Some gyms don't have Power Racks. Instead they have Smith Machines which look like Power Racks, but with a fixed bar. Some people will tell you the Smith Machine is safer than free weights since the bar can't fall on you.
Well this isn't true. You can get injured using the Smith Machine. And although you're using a bar, it's a machine. Meaning you'll get subpar results compared to free weights. Here are 10 reasons you shouldn't use the Smith Machine.
1. False Sense of Security. You'll tend to take more risks on the Smith Machine because the barbell is fixed. Putting on weights you might not be able to lift yet since you can stop it more easily anyway.
2. Unnatural Movements. On a free weight Squat your body goes down in an arched path. Smith Machines force your body into fixed, unnatural movements patterns. This can cause injuries, especially with heavier weights.
New generation Smith Machines — like the Jones Smith Machine — try to solve the problem by allowing 3D movements, including front & backward movement. But they're still machines with drawbacks. Read on.
3, Knee Injuries. Knee pain from the Smith Machine is common. It forces your body into fixed movements patterns and places shearing loads on your knees. And it's hard to position yourself correctly under the bar.
- Feet Position. Feet too much under the bar: more knee flexion and knee stress. Feet too much forward: more knee stress because they want to slide forward and your lower back gets in a weak position.
- Hip Extension. You'll tend to lean against the fixed bar, causing less hip extension. Your hamstrings — knee stabilizers — will shut down. More shear force on your knees and thus more risks of ACL injuries.
4. Lower Back Injuries. The fixed bar tends to make you rest against it and the Smith Machine forces you into unnatural movements patterns.
- Lower Back Stress. You're pushing your spinal erectors & neck muscles more against the bar. More back stress, especially with heavier weights.
- Lower Back Rounding. Feet too far forward puts your lower back in a weak position and will tend to make your lower back round.
5. No Balance. The Smith Machine balances and stabilizes the weight for you since its bar is fixed. You won't strengthen your stabilizing muscles or improve balance & coordination. Things you need for daily activities & sports.
6. Less Strength. All exercises become easier and less stressful since the Smith Machine balances the weight for you. You won't get as strong. Expect to lift less weight when switching to free weights.
7. Less Muscle. If you aren't making gains: switching to free weights will often make you break that plateau. Free weights force you to balance the weight, making the exercise harder on your body. Bigger adaptive response.
8. Muscle Imbalances You only build strength in 1 plane since the bar is fixed. This causes muscle imbalances and increases the risks of injuries in the other undeveloped planes of movements.
9. Technique is Different. Common advice is to learn to Squat inside the Smith Machine before switching to free weights. The thinking behind this is that the Smith Machine is safer and helps with balance.
But it's a waste of time. Technique is different using free weights since you have to balance the weight yourself. You'll have to lower the weight when switching and relearn technique from scratch.
10. Less Potential. You can minimize some of the above problems. But even if you do, the Smith Machine remains less effective for strength and muscle gains. Instead of trying to minimize problems: do the exercises with most potential.
How to Increase Safety on Free Weights. Weight lifting has the lowest rate of injury. You'll prevent injuries by learning & lifting with proper technique. Read all the exercise technique articles in the left sidebar. Extra tips:
- Start Light. Control your ego. Start with light weights, focus on learning proper exercise technique and add weight slowly but gradually.
- Have a Spotter. Especially on the Bench Press. Your spotter should be there to catch the weight if necessary, not to lift the weight for you.
- Use The Power Rack. And set the safety pins so they can catch the weight. Read how to Squat if you don't have a Power Rack.
- Inverted Rows. Put the barbell somewhat lower than your belly height and use it for Inverted Rows.
- Pull-ups. Use the Pull-up bar of the Smith Machine or set the bar high and do Pull-ups from there with your knees flexed.
- Push-ups. Not strong enough yet for Push-ups? Put the barbell at belly height and do incline Push-ups. Lower the height as you get stronger.
For all other exercises: use the Power Rack so you can use free weights. If your gym has no Power Rack, consider building a home gym.