A problem I have seen more often with most deadlifts is hyperextending at the end of the movement. A lot more athletes, when they first train with me, have this problem. I think they do it because that is how they think the movement is supposed to be done and haven’t been shown the correct way and don’t know any better or they have a weakness. I often ask “do you get a sore back when you deadlift?” and 9 times out of 10 the answer is yes.
When you finish a deadlift you want to drive your hips forward as explosively as possible, finishing the movement by squeezing your glutes as hard as you can, with your hips fully extended, and your shoulders slightly in front of the bar. The problem comes when athletes are unable to drive with the hips and contract the glutes, they hyperextend their lower back to finish the movement instead of contracting glutes. They are actually very weak in the finished position, if you poke the butt it is soft and they often have a slight bend in the knees as well. All the load in this poor position is transferred to the low back.
Now this won’t necessarily cause an immediate injury but over time you will definitely develop one if you continue to hyperextend at the end of the deadlift. It is like tooth decay, you don’t feel it happening but you know it once you have a hole in your tooth.
If it is a bad habit that someone has developed then it is a matter of making them aware of the problem and just teaching them to stand tall, not lean back. You can give them a slap on the back once the hips are fully extended to let them know they are there. This doesn’t take very long to teach once they feel how much more solid they are in the end position and especially when they realize how much energy they were wasting before.
I like to teach my athletes to finish their deadlifts with the shoulders slightly forward for a couple of reasons. First of all is so they don’t overextend and ruin their lower backs, as spoken about above, and I also like them to finish in this position so that it teaches them a good position for when we do more explosive movements like snatch pulls, clean pulls, power snatches, power cleans etc. In these movements you don’t want to purposely drive your hips under the bar, you want your shoulders slightly in front of the bar until the point of contact where you explode.
A small change in technique like this could save you from injury and also increase the amount of weight you can lift. If you have to regress a little to get your technique right I suggest you do so it will be we worth it in the long run.