A few years back, I attended a seminar of renowned strength coach Charles Polequin. At one point someone asked a question about the Smith Machine, and how it might be useful in a strength training program. Coach Polequin’s answer: Whoever invented this thing (indicating Smith Machine) should be put in jail.
Charles Polequin is not known for his subtlety. He went on to explain how using the Smith Machine puts you at greater risk for injury. Wait, isn’t the Smith Machine supposed to prevent injuries? For those who don’t know, this is the smith machine:
People like the Smith Machine because it allows you to feel safe squatting and bench pressing heavier weight without a spot. The bar is fixed to slide along vertical poles at each end of the bar. Heck, I used to use this machine before I learned how bad it is for you.
The main reason using this machine is so ill-advised is because it does not allow for the body’s proper range of motion. It has you pushing the weight on a fixed plane of motion. Well, sorry, the body doesn’t move that way. Sit up and down from a chair — your torso/upper body naturally leans forward a bit as you lower your body mass toward the chair.
The body naturally wants to disperse any force you are carrying (be it your own body weight, bags of groceries, or a loaded bar across your shoulders) over as many joints as possible. In the case of the squat, you are using your hip, knee, and ankle joints (as well as your lumbar-pelvic complex) to lower and raise your center of gravity toward and away from the earth. I’ll post a video showing a proper squat and you’ll see that you can’t perform this same movement on a machine that is fixed along a vertical slide.
Remember high school physics? Remember the pulley system? The more pulleys you used the lighter the weight would feel. Using the Smith Machine puts almost all of the force at the knee joint. Because the plane of motion is fixed vertically, there is very little help from the hip and ankle joints. A proper squat would have the hip, knee, and ankle joints flexing and extending simultaneously, working to disperse the force, making it easier to perform the lift. The reason I most often hear as to why one uses the Smith Machine: I got bad knees. Hmm. Maybe your knees hurt because your using a machine that forces you to move in a way that your body wasn’t designed to move, placing unnecessary extra strain at the knee joint.
Another reason the Smith Machine sucks is because it does nothing to strengthen smaller, stabilizing muscles. So, keep using the machine to get your large muscles bigger and stronger without strengthening the stabilizers and eventually you will injure yourself. You are only as strong as your weakest link. You may not injure yourself on the machine but you just may injure yourself playing wiffle ball in the backyard or some weekend sport or activity you enjoy doing.
The last reason reason the Smith Machine sucks is because you’ll simply burn less calories. Because there is very little challenge to your balance, core, and smaller stabilizing muscle groups, you are simply involving less of your overall musculature and, therefore, burning less calories.
So, get off the damn Smith Machine before you hurt yourself.