Sandy Goetz was one of my neighbors and not only a friend, but she was my assistant for awhile until she was hiring me to do the carpentry and finish work on some of her own commissions. Her home had a spiral staircase that had no center post and was actually partially supported by a cable through the railing. Well, as happens with wood, it changes over time and so it got loose to the point of feeling very unsafe, actually. So, she asked me to fix it and the best solution I could come up with was to make a bracket that would secure the railing to the wall at one point and stabilize it. That bracket had to be strong enough for an adult to come down the stairs fast, such as in an emergency, and to also handle children running up and down it.
The process was to figure out a structure that would be strong enough to easily do what was needed, and to make a mounting for it that would not fail. So, I made a rough wax model that filled the space between the wall, minus the thickness of the bracket, form it to fit onto the railing, shape it into something attractive, and yet fully functional. there was a lot of preliminary work, trial and error sort of thing, but I did come up with the bracket you see above and in the pictures below. The mounting pad was chosen from some figured Oak that I shaped to fit the bracket and mount onto the wall securely. The shape of the bracket was refined over time and came out as you see.
From the bottom of the stairs, looking up
A close up picture of the bracket
From above looking down