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Stiff-Legged Deadlifts on a Block Build Colossal Extensors |
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Written by Stephen E. Alway, PhD, FACSM
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Monday, 23 April 2007 |
The deep back muscles and especially the erector spinae group stabilize the vertebrae of the spinal column. They stabilize your torso to maintain proper positioning during your upper and lower body exercises. Weak erector spinae muscles will cause you to easily loose your balance and fall forward when you're doing heavy curls, presses or squats. In fact, most of the muscles of your body will indirectly achieve a better training effect if the back extensors are sufficiently strong to engage the spine in proper and stable positions. Deadlifts are one of the best means of achieving colossal back muscles.
The Musculature
Stiff-legged deadlifts strongly activate the three large muscles of the erector spinae group. When the erector spinae muscles on both sides of the vertebrae contract together, the vertebral column is extended (i.e., from a flexed bent-over position to an upright standing position). If only the left half of the muscle contracts, the vertebrae will be rotated to one side. The iliocostalis muscle is the most lateral of the erector spinae group. It runs from the ilium of the hipbones superiorly (toward the head) to attach to the ribs (costals).
The longissimus muscle is the middle muscle of the erector spinae group. It's a long muscle that runs the length of the back. It sits between the iliocostalis and the transversospinalis muscles. The spinalis muscle is the most medial and deepest of the erector spinae muscle group. Most of its muscle fibers run between small posterior bony projections on the vertebrae called spinous processes. They help rotate the spine (slightly), especially when contracted on one side at a time.
The hamstring muscles also strongly contract during the stiff-legged deadlift (although they are much less activated with the knees bent). The biceps femoris muscle is a two ("bi") headed muscle on the posterior thigh ("femoris"; the femur is the thighbone). The long head attaches to the ischial tuberosity of the low hip structure. The fibers of the short head begin on the lower one-third of the femur bone just above the knee and because they do not attach to the ischial tuberosity, the short head is not considered a "hamstring" muscle. Both heads of the muscle fuse into a thick tendon that crosses the lateral side of the knee joint to attach to the fibula bone (and some ligaments) on the knee.
The second muscle of the hamstring group is the semitendinosus. The semitendinosus muscle is part ("semi") tendon ("tendinous") and part muscle. The semitendinosus fibers attach to the ischial tuberosity and insert into a cord-like tendon about two-thirds of the way down the posterior thigh. The semitendinosus crosses the knee joint posteriorly to attach to the medial side of the superior part of the tibia (the large medial bone of the leg). Although both hamstring muscles flex the knee, because they cross the hip joint posteriorly, they become important extensors of the back, if the feet are fixed on the floor. Deadlifts from a block take advantage of the extensor functions of the hamstrings and the erector spinae muscles.
Deadlifts on a Block
Although this is a great exercise for thickening the erector spinae, this exercise is not for everyone! If you have a long upper body and a relatively short lower body, you will generate much more torque through your lumbar vertebrae and intervertebral discs than someone with a short upper body, long legs and long arms. This combination places you at a high risk for lower back injury, especially when deadlifting from a block. Nevertheless, a substantial population is architecturally suited to this exercise, and these people also appear to derive good benefit from it.
1. Before doing the exercise, spend a few minutes stretching your hamstrings, quadriceps and back. This does not guarantee you will never sustain an injury, but without stretching, your likelihood of eventual injury is high. If you have very poor flexibility (e.g., short and/or tight hamstring muscles), you should concentrate on stretching these muscles for several weeks before starting deadlifts from a block.
2. To begin, place a bar on a power rack (e.g., in a low squat rack), then load it. The bar should be about knee height. By starting the lift in this position, you will minimize the initial torques across the lower lumbar vertebrae.
3. Place a block of wood that's at least eight inches high under the bar. Step on the block and place your feet about shoulder-width apart and under the bar. Your knees should be bent and your middle back flat (not rounded). Grab the bar with a pronated position (palms toward the floor) and shoulder-width apart. Look up so your neck, back and thorax will "flatten" (extend), reducing shearing forces through the intervertebral discs. Slowly lift the bar from the rack (do not jerk the bar) by extending both your trunk and your knees.
4. After coming to a straight (erect) position, take a small step backwards from the rack to avoid hitting it during the exercise. Be careful not to step off of your block.
5. Look up and keep your eyes and head up from this point onward. Never look at the floor during the lift, otherwise the middle of your back will become rounded and this invites a serious injury by destabilizing the spine.
