The Smith machine is a piece of strength training equipment with a sliding barbell that glides up and down on metal cylinders. It was invented by Jack LaLanne in the 1950s and is a staple in most gyms. Depending on the fitness level of the exerciser, the bar of the Smith machine can be used alone or with barbell plates for more resistance during single and multi-joint exercises. Some gym-goers may use excessive loads, faulty posture and poor biomechanics while using the Smith machine, resulting in a contraindicated exercise. Consult a certified fitness professional to learn how to use the Smith machine properly.
There are many lower-body exercises that can be performed on the Smith machine, such as squats, lunges and calf raises. Excessive loads and improper foot placement can alter the movement patterns of all three exercises. To prevent injury, choose a resistance level that allows you to do 12 to 15 repetitions. The last few should be challenging, and you should still be able to maintain good form. For squats and calf raises, stand with your feet lined up shoulder-width apart and avoid placing your feet in front of the bar. During a lunge, make sure your front and back leg are evenly spaced apart. The bar should rest on the back of your shoulders to prevent strain in the neck and upper back.
Forward Flexion Exercises
A deadlift targets the hamstrings and bent-over row focuses on the middle back muscles. Both exercises involve unsupported forward flexion, which has been termed contraindicated, but is a necessary functional movement. Using the Smith machine can potentially make both exercises high risk when poor posture and heavy resistance are involved. Taking the cue from the lower-body exercises, use a weight that you can effectively move without strain. For both exercises, your knees should be slightly bent and your back should be flat when you hinge from the hip. Engage your core muscles to support your lower back.
Thousands of bench presses, triceps extensions and shoulder presses are performed daily on Smith machines, keeping physical therapists busy nationwide. The use of a straight bar during these exercises compromises the range of motion and puts a lot of strain on your shoulder joint, especially if too much weight is used. For bench presses and triceps extensions, ower the bar until it is about 4 to 6 inches away from your chest to prevent injury to your shoulder girdle. Perform shoulder presses standing to minimize stress on your lower back during the initial lift-off and keep the bar in front of you to avoid excessive external rotation.
Dumbbells Are Smart
The last two exercises that are commonly performed incorrectly on the Smith machine are biceps curls and upright rows. The straight bar and vertical movement of the machine are too restrictive for elbow flexion, even with light resistance. A pair of dumbbells are more effective to strengthen the biceps. The upright row is another upper-body exercise that can be stressful to the shoulder complex. Lateral, reverse and anterior raises with dumbbells are safer alternatives for the deltoid muscles. Make sure you warm up before any strength-training routine, stretch all major muscle groups afterward and stop whenever you feel pain or discomfort.