I had a car accident around 6 months ago and suffered whiplash which effect my neck and back. I underwent treatment with physiotherapy, however, after recently lifting a heavy object at work I am currently suffering very severe pain in my back, ranging from mid to lower back. I am also experiencing sharp stabbing pains starting from my left knee and radiating up my leg, my knee wasn't a problem till now. As well as a 'popping' sensation behind knee and in left ribs. Any help?