dear sir I understand your concern.the most possible explanation would be low sugare.the research telling there is fair chance of gritting low sugars for the people who are in strict Controll.the next possible thing can be diabetic neuropathy, to rule out above conditions kindly check your blood sugars little offend for about four days.this will give clarity if you are suffering form low sugar.if low sugars are not there try taking tab neurobion which can help your nerves to stay healthy and avoid this kind of weakness,,,,,,regards