You are the mercy of the people performing the installation. Grab Bars need to be secured into the structure of the house, like a stud, or use new technology that has been tested and proven to hold the weight of human beings when they’re holding on and moving quickly. The grab bar and the way it’s installed may the only sitting between you and a future catastrophe!
Use trained installers who work as part of a team to not only get the bar where it is needed, but also have the knowledge to make sure that it stays where it is needed.
Thanks and have a great day!