The deadlift is one of the most beneficial lifts to develop synchronization of the lower and upper body. It aids in developing force through the lower body that improves athletic abilities such as running and sprinting. The deadlift taxes the whole body, it's the movement behind the squat that everyone should be doing. There I said it, with the amount of benefits that the deadlift provides, it is paramount. Many are cautious to deadlift because of either prior experience of feeling or hurting a lower back in the process or from some other article that said they are bad for your back without an explanation. So let's change that.
Done wrong the deadlift can cause problems for the body (just like the squat) when we are moving our whole body through space we need to be aware of where we (our bodies) are in space, if not, that is potentially when injuries can occur. This is where many are steered away from the deadlift because they have performed the lift incorrectly and gotten negative feedback from the body, and maybe even repeated the same movement in the same position for some time. But what they need to do is re-pattern the mechanics of the movement to create stability through the system so they do not get pain or tightness.
Proper setup can still lead to improper mechanics
The deadlift is different for people because there is no eccentric activity (lengthening) to load the system, the body has to start in an isometric position, produce force and turn it into a concentric movement. This can be challenging for the body because it wants to anticipate and adjust for the weight in the eccentric phase of a movement so it can then provide appropriate force to move the object/weight in the opposite direction. Taking the eccentric out of the equation the body has to learn to find and keep tension and produce force from that position. All while maintaining correct body posture to ensure system synchronization and lift mechanics. As the pull off the ground initiates, the body will go into sympathetic overdrive to move the weight off the floor and as this occurs the back will extend first and the abdominal and glute relationship will be lost and as the weight is lifted off the floor the lower back is doing majority of the work to pull that weight because position is lost through the thoraco- pelvis. With the loss of position comes compression of the lower spine, sacral joints, spine sacrum junction.
How to ensure proper mechanics
The exercise becomes more of a pulling exercise rather than a pushing exercise when we want the opposite. Yes you read that correct, I want the deadlift to be a pushing exercise. We want to push our feet through the floor, push our hips up and through to create force production. If we use it as a pull the glutes and legs do not act in the manner that will be beneficial to the person, or the person's sport/activity. To turn it into a pushing exercise we have to be aware of what our bodies are doing in certain positions and as we move.
Starting at the floor is critical for stability of the deadlift if we cannot sense the floor then we can get into trouble. Our feet ground us and make us aware of left and right, for the deadlift we want to feel the heels into the floor, the mid foot into the floor and the toes into the floor and press down. Now moving up to the hips is where we need system integration from above to help the trunk move as one, we need the ribs in an exhaled (down) position with a slight-slight posterior tilt (tuck) of the hips to set the canister and protect the lower back from turning on. The biggest part of this lift comes next and that's managing the air pressure that gets created when we get into positions and lift objects. With the ribcage and hips in the correct position this will create an increase of pressure in the system, the next inhale will try and break the position we have just created. So while maintaining the position above inhale slowly through the nose and feel the position maintained, on the next exhale push through the floor and push your hips forward and up using your glutes to complete the lift. This ensures that the lower back cannot activate because the abdominals in front are keeping the hips in the correct position thus allowing the glutes to function properly.
Progression to work on position of the deadlift
Feet are hip width apart on the floor,
Exhale and feel the ribcage go down and abdominals engage
Slightly Tuck you hips under, feel your glutes engage
Move hips backwards keeping the position of the ribs and hips and the muscles activated
Hold Position and PUSH through the feet as hard as you can for 10s
Repeats for 3-4 cycles
The above technique can be done prior to a lift, whether it's barbell, trap bar, or Kettlebell, have the hands on the bar or handle and PUSH through the floor as hard as you can and maintain hip and rib-cage position.