What do we need to look at?
- What the mechanical differences are between sumo and conventional
- What muscles are preferentially used?
- What individual characteristics need to be taken into account?
The differing angles in conventional and sumo mean that there are different stresses placed on the knee and hip extensors to lift the weight. Because on this, the loading demands for which muscles are used changes.
WHAT ARE THE MECHANICAL DIFFERENCES
- Due to the wider stance, the front to back femur length is shorter in sumo in comparison to conventional. This means that torso is able to start in a less inclined, more upright position and hips are closer to the bar – this also means that less demands are placed on the lower back and so lower back strength is less likely to be a limiting factor than it could be in conventional.
- The narrower stance in conventional means that the torso starts in a more bent over position. A further inclined torso angle means the hips are further back and there is a greater shear loading/demand on the spinal extensors
WHAT MUSCLES ARE PREFERENTIALLY USED?
- Sumo deadlifts demand more from your quads than conventional. In a study conducted by Escamilla et al., (2010) it was found that when the bar broke the ground, knee moment was approximately 3x higher for sumo deadlifts than conventional deadlifts. This was also reflected in another study they did, looking at EMG data. EMG readings for the quads (vastus lateralis and medialis) were higher in sumo deadlifts than conventional.
- Conventional deadlifts are harder on your spinal erectors off the floor. Data from Cholewicki et al., (1991) show that spinal extension demands are around 10% higher in conventional in comparison to sumo. Since the torso is leant further forward at the start of the lift in conventional, it makes sense that a harder contraction of the spinal erectors is needed keep the back extended as the bar breaks off the floor. Depending on hip placement in relation to the bar at the start of a conventional pull, it may have greater glute activation than sumo but researchers are still undecided.
SO WHAT DO YOU NEED TO CONSIDER?
LEVER LENGTH / ANATOMINCAL CONSIDERATIONS
Hales (2010) published an article that provided recommendations on the style of deadlift that could lead to greater potential for performance based on an athletes limb length proportions (table below) The logic behind this study suggested that it would enable a lifter to ‘select the style that accentuates their individualistic physical characteristics.’
To find out whether you are considered to have ‘long’ or ‘short’ limbs take a look at the table below adapted from Hales (2010). To find out your % measure your height and then body segment length (torso, arm, or leg). Divide your segment length by your height and multiply by 100.
i.e. If your height is 166cm and your arm length is 70cm your % is 42 and you are considered to have long arms. Do this again with your torso and legs to find out your proportions and suggested deadlift stance.
MUSCULAR STRUCTRE AND WEAKNESS CONSIDERATIONS
Another consideration when choosing between conventional or sumo is muscle strengths and weaknesses/distribution. A lifter may naturally gravitate towards the stance that demands more from muscles that are relatively strong compared to others that may be weaker.
With conventional there’s slightly more forward lean and so there’s greater muscular activation in the trunk muscles like the spinal erectors. For sumo there’s greater knee extension, which places more loading demand on the quads. Given this, you’ll want to play to your strengths. If you’ve spent years developing your lower and mid back and they’re considerably stronger than your quads, you may be best suited to pulling conventional as opposed to sumo.
On top of this, there are several other factors to consider when looking to see which stance is best: historic injuries; bodyweight; fatigue accumulation of certain body parts, e.g. lower back; bone and joint angles of the hip etc.
Hip structure is a huge determinant of whether you’re stronger in straight-ahead hip flexion (favouring conventional) or hip flexion with hip abduction (favouring sumo).
Whilst you can’t change what shape and size your pelvis is, it’s worth knowing that variables like:
hip socket location forward or farther back on the pelvis
hip socket depth
the angle of the femur where it meets the pelvis
how rotated the femur is where it meets the pelvis.
will determine the range of motion your hips can go through, and the amount of muscular tension you can develop in different hip positions.
PREVIOUS EXPERIENCE AND HISTORY OF INJURIES
The nature of conventional deadlifts and the increased demand they place on the lower back means that they may not be the most appropriate choice if we’re wanting to reduce the demand on the spinal erectors and lower back.
Conversely, conventional deadlifts are a valid choice for an athlete with a ‘weak link’ back if they’re looking to improve it and can perform it with minimal risk to injury. It goes without saying that this is individual athlete dependent and a blanket answer won’t do here.
Take away points:
- Your hip structure will impact your strength and comfort in conventional and sumo deadlifts more than factors like height and limb lengths.
- Conventional = easier on quads, harder on back – easier off the ground, harder at lockout
- Sumo = harder on quads, easier on back – harder off ground, easier at lockout.
- Although ROM is approximately 20% less in sumo (Escamilla et al., 2000), hip extension demands are very similar between conventional and sumo.
- Multiple factors determine which stance is ‘better’ for an athlete, primarily individualised characteristics as well as their goals.
Cholewicki, J., McGill, S.M. and Norman, R.W., 1991. Lumbar spine loads during the lifting of extremely heavy weights. Medicine and science in sports and exercise, 23(10), pp.1179-1186.
Escamilla, RF., Francisco, AC., Kayes, AV., Speer, KP., Moorman, CT. (2002) An electromyographic analysis of sumo and conventional style deadlifts. Medicine Science Sport Exercise, 34(4): 682-688.
Escamilla, R.F., Francisco, A.C., Fleisig, G.S., Barrentine, S.W., Welch, C.M., Kayes, A.V., Speer, K.P. and Andrews, J.R., 2000. A three-dimensional biomechanical analysis of sumo and conventional style deadlifts. Medicine and science in sports and exercise, 32(7), pp.1265-1275.
Hales M (2010) Improving the Deadlift: Understanding Biomechanical Constraints and Physiological Adaptations to Resistance Exercise. Strength and Conditioning Journal32(4):44–51.