Why You Should Avoid The Smith Machine
Machines are never superior to free weights. Never. Ever. I’ll say it again….Never. And the Smith machine is the worst of the worst. Yes, I know your trainer or your best friend told you that the Smith is a wonderful thing, and one of the most functional and safest pieces of equipment in the gym. They may have even told you to stop using free weights and to use the Smith because it's safer. They’re dead wrong, and I'm going to tell you why.
1. Pattern Overload Syndrome: The Smith machine locks you into a fixed plane of motion, which can lead to what is known as 'pattern overload syndrome'. The more fixed the object, the more likely you are to develop a pattern overload, and the Smith follows an extremely fixed pathway. This fixed pathway repetitively loads the same muscles, tendons, ligaments and joints in the same pattern, encouraging micro-trauma that eventually leads to injury. If you always uses a Smith machine for your bench presses, you end up working the same fibers of the prime movers in the bench press all of the time: triceps brachii, pectoralis major, long-head of the biceps brachii, anterior deltoids, and serratus anterior. You can't change the pathway; the bar will always be in the same position. This commonly leads to chronic injury over time.
2. Reduced Stabilizer Training: The weight is stabilized for you. However, joints normally operate in multiple planes, and recruit a myriad of other muscles to help stabilize load. Use of the Smith machine greatly decreases this stabilizer activity. This creates a problem when translating your strength and muscle gains back to real life. If you have not trained the stabilizing muscles, you create size and strength imbalances in these muscles that would normally be assisting in the lift. In addition, having weak stabilizers will serve to shut down the prime movers before the prime movers are ready to shut down. If the stabilizers cannot maintain joint integrity there is a feedback mechanism that will cause the prime movers to shut down, or “fail.” When you’re helping your buddy lift that heavy piece of furniture, or pulling that heavy sack of groceries from the back seat of your car, it won’t be attached to a bar that assists your move and travels in a straight up and down plane of motion.
3. Compromised Center of Gravity: When you squat with your knees out in front there is added pressure on the spine. When you free bar squat, the path of the bar is traveling over the instep of your foot and you are driving through your natural center of gravity (COG), the COG you create by moving your hips back and bending your knees on the decent of the squat. When you are on a smith machine with your feet positioned out in front, you are causing your body to drive through a false center of gravity. Now, instead of the weight being over your feet, it is directly in-line with your spine and your feet are out front, placing your new (false) COG somewhere about mid thigh. The problem this poses is that your spine is not in a healthy position to stabilize force. Your hips are there not only to move the lower body, but also, to stabilize forces being placed on the body. If you put them out front you take that ability away from them causing all of the weight to be compressed on the spine without anything to absorb the shock. NOT GOOD!
These principles clearly apply to any exercise you might want to do on the Smith. Take, for example, the squat. Because of the mechanics of the knee joint, the body will alter the natural bar pathway during a free-weight squat to accommodate efficient movement at the knee. A fixed bar pathway doesn't allow alteration of the plane of motion for efficient movement of the joint, thereby predisposing the knee to harmful overload via lack of accommodation. And, for all of you that like to put your feet out in front of you, in addition to the COG problems outlined above, if your feet are out in front of you, you tend to push back against the bar. Doing so changes the function of the hamstrings role in the move, removing it’s stabilizing, protective effects on the knee joint. The result is an increased sheering force on the knee. Again, over time, chronic injury, and even possible traumatic knee injury.
So. Now that you’re armed with the facts, you know to stay away from the Smith (actually any machine that locks you into one plane or arc of movement, but we’re taking about the Smith here). Do yourself a favor and get acquainted with the barbells and dumbbells this fine establishment has to offer.