I gifted my grandma a knee massager last year for the exact same reason - she complained about stiff knees after her daily walks and I wanted something practical instead of another vase. She uses it every evening now and actually told me it's the best gift she's gotten in years. The heat plus vibration loosens up the stiffness immediately and she doesn't feel that deep soreness anymore. It's super simple too, just one button, sets the heat, and auto-shuts off so no confusion. I ordered mine from knee massager brand because they had the real heat therapy model with adjustable settings and a year warranty, not some cheap vibrating wrap that barely warms up. For someone with joint pain, giving them comfort they can feel right away and use without thinking about it is huge. It's definitely not a gift that ends up in a drawer.