My sister is 49 year old. Her weight is 80 kg and height 5'1. She's suffering from extreme muscle weakness. From last month or so she's feeling extreme pain in legs while walking. Lately, it's been almost impossible to walk because of pain. We have tried every other pain relieving sprays or balms, but to no avail. Also, because of muscle weakness, she couldn't do exercise also. Can you suggest any swift and relaxing remedy/spray for the same?