The Biomechanics of Strength 4: The Deadlift.

There are many variations of the deadlift, and in this article we are going to look at some of the similarities and differences between the two main variations of these lifts used to develop maximum strength. From a powerlifting performance, the two main types are the sumo and conventional deadlift. Both of these type of deadlifts requires coordinated activation of the muscles of both the lower and upper limb including the quadriceps, hamstrings, hip flexors and extensors and the spinal erectors, and the muscles of the upper back. However, there are subtle biomechanical and anatomical differences which will influence the technique that will best suit you.

The technique with which you will get the best results will largely be determined by your own structure, particularly that of how your femurs insert into the pelvis. This will influence structure of the muscles around the pelvis, determine the different leverages placed on these muscles and ultimately define where you are able to generate your greatest mechanical advantage and lift your heaviest loads. To determine which technique suits you best, the most important thing is to give them a try and see which works for you, or to get a trained eye to take a look at your technique, overall body structure and to help point you in the right direction.

In the sumo deadlift, the legs are wide apart with the toes often only a few cm from the weight plates. The hands grip the bar inside the knees, with a fairly narrow grip. This combination of a wide stance, effectively shortening the distance the legs have to move to lock out, and narrow grip, lengthening the arms so the amount of back extension required to complete the lift, means that the bar has to travel a relatively shorter distance than in a conventional deadlift (approximately a 20-25% shorter range of motion). In the conventional deadlift, the feet are approximately shoulder width apart and the hands are outside of the knees.

It may seem that the sumo deadlift has a big advantage over conventional deadlifts, but this is not necessarily the case; neither from a deeper mechanical perspective nor anecdotally when we look at the biggest dead lifters in history! This is partly because there is a trade-off between positioning the body to shorten the distance the bar has to travel and the impact this has on the ability to recruit muscles to generate maximum strength. The trade off with shortening the distance a bar has to travel with the ability to activate muscles and generate maximum force is also evident in the bench press when we consider wide versus narrow grip pressing, but we’ll get onto that in the next part of our biomechanics for strength article.

In the sumo deadlift, we place ourselves in a starting position where the back is in a more upright position, and the hamstrings and glutes are in a stretched and active position. This means that getting the bar off the floor can be easier as the muscles are already in a primed position to do this. However, this comes with a trade-off; as the bar lifts the lock out of the deadlift it becomes challenging as the hands may be dragged up the thigh, creating unwanted friction. Additionally, the sumo deadlift creates a much greater demand on the quadriceps than conventional deadlift. The hip extensors are very important in locking out the lift in both sumo and conventional deadlifts and muscle activation patterns between the two lifts are similar. The more upright the start position of the sumo deadlift means that there is less recruitment and demand placed on the erectors than the conventional style. This means that the area in which you are strongest (quads or back) is going to play a big role in which technique you employ.

One of the most challenging things that conventional deadlifter’s have to face is to get into the right start position and maintain a strong spinal position throughout the lift. A key way to do this is by keeping your body as far behind the bar as possible to counterbalance the load being lifted, stop the bar drifting forwards and reduces unnecessary demands on the erectors to keep their focus on lifting the load and protecting the spine by keeping it in a favourable position. Once the bar pulls you forward, this is going to make the lift exponentially difficult and increase risk of injury. Deadlifting with proper technique, the bar should be kept close over the mid foot with the bar being pulled as close to the body as possible to reduce any moment arms of the bar acting on the ankle, knee and hip and keep the bar path as straight as possible. Although we have further to travel with the conventional deadlift and the starting position can be more difficult to maintain a straight back and keep the bar over our base of support, the conventional deadlift allows us to recruit the muscles of the lower back and glutes in to the lift more effectively if we get the technique nailed correctly.

We are going to finish this article with the most important consideration when deadlifting and that is how to protect the lower back. Whatever deadlift technique you employ, one important rule is to ensure the spine maintains as neutral a position as possible; rounding of the upper back is generally not an issue, but if flexion occurs excessively in the lumbar region, this can be a recipe for disaster. It is important, even at lighter loads when developing technique, to work on activating the muscles of the upper and lower back. It is important to be able to effectively engage the trapezius muscles and the rear deltoids that stabilise the shoulder joint and upper back alongside your ‘lats’ which are also going to also assist the erectors in stabilising the spine and reduce risk of injury, and also to improve your strength.

If you continually fail deadlifts at a specific point in the lift, then this is likely to be caused by a weakness in your kinetic chain or deficiency in technique which are not always easy to identify. As always, if you’d like our help or want to know a little more about how we can help you with your technique, identifying your weaknesses and how to overcome them, then please don’t hesitate to get in touch.

Team TTC.