The three types of rotation exercises that can put you into the danger zone with respect to your lower back include those done on the seated, twisting machines that are supposed to “strengthen your trunk,” seated and standing twists done with a dowel or broomstick and an old-time machine in which you stand on a plate or disk that rotates and you twist the disk left and right while holding onto a stabilizing bar.  I’ll start with the more recent twisting machines.
 
The various apparatuses found in gyms today put you in a seated position.  Your arms may be braced in a variety of ways, but the outcome is always the same.  The point, you are told, is to rotate to a full range of motion against resistance while you’re seated on the machine.  The movement, supposedly, is “strict,” and the isolation will “strengthen the oblique muscles and get rid of your love handles.”  The reality is that this kind of maneuver can cause an injury serious enough to require surgery and alter your training schedule permanently.

When you sit in these machines, your pelvis is in a weight-bearing position; that is, it is supporting the weight of your upper body against the seat of the machine.  Because of this the pelvis cannot rotate with the spine as it is supposed to do naturally.  Since your arms and back may be braced, depending on which machine you’re using, the rotational demand is on your lower back, and it is excessive.  This creates a shearing force on the disks of the lumbar vertebrae.
 
The outer, fibrous layers of a disk can begin to fray or tear, and the torque can increase the tear to the point where a portion of the center of the disk protrudes beyond its normal boundary.  This is a pathological condition known as a disk protrusion or prolapse, depending on how severe it is.  The old lay terms for this injury are a “slipped disk” (even though nothing actually slipped) and a “ruptured,” or “herniated,” disk.  If there is enough damage and inflammation of the disc, you will suffer the inevitable pain, but you can also experience muscle weakness, numbness, tingling and/or loss of reflexes from the inflammation of the major nerve.  In a few cases these symptoms could require emergency surgery.  Unfortunately, we recently had patients coming to the Soft Tissue Center who were suffering from a sudden onset of symptoms that were so severe that we referred them to a neurosurgeon.  We discovered that these patients were using seated twisting machines when they first experienced the symptoms.
 
The lumbar vertebrae are identified numerically from top to bottom as L1 through L5.  The highest vertebra in the pelvis is known as S1 (where S stands for sacrum).  The general pattern of this type of shearing action reveals that the greatest stress is to the disks that lie between L5 and S1 and between L4 and L5.
 
As you’ve no doubt noticed in the gym, the standing or seated twist with an dowel is frequently done with high intensity and velocity, which contributes to the problem.  While the seated twist is slightly less volatile than the machines, it can still put you in the same situation.  Don’t do it.
 
If you don’t perform the exercise with such high intensity and so it does not create the same degree of shearing force on the disks, it can still weaken the outer fibrous walls, leaving you with what is virtually a time bomb that can explode at any time that stress or torque is applied to your lower back.  It is routine to hear bodybuilders, wrestlers, football players and recreational athletes who perform very strenuous exercises describe in our office how they were putting on their socks---or something equally simple and seemingly innocent---and their “back went out.”  The stories are repeated time and time again: “I was putting on my pants,” “I was just pulling some weeds,” “I pulled out my dresser drawer,” “I was just shaving,” “I reached into the backseat,” “ I reached into the trunk for the groceries,” “All I did was raise the toilet seat, and bam! My back went out.”

These stories come from all walks of life, including strength athletes.  You don’t have to contribute to the likelihood of a lower-back injury by falling prey to yet another gym myth that will weaken the area.  And make no mistake about it---the twist is not a good warm-up for your lower back either.
 
The above discussion applies to those of you who have not previously experienced low-back symptoms.  If you already have lower-back problems, you are playing with fire when you include this exercise in your workouts.
 
The fact that you may be standing rather than sitting is no reason to think that you’ll be safe from injury if you do twists.  While it’s true that your pelvis is not pinned against the seat in the weight-bearing position when you do standing twists, the movement still involves the same degree of rotation and results in the same shearing action of the lumbar disks.
    
There are a few other activities in the gym or even around your home that you should avoid in order to decrease your risk of lower-back injury.  For example, when you pick up a weight to lad a bar, face the weight and pick it up.  Do not rotate to lift it.  A certain 275-pound offensive guard was loading the bar on the bench press one day.  He was standing by one end of the bar, looking for 45-pound plates, when he saw what he was looking for off to his side.  Without moving his feet to face the plate, he twisted and bent down to pick up the plate.  Much to his surprise, his training partners were soon picking him up off the floor because he couldn’t move due to excruciating lower-back pain.
 
This football player could squat more than 450 pounds for reps, and he could clean nearly 400.  His back was strong.  Even so, the lumbar disks were not designed to be rotated to that degree, especially under a load.  The patient’s strength is simply not a factor if that type of stress is placed on the lower back.
 
Always face what you have to pick up or lift.  Do not twist and bend to get it—not matter what.
 
Several years ago a top bodybuilder advocated an exercise in which he was lying on his side hanging of a hyperextension bench.  He would lower himself toward the floor, and it was almost like a type of side bend, since his thighs were on the bench and his feet were stabilized by the footrests.  As he lowered himself, he would rotate his upper body so that it faced the floor.  In addition, he held plates in his hands when he did this.
 
I hope that by now, you can imagine this movement’s tremendous potential for injury due to the rotation and resistance that are applied to the lower back.  Avoid this exercise at all costs.  There are safer ways to train your abs, and there are safe ways to reduce your bodyfat by dieting.
 
Remember that not all the exercises you see performed in the gym are beneficial.  Even more important is the fact that there are a few exercises that are actually harmful and can alter forever your ability to train.  Train smarter---not just harder.