I Have RRMS And Balance Problems Which Are Not So

I have RRMS and balance problems which are not so severe at the moment. However I find that after a short period of walking (say 1km distance), my legs become extremely painful with the pain concentrated in the knees, foot and ankle. Last night, I dropped a sandwich press on my foot and it is currently being investigated for a fracture in the metacarpal (2nd and 3rd) and have been advised to use a crutch or something until the radiologist report becomes available to confirm if there is a fracture. However, I am starting to feel like that if I walk any distance, that a cane may help me keep going and lessen the pain. So, when is the right time I should be thinking about a cane? I know it is a common question, I do have difficulty getting up and down out of chairs and the car. Other then the MS (main problems with that is balance and cognitive), my health is good.