1 Finger
To balance well, your body needs to know where it is in space and what movements it is doing. Your body uses lots of sensory information from your eyes, your inner ear and proprioception to tell you where you are in space, where you are relative to objects around you, and what movements your body is doing.
What is the point of the 1-finger scenario?
Just lightly touching a stable surface can give your body a reference point of your environment. This is bonus sensory information that can help you understand where you are in space and usually boosts your balance when you are touching that surface.
Even though you can get a different score when you are touching a surface, the score without touching a surface is your fall risk. However, your balance score when you are touching a surface shows you the boost you can get to your balance when you are touching a stationary object, such as a railing.
Now you have seen how helpful a stable surface can be when moving around. If you need to use a cane or walker, use it while you work on your balance. When you have improved, revisit the need for a cane with your doctor. As you move in your daily life, hold onto handrails if you would like extra support - they are there to help you.