Lower Back, Hamstrings
Glutes, Core
Watch Tutorial
https://www.youtube.com/shorts/7cpldMZjLOs
https://www.youtube.com/shorts/sAAn3y-qxP4
Bar on upper back.
Stand feet shoulder-width, knees almost straight (stiff).
Back straight, chest up.
Hinge hips back, lower torso towards parallel floor.
Keep legs stiff.
Feel hamstring stretch.
Return extending hips.
Repeat.