position and sleeping on a bed that exacerbated my pain. It was really bad for quite a few days and even though I tried pain killer and a groin/upper thigh wrap (aff) from Amazon, and even tough it was a great wrap and alleviated my pain when walking around, driving was a bear. It got even worse when I was sitting down and getting up turned out to be excruciating.
After getting up from bed and tossing and turning for most of the night, I seem to have come up with a simple stretch/exercise that immediately reduces the pain and if practiced regularly, seems to keep the pain at bay.
Please know that any offer of therapy or treatment offered on this page or blog does not come with a warranty or a promise of any kind. I am not liable for your body if you make your pain worse. Please proceed with caution and at your own risk. You should contact your physician if there is continued pain or the pain is chronic.
A lot of groin muscle pain exercises are explained on this page in detail.
My steps are simple. Stand straight with your hands by your side. Put your ankles next to each other with your toes pointed outwards and your feet in the shape of a V. Then push your knees together with the muscles in your leg while clenching your butt cheeks. This should start hurting but it should be bearable. While doing this, flex/shift the side that the groin muscle pain is on and stretch the knee as much as you can, holding for up to 30 seconds. Do the same on the other side to prevent cramps. Once you have done this, you should feel immediate relief. If you do, then repeat the same exercise while sitting on a chair. That should be harder, but more effective. I recommend repeating this throughout the day as your pain comes and subsides. Do this in your car before starting on your journey and driving will be easier.
Let me know in the comments if this helped or if you have other suggestions.