1) Common Practice:
- “ברוך” = bend knees 🦵
- “אתה” = bow 🙇🏼
- “ה׳” = straighten up 🧍♂️
2) The Arizal and others say not to bend your knees at all. Bow body at “ברוך” and then bow head at “אתה” 🚫🦵
3) Gemara says “bow like a stick, come up like a snake” meaning you should bow quickly an come up slowly 💨🐍