Deadlifts are the ultimate lower-back exercise, and, if done correctly, they can decrease back pain, decrease the risk of injury and improve functional strength. Proper form is essential for deriving strength benefits from deadlifts, and it's important to work within your skill level and ability in order to avoid injury.
Benefits of Deadlifts for the Lower Back
In "The New Encyclopedia of Modern Bodybuilding," eight-time Mr. Olympia Arnold Schwarzenegger describes the deadlift as the ultimate exercise for the back of the body, from the hamstrings all the way up to the traps, and especially the lower back. But deadlifts build more than just the visible lower back muscles. The book "Strength Training Anatomy" explains that deadlifts work in a practical way to protect the lower back by developing the entire core. A study published in the January 2008 issue of the "Journal of Strength and Conditioning Research" found that deadlifts work the abdominal muscles more than ab-specific exercises. The lower back muscles alone aren't enough to prevent the spine from folding forward beneath the stress of a lift such as the deadlift. Instead, heavy deadlifts activate and strengthen the entire girdle of core muscles, creating internal pressure that immobilizes the spine. This is unique to very heavy exercises such as the deadlift and squat, and is essential for creating the strength to prevent lower back pain.
Disadvantages of Deadlift for the Lower Back
Conversely, if you use improper technique during a deadlift, you can injure your lower back and create chronic pain. The biggest danger is allowing your back to bow forward. The spine is placed under tremendous stress during a heavy deadlift, and if you lift with correct form, that stress is distributed among the vertebrae. However, if you round your back, the vertebrae at the top of the arch receive a disproportionate amount of strain and can easily herniate. Even if they don't herniate, the flexion creates pressure that can impact the nerves running through the vertebrae.
To ensure that deadlifts improve your lower-back health, you must perform them with perfect form every time. To properly perform a traditional deadlift, squat down to a barbell and hold it with a shoulder-width grip. The outside of your knees should be pressed against the inside of your arms. Activate your core, expanding your abdominal muscles. If you have trouble feeling this, wear a lifting belt. Your abs will press against it as you deadlift. Drive through the heels as you straighten the legs. This is important, as rocking forward onto the toes places tremendous stress on the lower back and the knees. To balance, your toes should stay on the ground, but no force should go through them. Never allow your backside to rise up without your shoulders also rising. This places stress on your spine. Once you're standing upright with the barbell, follow the same path to set it back down.
If you suffer from chronic pain in your lower back, talk with your doctor about an exercise regimen. Deadlifts may not be for you. Even if you have a healthy back, start slowly. Perform sets of five reps. As you progress, you can perform lower-rep deadlifts routines occasionally, but wear a lifting belt when attempting a new max. Most importantly, if you can't perform a lift with perfect form, give it up. Unlike many other lifts, it's not possible to cheat a deadlift safely for even a single rep.