What Causes Knee Numbness And Tingling In Left Hand Caused After A Back Injury?

About four hours ago I slipped and fell on ice - landing on my back. Initially my entire body was numb.mafter a very few minutes I could roll onto my knees and stand up, but both area were numb. After 30 min feeling returned to my right arm. My left hand is still tingling - I have feeling, but it is 'asleep'.