I am 78 and normally very fit. Some five years ago I slipped my third disc which was in a position of not letting me sit or stand so I could only get relief lying in bed until three epidurals had finished their cause. That episode caused me to gain 40LB. From then on I have regained strength in leaps and bounds and recently have been walking a mile each morning to lose the weight i gained. However now my right leg keeps giving way and is painful when this happens in the groin area and, I cannot at times, put any weight on that leg. What is the problem. Thank you