When done correctly, deadlifts are an effective exercise to improve functional hamstring strength and definition. But tight hamstrings can cause you to make key biomechanical errors in execution that can lead to low back pain or injury. Understanding the mechanics of deadlifts will help you tweak your technique while daily stretching will improve your range of motion.
Your hamstrings are part of a group of muscles called the posterior chain, which involves the extensor muscles of the spine and the hip extensors. Together, the posterior chain muscle groups produce force at the hips and stabilize the spine. Your hamstrings are a group of three muscles that, like the quadriceps, cross over two joints, the hip and the knee. Your hamstrings are responsible for knee flexion and work with the gluteal muscles to extend the hip. When your hamstring muscles and tendons are tight, they affect both the knee and hip joints. But as part of the posterior chain, tight hamstrings can also affect the spine.
Deadlifts are intended to work the hamstrings, but poor execution forces you to use your back muscles instead. Common mistakes include locking the knees, rounding the spine, moving the bar away from your center of gravity, and trying to bring the bar lower than your body structures will safely allow. These errors place stress on the lumbar spine. Locking your knees with tight hamstrings decreases your potential range of motion at your hips. Rounding your spine shifts the workload to your erector spinae muscles and away from your hamstrings. Bringing the bar too low will force you to round your spine. To improve mechanical leverage, keep the barbell close to your body so that you shift the workload from your low back to your legs.
To execute a deadlift with minimal back strain, begin in an erect position. Plant your feet hip-width apart and bend your knees slightly. Contract your abdominal muscles. Grip the barbell directly beneath your shoulders, lift your chest, and pull your shoulders back and down. Fix your gaze on a point in front of you. Maintain your starting spinal alignment and forward gaze as you hinge forward from the hips, allowing your knees to bend slightly. Keep the bar close to your body. Do not allow your back to round. Go as far as your hamstrings will allow without rounding your spine, then contract your hamstrings and gluteal muscles and return to your start position. Over time, you will be able to hinge farther forward as your muscles and tendons become more flexible.
Injuries and Range of Motion
The Sports Injury Bulletin lists disc prolapse/degeneration, facet joint sprain and nerve damage as some of the spinal injuries that can take place because of poor exercise mechanics and muscle imbalances. According to the American Association of Orthopedic Surgeons, tight hamstring muscles are more vulnerable to muscle strains during sports activities. To prevent injury to the hamstrings and low back, athletes and weightlifters should stretch hamstring muscles daily.
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This article reflects the views of the writer and does not necessarily reflect the views of Jillian Michaels or JillianMichaels.com.