Stiff-legged dead lifts

  This movement is a tremendous overall muscle developer and is also the single most productive exercise for the muscles of the lower back, referred to as the erector spinae muscles, which, as the name implies, act to keep the spine erect.
  To perform the movement properly, stand erect with your feet just under the barbell. Then, by bending your knees, grasp the barbell, with your hands a little wider apart than shoulder width and your knuckles facing front. Now slowly begin to stand erect, straightening your legs as you do so. Keep lifting the resistance until you’re completely erect and the bar is in front of your thighs. Now slowly lower the resistance until it is back on the floor, and repeat the movement for the required number of repetitions. Rest briefly, and then move on to your next exercise. Be sure to draw your shoulders well back at the completion of the movement in order to involve the trapezius muscle, which slopes down from your neck to your upper shoulders.