Why the Deadlift is for You: A Mechanical Analysis by Zach Chokr

[Zachary Chokr is a senior at North Carolina State University majoring in Psychology, minoring in Sports Science, and a Certified Personal Trainer under the National Academy of Sports Medicine. He is currently an Athletic Development Intern at Athletic Lab.]

The deadlift is one of the truest measures of total body strength as it recruits muscles from all regions of the body from the ground up. On the surface, the goal of the deadlift is essentially to pick up some weight off the ground to an erect, standing position. “While bending over and hoisting a weight off the floor may seem simple, form and technique can be different for each individual” (DuVall, 2017). However, the complexity of this lift can be easily overlooked. Some of the most important factors of the deadlift, and any exercise for that matter, is not just strength but form and technique. In my last blog post, I talked about the high bar and low bar squat. Now I am going to introduce two basic forms of the deadlift, and how you can benefit the most dependent on a variety of factors including your goals.

The conventional deadlift is performed with your feet roughly shoulder width apart, with your hands outside of them; whereas the sumo deadlift typically requires a wider stance, and hands placed on the bar between the feet. This difference in positioning places varying demands on the muscles. Escamilla et al. (2000) found that the primary lower extremity muscles involved during the conventional deadlifts are the hamstrings, gluteus maximus, gastrocnemius, and soleus, compared to the gluteus maximus, hamstrings, quadriceps, and tibialis anterior during the sumo deadlift using electromyography (EMG). The conventional deadlift requires greater spinal flexion, about 5-10%; whereas the sumo deadlift requires significantly more knee flexion (Cann, 2017). Greater knee flexion decreases the length moment arm at the hip resulting in a more upright torso and the hips closer to the bar in the sumo position; thus, decreasing the load placed on the spine and increasing the force required from the quadriceps. In the conventional deadlift, the hips are slightly higher and the moment arm is larger requiring greater spinal flexion. Thus, greater demands from the back (erector spinae) and hamstrings. Escamilla et al. (2000), Nuckols (2016), and Cann (2017) all found no significant difference in the demands of hip extension between sumo and conventional styles despite having different starting positions. Range of motion (ROM) should be mentioned, when comparing the two styles it is obvious that the sumo deadlift has a shorter ROM than a conventional deadlift, about 20-25% (Nuckols, 2016), but that does not mean sumo deadlifts are easier by any means. Cann (2017) and Nuckols (2016) can agree that you miss a lift because you were too weak through your weakest part of the movement, not because the bar has a greater distance to travel. One thing that makes the deadlift such a complex lift is the amount of muscles used throughout the lift. A weak point, where you might miss a lift, is just a point in the ROM where one or more of the muscles being used are not proportionally strong enough to continue the lift through the entire ROM. In the sumo deadlift, a weak point in the quads may result in trouble getting the bar off the floor; whereas the weak point in the conventional deadlift may be in the erectors off the floor. As the lift progresses in both sumo and conventional style, the hamstrings and gluteus muscles are responsible for hip extension.

There are also some physiological adaptations to consider when choosing which form is better for you in terms of maximal strength. Length of the arms and torso relative to the entire body can influence whether you might be better or more comfortable in either the sumo or conventional position. I’m not saying go out and measure the length of your arms and torso, but you can probably look in the mirror and tell if you have long arms or a short torso. “The conventional deadlift generates primarily large hip extensor moments, whereas the sumo style deadlift generates both knee and hip extensor moments” (Hales, 2010), therefore the force needed to proceed through each ROM is proportional to the length of the moment arms created at the joints responsible to extend. The greater the moment arm, the more force needed to extend at the moment, or joint. If you are just training deadlifts at a submaximal effort different than the goals of a sport such as powerlifting, it doesn’t really matter how much weight you’re lifting or which technique you use. However, if you are a powerlifter or training for maximal effort this may be something to consider. In the conventional deadlift, long arms paired with a short torso appears to be most advantageous by creating leverage allowing the lifter to lower their body to the bar while keeping their hips and back in an optimal position to decrease the moment arm at the hips responsible for extension. As arm length decreases and torso length increases, it appears to be more advantageous to deadlift sumo. In the sumo deadlift remember, the torso is more upright and the knees are more bent which creates the moment arms at the hips and knees. So a longer torso and shorter arms will decrease the moment arms at the knees and hips creating more leverage and requiring less force through the ROM. In submaximal effort training the force required move a load through its ROM is not as significant as in maximal effort loads. The table below summarizes the ratios of arm to torso length with the preferred deadlift style.

