HelloIam disabled due to a fall 13 yrs ago. It as suggested that I get both knees replaced. Very afraid to but I am bone on bone. I have sustained taking allege and glucosamine HCL and Chondroitin 1500mg and 1200mg respectively. The allege 500 to 1000mg 3x a week. I want to do something to strengthen my legs and tone my thighs. What would you suggest besides talking to my ortho?