Choose the appropriate barbell weight matching your fitness level. Grab the barbell using an overhand grip, shoulder-width apart. Take an upright stance, holding the barbell, with your feet a little less apart than shoulder width and toes forward. Fix your torso and do not over bend at the waist.
From the starting position move your pelvis backwards by flexing your hip joints, not changing the bend of the spine. Move your pelvis backwards and simultaneously make a deep bend forward so that the firmed up spine is parallel with the floor. Keep your crus (lower legs) fixed perpendicular to the floor throughout. Hold the barbell as close to your legs as possible. Complete the movement by pushing your pelvis forward without changing the spine bend and keeping your pelvis in a neutral position. Inhale in the starting position and while going down. Hold your breath and fix your torso throughout the entire movement and then, when you are back in the starting position again, exhale and start another repetition inhaling again. Do the required number of repetitions using the same technique.
Make sure your body is in the correct posture, fixing the torso, keeping your pelvis in a neutral position and eliminating lordotic swayback at the waist. Your shoulder blades point down and towards each other.
Keep your knees in the direction of your toe tips throughout the entire movement and avoid swinging them in either direction when you overcome the resistance. Also make sure your knees when pointing forward and do not cross vertical plane of your toes and keep them perpendicular to the floor throughout the entire movement. Keep your heels on the floor at all times. Do not overestimate your abilities when choosing the weight. Avoid moving your arms upwards as only your hands are needed to grab the barbell. Take account of your breathing when doing this exercise and avoid dynamic motion.
Stand with your side to a mirror and watch if your technique is correct. When choosing the weight, put much emphasis on perfect technique. If doing the exercise incorrectly, lower back injuries may occur and that is why it is important to use correct technique and a correctly-activated internal stabilization system.
Lift the barbell to the starting position. The legs should be somewhat closer to each other than the shoulder width. Use overhand grip and start the movement by moving the hips backwards.
The barbell should be lowered as close to the body as possible. This is the difference between the Romanian deadlift and stiff-legged barbell deadlift: in the later you do not move your hips backwards but only lower your upper body with legs slightly bent in your knees. The barbell is thus further away from your legs when lowered.
Both exercises can be done on a platform so that the trajectory of the movement will be longer.
Do not lower your back forcefully. Do not round your back at any stage of the movement. Do not lift the barbell fast and do not use explosive force in this exercise.
Also, do not hit the floor with the barbell and do not bounce back – all such movements can cause severe back injuries.