This problem is caused by tightness or tethering of the obturator nerve as it leaves the pelvis and enters the thigh. It may be caused by scarring from an earlier injury, or muscle tightness. It is a rare condition, and quite hard to diagnose.
The most common sensation in pain felt down the inside of the thigh with activity, which may be associated with numbness on the inside of the thigh.
If you think you have this injury it is well worth getting it checked out by Mr Willis-Owen. In the mean time you should avoid any aggravating activities with may prolong the problem. It generally won't get better on its own. The first thing to do is reduce your activity and start gentle adductor stretching.
Treatment involves first confirming the diagnosis then establishing the underlying causes. This may involve nerve conduction studies. Options may include activity modification, physiotherapy, stretching and anti-inflammatories. Vary rarely surgery is required.