It could be a really bad sprained muscle in basically the butt area were the big muscles in the rear connect to the top muscles to the back leg these are really deep big muscles.The reason I know is I have pulled these same which also causes a pinched nerve I have pulled these muscles in the past and have had the same symptons.Im thinking the same pain from hip to knee is sciatica which is a pinched nerve which also causes a a burning and numbing feeling in the front of the leg plus pain.As a matter of fact I just did the same injury in Texas when someone spilled some water on the floor and my right leg shot out from under me that hurt so bad.It was a miserable drive from Texas as the driving position in my truck just made it hurt more cruise control did not help cause its the position you are sitting in.The only relief I got was to stop the truck and get out and stand that stopped it right away.
Then I could drive maybe another 50 miles before having to stop again.
Nothing a good chiroprator cant fix.
Let me know if this sounds familiar if so no surgery needed.
But I must say it takes a long time to heal
I say chiropracter is because when you jerk your body that hard you also become out of alignment you will know if you seem to think one leg is shorter then the the other when you walk and you also feel like your back is a bit twisted.