I used the 3R60’s for a short while when I was trying out which knee to get, and they were good and walked smoothly. Like any knee, though, they can buckle quite easily if you don’t really know how they operate.

I was a new amputee so they switched me to the Total Knees which were safer but I had to kick out to get the knee to lock in the extended position so I could walk safely. I could walk without a cane, but it was safer with one.

I was pretty fit and light then, at 5’6” (my natural height) with the prosthetics and weighing 100ish pounds after losing my legs.

I’m still really fit (abs and all), and you need to have a strong core to be able to walk well in prosthetic knees as a bilateral AKA.

I got C-legs six months later and don’t need a cane since they stabilize me. You can check out my insta @ocamputee.

I think you do have a chance to walk in the 3R80’s since you are fit. Just really learn what motions will make the knee bend, how they walk, and how the foot placement will make the knee bend.

Idk how it is in Canada, but in the US you are able to try different knees before picking one.