You can resize the display of a skeleton’s joints. Increasing the display size can make the joints and their bones easier to select. Decreasing the display size can make other objects such as flexors easier to select.
To resize joints in the scene view
You can also set the size of joints from Windows > Settings/Preferences > Preferences, and then select Kinematics in the Display category.
The percentages are relative to the default setting, which is always 100% or 1.00.