hi, thank you for providing the brief history of you. A thorough neuromuscular assessment is advised. As your chief complaint is that when you walk there is a sharp pain in the lateral side of the left foot, I suspect it to be muscular pain or either neuropathic pain for which a thorough neuromuscular assessment is advised. Also. when there is a nerve impingement in the lumbar spine, it all starts with the pain in most cases on the lateral side of the foot. As you even mentioned that you had a bony injury in the past, there might be a tendency of abnormal gait during that time and shortening of muscles of the spine due to walking in pain. As I feel, by strengthening the muscles of the core, spine, pelvic floor and lower limbs on both sides you should be able to walk. Since the nerve impingement gives the initial symptoms as pain in the lateral side of the foot and progresses over a period of time. So before it gets more on future you can get an MRI of lumbar spine and them proceed with physical therapy for the lumbar spine. In my clinical experience I see cases who initially comes with this sort of pain and later with Nerve impingement diagnosis. So, from past couple of years I have noticed that this is the first alerting symptom of the Neurological pain so now I deal with first an MRI of spine and core stability. Results come on 3-4 weeks of time and post which in future complaints are less Regards Jay Indravadan Patel