Shelf perches are a great addition to any bird cage or aviary. They offer a great landing zone if your bird is flighted and can be placed not only on the cage but in different areas in any room in your home.
Shelf perches are also useful in maintaining the health and dexterity of handicapped birds having issues with a single foot. A shelf perch allows them to rest without having to constantly use their one good foot.
A customer writes
My blue/gold macaw has arthritis in his foot. Is there anything he can take for discomfort ? He was diagnosed by an avian vet in Dallas. She said it would get worse. Annette R.
Medically there's not a lot I can do but I can make some suggestions regarding a change in your birds environment. Your bird has a zygodactyl foot - a bird's foot having the first and fourth toes of each foot directed backward and the second and third forward
In perfect conditions the foot naturally wraps around various size perches that emulate tree branches. Keyword here being "round" Because of the arthritis your bird has lost and will continue to lose its ability to grab perches for extended periods of time.
The first thing you want to do some move things around in the cage to make the more "wheelchair accessible" so to speak. Move toys and food dishes lower in the cage perhaps keeping one or two treats higher as incentive to exercise.
Two or more flat perches would be very helpful
There will be trial and error on your part but you'll find your bird very adaptable - Best of luck
Windy City Parrot