Behind the neck shoulder presses are not that common anymore, but once in a while I will see the occasional novice attempt these lifts. Loading the shoulder with the hands behind the heads puts an extreme amount of pressure the shoulder in an externally rotated position which increases the chance for injury of the rotator cuff muscles.
Instead Do: Seated Dumbbell Presses
Seated dumbbell presses work the same muscles as the behind-the-head variation with considerably much less stress to the rotator cuff. When doing them be sure that you do not arch the lower back, and also do not lower the weights so far that the elbows drop under the level of the shoulders.
2) Straight (Stiff) Leg Deadlifts
Stiff-leg deadlifts can be a great lift for an experienced lifter trying to build strength in the hips, glutes, and hamstrings. Most people however are not experienced lifters, even if they like to think they are. If done improperly this lift can put a lot of pressure on the lower and middle bac and increase the risk of pulled muscles and slipped discs.
Instead Do: Stability Ball Hamstring Curls
Stability ball hamstring curls rank among the most hated exercises among my clients, and for good reason. They are tough! In addition to working the back extensors, hip extensors, and glutes, the stability ball also adds an element of core control that the stiff leg deadlift does not. When doing this lift, take your time, don’t try to rush through it or you won’t give your body a chance to learn how to stabilize itself properly.
Another “back killer”, good mornings, are a complete mystery to me. Whoever thought to themselves “hey let’s put weight on our backs and bend at the waist” must have had a screw loose. Aside from a rehab application for a very specific cause where I would use VERY little weight, I do not see the benefit of risking a good morning because it may lead to a very bad night.
Instead Do: Back Extensions on Stability Ball (or Roman Chair)
Back extensions can be a great way to strengthen the lower back postural muscles, as well and to increase gluteal and hamstring strength. Whether you decide to use a ball or a roman chair, be sure not to over extend when coming up as you can cause increased pressure on the lower spine.