Stabilizers vs. Prime Movers:
Understanding How to Strengthen Your Back and Avoid Injury
Watch most people do deadlifts, squats, or even bench
presses, and you are watching a back injury in the making. The reason? They
are using their stabilizers to move the weight. When they do that, the
stabilizers are not free to keep the back stable and neutral. This allows
the back to float. Further complicating matters, this also exhausts the
stabilizer muscles so the back is in jeopardy long after the exercise is
This begs the question, "What muscles are the stabilizers
and which are the prime movers?"
Ask a trained clinician this question, and you are likely to
get back an answer with the clinical names of the muscles. Probably, this
would be of no practical value to you. So, here's a more useful way of
looking at it:
Stabilizers are the muscles that keep your back in alignment. The are also the muscles that hurt when you lift a weight with your back rounded. But which muscles are these, exactly? They are the small muscles of the lower back and the central spine.
Prime movers are muscles that aren't attached directly to
the lower back or the central spine. They are large, because their job isn't
to hold the small bones of the back in place but to provide locomotion.
Viewing this in a slightly different way, the stabilizers
are the muscles that hold things in place and the prime movers are the
muscles that move things. The stabilizers can be misused to move things, but
that takes them out of the stabilizer role. The prime movers can be used
only to move things.
Now that we have this understanding, what does in mean in
practical terms when designing or performing an exercise? Here are some
basic rules derived from this:
Keep the back neutral. Don't arch or bend the back to gain leverage in lifting. If you are training with weights, this defeats the exercise--so, no purpose is served. No matter the reason for lifting, bending the back to aid in the lift will strain the stabilizers.
Think leverage. Think of your body as a collection of
levers. What are they prying against? If you are performing an exercise such
that the force centers on your stabilizer muscles, your form is wrong.
Keep the stabilizers strong. But wait--if you're not
supposed to lift with them how can you strengthen them? Easy. Bad posture
lengthens the stabilizers, which weakens them. Practice good posture, and
you have stronger stabilizers. They get plenty of exercise just doing their
That "normal job" of stabilizers doesn't mean they never get
any hard exercise. When you do your core exercises, you give the stabilizers
additional work. You keep them from overworking by adhering to two
Use good form. We touched on this, earlier. In addition to the proper mechanical techniques for lifting, practice the proper breathing techniques. Don't suck in your gut--instead, let it relax while you take in a deep breath of air. Then, contract it a bit as you lift. This properly pressurizes the abdominal cavity, creating a sort of internal weight belt.
Don't overtrain. You can't do core exercises all the time.
Because they are so exhausting if done correctly (see our
intensity article), you need long rest periods
between them. That's one reason, for example, you get better results from
doing squats twice a month than from the often-used "total body three times
a week" method that is suitable only for physical therapy or for adding to
gym profits by taking away the progress that keeps you using the gym
membership you paid for.
Of course, this isn't the whole story on back pain prevention.
But it does address a very common cause of backpain among people who exercise to
prevent that kind of thing.
For more information, get the Lose the
Back Pain Video.