Barbell good morning:
Stand with your feet shoulder-width apart. Place a barbell of appropriate weight on your shoulders. If you're just starting with the exercise, begin with light weight. The bar of the barbell should rest on your trapezius muscles of the upper back near your shoulders. Brace your abdominals and take a good breath in. Exhale as you bend at the hips until your hamstring muscles start to limit your movement. From here, you can bend a little further to give them a stretch, but not so far that you feel pain or discomfort. Remember to keep your back straight. Your knees can bend slightly to relieve pressure, but you don't want to be in a squat. Inhale and focus on maintaining a straight back. Keep the arch of your lower back tight as you would when lifting from the floor. Exhale. Make sure your head and chest are up and forward. Check that you aren't curling your back forward. Inhale smoothly as you return to the starting position.
Mistakes and Recommendations:
Lift your torso only with the effort of your buttocks and the hip biceps. Do not try to lift the torso, unbending the lower back, and do not round your back, leaning forward.
The main involved back muscle is the extensor muscle. Do not relax it, since it fixes the natural back position.
Start with an empty bar. Add plates only when you feel that the lower back has become stronger.
Be sure to slightly bend your legs slightly in your knees in the initial position. This will make your position more stable.
This exercise helps you to stretch the back thigh muscles. You may combine it with the squats, lunges, leg presses and deadlifts.