Hi, Thanks for writing. As per your description, it seems that you might have sustained a wedge compression of your lumbar vertebra which will show up as a swelling externally owing to the prominence of the spinous processes. Also during the same accident,your intervertebral disc
annulus might have been torn causing pressure over the exiting nerve root
. Whenever you bend forwards this disc impinges over the nerve that gives a shock
like sensation down your leg. If you are much worried about the problem, get MRI
scan of your Lumbosacral spine that picks up all the issues. Follow an Orthopedic surgeons advise accordingly. Wish you a quick recovery.