Old knees and trailer steps

I have the Chopat one that I bought 18 years ago when I was still running regularly. I was diagnosed with osteoarthritis at age 52 I ran until age 55. When I bought the MH 3 years later I could only sit with my knee bent for 30 mins without pain then I had to extend my knee to the top of the dog house to relieve the pain. I raised my seat to help straighten out my leg which helps. I think the strap helps when the pain is from tendons rubbing when you walk however it did not seem to help knee arthritis pain when sitting for long periods. At least that is my experience.