6. Lock your knees straight, then slowly lower the weight toward the floor. Flex at the waist but keep your knees straight as the bar descends. Drop the bar toward the ends of your toes rather than over the middle of your foot.
7. At the bottom part of the lift, the bar will reach the level of the end of your toes. The plates on the barbell should not quite contact the floor and you need to make sure the block is high enough so that you do not bounce the weight on the floor.
8. Immediately start up to a standing position as before, by looking up and extending your back as you come to an upright position. Normally, you may want to maintain extensor muscle activity by stopping the upward lift about an inch or two from a full back extension, because when your back is fully erect, the weight is transferred through the vertebrae. This reduces the muscle activity. Continuing the upward lift until your back is hyperextended (i.e., leaning backwards) is potentially damaging to the intervertebral discs.
9. Finish the set at the top of the lift, and then take one step forward to return the barbell to the rack. Bend both trunk and knees, but keep your head and neck up to maintain a tight back as you lower the barbell on the power rack at the end of the set.
Important Tips
The three muscles of the erector spinae and the hamstring muscles all strongly contract during the lift upward (extending the vertebral column). These same muscles will undergo an eccentric (lengthening) contraction as they control the descent of the bar back toward the floor. This phase of the contraction is important for maximizing strength and mass development of the back extensors. The hamstring muscles are most active in the lower 1/3 of the movement and the gluteus maximus also assists the lower extension phases of the exercise. This is also the range that provides the greatest stretch on these muscles, so be careful to control the weight and do not pull the bar up explosively. The spinalis muscles contract isometrically throughout the exercise and this helps keep the vertebrae from rotating during the lift. The trapezius and other superficial upper back muscles and muscles of upper extremity (e.g., forearm) are active, but they act isometrically since they do not change muscle fiber length during the exercise.
Wrist straps provide a good tool for avoiding grip strength failure during your sets. This is certainly preferable to using an alternate handgrip in which one hand is pronated on the bar and the other supinated. An alternate grip rotates the spine toward the pronated hand as the weight is lifted. While a small amount of rotation of the spine with excessive weights will not hurt most backs- and this increases transversospinalis muscle activation- it certainly can aggravate and magnify any pre-existing injury. Furthermore, if, for example, the left hand is always supinated and the right hand is always pronated, the muscles on the pronated side will develop more strength and thickness at the expense of the muscles on the other half of the back. This creates an imbalance of strength that will predispose you to an intervertebral disc tear.
In general, thicker and stronger back extensors will stabilize and protect your back against injury. Thickening these large muscles may also have an anabolic effect that will extend to other muscle groups. In addition, these thick erector ropes running down your back will convey a sense of colossal strength, size and power that will accompany your every move, whether at the gym or on the beach. Nonetheless, because stronger erector spinae muscles are also capable of faster contractions and quicker twists using submaximal loads, the intervertebral discs may be more vulnerable to the wrong types of movement.
Thus, carefully approach and execute all back exercises, and any standing exercises, so that your newfound erector tower of strength will become one of your greatest training allies.
References
Brereton LC, McGill SM. Frequency response of spine extensors during rapid isometric contractions: effects of muscle length and tension. J Electromyogr Kinesiol 1998; 8: 227-232.
Callaghan JP, McGill SM. Muscle activity and low back loads under external shear and compressive loading. Spine 1995; 20: 992-998.
Cholewicki J and McGill SM. Lumbar posterior ligament involvement during extremely heavy lifts estimated from fluoroscopic measurements. J Biomech 25: 17-28, 1992.
Cholewicki J, McGill SM and Norman RW. Lumbar spine loads during the lifting of extremely heavy weights. Med Sci Sports Exerc 23: 1179-1186, 1991.
Escamilla RF, Francisco AC, Fleisig GS, Barrentine SW, Welch CM, Kayes AV, Speer KP and Andrews JR. A three-dimensional biomechanical analysis of sumo and conventional style deadlifts. Med Sci Sports Exerc 32: 1265-1275, 2000.
Escamilla RF, Francisco AC, Kayes AV, Speer KP and Moorman CT, III. An electromyographic analysis of sumo and conventional style deadlifts. Med Sci Sports Exerc 34: 682-688, 2002.
McGill SM. Low back exercises: evidence for improving exercise regimens. Phys Ther 1998; 78: 754-765.
Radebold A, Cholewicki J, Panjabi MM, Patel TC. Muscle response pattern to sudden trunk loading in healthy individuals and in patients with chronic low back pain. Spine 2000; 25: 947-954.
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