If deadlifts, hex bar deadlifts, and hip thrusts frequent your workout program, then we have some good news. A recently published study in the Journal of Strength and Conditioning explored the electromyographic (EMG) differences between the three movements in regards to the glute maximus, biceps femoris, and erector spinae.
For most athlete and coaches, this is great news. After all, usually at least one of the above three movements is included in one’s strength and conditioning programs, if not all of them, so knowing how much a muscle is activated during each is useful information.
The objective of the study was to compare EMG ratings for the gluteus maximus, biceps femoris, and erector spinae in the deadlift, hex bar deadlift, and barbell hip thrust during 1-RM weighted loads at maximal voluntary contraction and at the top/bottom of the lift.
Subjects & Procedures
Researchers enlisted 13 healthy males (volunteers) who all had previous strength training history of 4.5 +/- 1.9 years and had trained the three movements before.
Subjects came into the lab twice for familiarization of the movements before testing their 1-RMs. The first time they came in researchers standardized technique for the three movements, so subjects all had prior study-oriented technique familiarization before performing their 1-RMs.
The second session included a bike/treadmill warm-up, and then a specific progressive barbell warm-up for the three movements. In this session, a subject’s progressive warm-up was based off their self-reported 1-RM. Then following, in the experimental session after the previously mentioned second familiarization, researchers aimed to assess the subject’s true 1-RMs and EMG ratings. Subjects progressively loaded per the 1-RM found after the second familiarization session described above (which would suggest the loading was a bit more accurate).
Upon their analysis, researchers reported a few differences between EMG ratings and the three movements, along with some similarities.
In terms of differences with the gluteus maximus, researchers suggested that the hip thrust produced a 16% greater EMG rating compared to the hex bar deadlift (it was similar to the deadlift). This was most apparent towards the top of the movement where the hip thrust gluteus maximus EMG rating was 26% greater than the hex bar deadlift.
For the biceps femoris, the deadlift produced greater EMG ratings compared to both the hex bar deadlift and barbell hip thrust, producing a 28% greater EMG rating compared to the hex bar deadlift and 20% to the hip thrust. At the bottom of the movements, the deadlift and hex bar deadlift both had greater EMG ratings in relation to the hip thrust. Then, at the top of the movements, the deadlift and hip thrust both rated higher than the hex bar deadift.
The erector spinae showed a consistent rating through all three movements during maximal voluntary contraction and towards the bottom and top of the movements.
This study was great because it used a population that’s similar to strength athletes and explored muscle activation of movements commonly used in workout programs. For the gluteus maximus, the hip thrust was suggested to produce the greatest EMG at maximal voluntary contraction, while the deadlift produced the most activation for the biceps femoris. Thus, for glute activation, the hip thrust may be one’s best bet, while the deadlift did a better job activating a section of the hamstrings.
At the bottom of movements for the biceps femoris, both the deadlift and hex bar deadlift displayed higher ratings, then at the top, the deadlift and hip thrust rated higher than the hex bar deadlift. The gluteus maximus were most active at the top of the three movements for the hip thrust.
These findings make sense when you consider the various levels of time under tension towards the top and bottom of these lifts (increased load on the hamstrings at the bottom of deadlifts, vice versa for the glutes at the top of the hip thrust).
Feature image screenshot from @bretcontreras1 Instagram page.