Pain did not end after knee surgery so I asked for PT. My PT said my knee problem was caused by weak muscles that do not keep my joints in good alignment. However, I cannot be trusted to do boring, time-consuming exercises that never end because my weakness will never fully go away. Steinberg (1) says adding another chore "stands little chance of lasting over time." When I was an OT I did not know how mind-numbing exercise is when it must be done every day until a client with a chronic condition dies.
I find it easier to incorporate an exercise into a habit than to add another exercise to my to-do list. In the 13 years since my stroke I learned I will do 3 to 5 repetitions every day IF I use a familiar object as a memory aid. I call doing a few reps every day forever a mini-exercise. Here is one of the mini-exercises I added to my daily routine because I do not want knee replacement surgery.
My PT had me do lunges to strengthen my knee. My knee wobbled left or right (red arrow) as it bent because my hip muscles are weak. After 1 or 2 reps my knee stays lined up with my foot (green arrow) because hip muscles start to work together to keep my knee in the midline. I chose the toilet to prompt me to do a few lunges. On his TV show Dr. Oz showed how much water sprays out of a toilet when it is flushed so I got in the habit of lowering the lid before I flush. I have to wait for 10 seconds so I may as well do lunges.