Ok your in luck as i'm good to answer this type of question. First off your gonna hate to hear it but rest. You have to otherwise you'll just aggrevate it until you need an operation. By rest i mean two weeks to a month minimum. I'll repeapt that so it sinks in and you don't dismiss it, no squats, no lunges, no hanging leg raises, nada for two-weeks to a month. Not even runs or walks on a treadmill. Let it repair. Ice it, use ibruprofen, get rid of excess fluids. If your overdoing it the tissue will grow back matted rather than in an elongated fashion, don't stop eating clean, just give your body a chance to repair. Swimming is prob fine, no breast stroke. If it's been gradual and progrssive it means you haven't let it rest.
Right assuming you have been good and rested, buy your self some lycra or neoprene shorts. Long enough to reach the knee at least. Wear them under training bottoms I want you to get heat to the area. Start with a mixture of cardio, start with the concept 2 rower if you can for 5-10 mins, then walking on a treadmill, building the speed to about 7-8km/hr. On average that is a pretty uncomfortable speed to be walking at. Do not try to jog or increase the speed to walk without correct posture. It should feel uncomfortable, particularly in the shins it's meant to. Start with intervals until your able to maintain posture without major discomfort at that speed. Do this for 10-15 mins. You should be pretty hot by now, if there is aslideboard available do a good 5-10 mins on that too. Now go straight onto some bodyweight lunges. They must be bodyweight, don't even consider adding weighs. First set keep it short, emphasis on the quads, then gradually lengthen it takeing it to the glutes and the furter so it's pretty much hitting the hamstrings, hip flexors and adductors. These movements should be very slowly lowered and without bouncing. The front foot should always remain in front of the leading knee. In between sets add some good mornings without weight and lay on your back and slowly with a controlled fashion open and close your legs. Open as wide as possible do not drop the legs forward, they should return together with your body bent at a 90 degree angle. Finish off with some bodyweight side lunges, keep the bent leg's foot in front of its knee, slowly deepen the stretch by pushing the knee outward with your elbow. After this do some decent and controlled stretches about the groin area. DO NOT BOUNCE.
What are you doing here? your warming up thouroughly, the lycra prevents the heat from escaping and keeps the internal temp above the critical 32 degrees required. The moves contain a lot of controlld eccentric movements about the groin area, and should result in controlled micro tears about the scar tissue. With sufficient quality rest and nutrition in between the scar tissue can be safely broken down and quality new tissue can replace it, Adding ice and massage won't harm the process. Stay off the roids, as roids and flexibilty don't particularly go hand in hand as you'll be repairing and adding new tissue faster than breaking down the old scar tissue. It will just get messy, and by the sounds of it your in a pickle anyway.
I now i'm gonna repeat myself but i could almost bet you won't refrain from aggrevating it further instead of resting. REST, REST, REST first. Does this work? Yes, How do I know? Did the exact same thing myself after spending time away from tumbling and wondered if I could still do box splits. You wanna see the size of the bruise I had, from my groin to about 2 inches off my knee. Very silly, spent about three months correcting it. Well 4 weeks rest 2 months to get past the pain and get box splits back.
Either way good luck! A.
One other thing, from the bruising and the obvious immediate pain, at a guess i'd say my injury was a more surface injury, although it looked horrendous..either way if yours runs deeper take care when lowering yourself into anything like the above as you prob won't have the visual reference that i had when overdoing it.
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