This is a yoga staff or dowel. It’s really an old hanging rod from a closet. A curtain rod or broomstick will work well, too.
Tadasana with a dowel - stand up tall and take the shoulders back. Press the dowel into the back ribs. Keep the shoulders back and the backs of the upper arms moving down. Keep the sides of the waist back, so the low back doesn’t pop in - keep it tall.