Table 1 (credit: elitefts.com)

Now that we’ve covered the technical and mechanical aspects of the deadlift, how can you benefit from this?

When executed properly the deadlift can improve absolute strength, speed strength, rate of force development, flexibility, and core stability while improving soft tissue and bone strength, as well as reduce the likelihood of various injuries during sport and other daily activities (Syatt, 2015). These advantages can lead to increased overall athletic performance and development. The benefits of the deadlift can be seen in “almost all fundamental sport skills such as running, jumping, throwing, and tackling” (Palmieri, 2012). In maximal effort athletes such as powerlifters, the variation can depend on your individual strengths, weaknesses, and body proportions. The conventional deadlift has greater motor recruitment of the posterior chain (hamstrings, gluteus maximus, and erector spinae); where the sumo deadlift disperses this demand into the quadriceps and off of the back, namely the erector spinae. Knowing which position fits your body can reduce discomfort and increase how much weight you can lift. The deadlift also serves rehabilitation purposes in strength athletes, such as football players, to enhance hip, thigh, and back strength. It can also contribute to ACL rehabilitation by activating the hamstrings to protect the knee (Escamilla, 2000).

Regardless of your goals, body type, and technique used, the Deadlift can provide a number of strength and health benefits to better you not only in the gym, but in your daily life.

Take home points of the deadlift:

  • Form is key and varies from individual
  • Greater force production
  • Increased athletic performance
  • Increased absolute and speed strength
  • Increased core strength and stability
  • Reduced likelihood of injuries
  • Improved bone strength
  • Anatomical differences can influence the preferred technique when training with maximal loads

Conventional:

  • Utilizes entire posterior chain
  • Greater resistance on lower back
  • Larger ROM
  • Long arms and a short torso can be more advantageous when working with maximal effort loads

Sumo:

  • Greater stress on quadriceps
  • Less resistance on lower back
  • Shorter ROM
  • Short arms and a long torso can be more advantageous when working with maximal effort loads

References

Cann, K. (2017, January 13). A Biomechanical Analysis of the Deadlift: Conventional vs Sumo. Retrieved March 27, 2017, from http://robbwolf.com/2017/01/18/a-biomechanical-analysis-of-the-deadlift-conventional-vs-sumo/

DuVall, J. (2017). Exercise Face-Off: Traditional Deadlift vs. Sumo Deadlift. Retrieved March 27, 2017, from http://www.mensfitness.com/training/build-muscle/exercise-face-off-traditional-deadlift-vs-sumo-deadlift

Escamilla, R. F., Francisco, A. C., Fleisig, G. S., Barrentine, S. W., Welch, C. M., Kayes, A. V., … & Andrews, J. R. (2000). A three-dimensional biomechanical analysis of sumo and conventional style deadlifts. Medicine and science in sports and exercise, 32(7), 1265-1275.

Hales M (2010) Improving the Deadlift: Understanding Biomechanical Constraints and Physiological Adaptations to Resistance Exercise. Strength and Conditioning Journal 32(4):44–51.

Nuckols, G. (2016, August 30). Should you Deadlift Conventional or Sumo? • Stronger by Science. Retrieved March 27, 2017, from http://www.strongerbyscience.com/should-you-deadlift-conventional-or-sumo/

Palmieri, M. (2012, October 19). Become a Better Athlete With the Deadlift. Retrieved March 28, 2017, from http://www.stack.com/a/deadlift-variations

Syatt, J. (2015, March 17). Sumo & Conventional Deadlifting: An Overview of Technique, Programming, and Individual Weaknesses. Retrieved March 28, 2017, from http://www.syattfitness.com/westside-barbell/sumo-conventional-deadlifting-an-overview-of-technique-programming-and-individual-weaknesses/

By | 2017-04-12T19:26:38+00:00 April 4th, 2017|Training Info|0 Comments

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