If you can, try to have a spotter assist you during this movement.
Center region of your back, spanning from the pelvis to just below the neck. However, parts of it are hidden beneath other muscles. The lower portion is the most visible.
Muscles of your butt.
Muscles spanning the back of your thigh.
Barbell
Make sure to always use weight clips whenever you use a barbell, to prevent the plates from sliding off.
Flat Bench Without Rack
If you can't find this bench, consider using a flat bench with rack instead. If your exercise requires you to use a barbell or bar, you cannot substitute. If you do not need to use either, you probably can substitute.
Exercises that target the same primary muscle groups and require the same equipment.
Exercises that target the same primary muscle groups with different equipment