Electromyographic comparison of the barbell deadlift using constant versus variable resistance in healthy, trained men

Abstract

Variable, external resistance is proposed to increasingly augment the muscular stress throughout a dynamic movement. However, it is uncertain how different levels of variable resistance affect the activation in the deadlift. The aim of the study was to compare the electromyographic activity of the gluteus maximus, biceps femoris, semitendinosus, vastus lateralis and erector spinae muscles during the barbell deadlift with free weights (FW) alone, with two (FW-2EB), and four elastic bands (FW-4EB) to deload some of the constant external resistance. Fifteen resistance-trained men participated in a cross-over design where resistance loadings were matched using two-repetition maximum loadings in the three different conditions. For the whole movement, both repetitions were analyzed. For the phase-specific analysis, the last repetition was divided into six parts, i.e. the lower, middle and upper phase in both the ascending and descending phase of the movement. The mean deloading contributions from FW-2EB and FW-4EB were 21% and 41%, respectively. In FW-4EB, the erector spinae was activated more in the whole movement (8%, ES = 0.31, p = 0.002) compared to FW-2EB. There was also a tendency towards higher activation in FW-4EB versus FW for the whole movement (5%, ES = 0.18, p = 0.072). There were no significant differences between the conditions in any of the other phases or muscles (p = 0.106–0.926). In summary, a high contribution from variable, external resistance seems to activate the back extensors more than a low contribution.

Core Muscle Activity during Physical Fitness Exercises: A Systematic Review

“…In relation to free-weight exercises, the greatest activation was found on the deadlift (barbell deadlift:~90% MVIC; hex bar deadlift:~80% MVIC) and hip-thrust exercise (~85% MVIC) [46]. Also, the back squat performed until failure and 2RM deadlift reported the highest mV values (~0.35 mV) [28,40].…”

“…The participant, in a standing position with feet shoulder-width apart, has to lower the body in order to lift the barbell until the hip is fully extended while maintaining a neutral spine position. This exercise may vary depending on specific protocols (e.g., Romanian deadlift, stiff leg, hexagonal bar deadlift) [40,44,46].…”

Acute Effects of Elastic Bands as Resistance or Assistance on EMG, Kinetics, and Kinematics During Deadlift in Resistance-Trained Men

“…In contrast to Galpin et al they found the variable resistance to increase the force, but reduce the velocity when compared to free weights. Finally, only one study has compared free weight deadlift with assisted deadlift (Andersen et al, 2019 ). Andersen et al ( 2019 ) compared muscle activation in the hamstring, gluteus, and erector spinae muscles between 2 RM in free weights vs. free weights in combination with either a high or a low contribution from elastic bands among resistance-trained men.…”

“…Finally, only one study has compared free weight deadlift with assisted deadlift (Andersen et al, 2019 ). Andersen et al ( 2019 ) compared muscle activation in the hamstring, gluteus, and erector spinae muscles between 2 RM in free weights vs. free weights in combination with either a high or a low contribution from elastic bands among resistance-trained men. The results showed a higher activation in the erector spinae, favoring the high assistance condition when compared to the low assisted condition, but with no difference to the free weights.…”

“…Therefore, the aim of the study was to compare neuromuscular activation, kinetics and kinematics between free weight-, resisted- and assisted deadlift using a matched relative intensity (one rep using 2-RM loading). Based on the previous study using relative intensity (Andersen et al, 2019 ) we hypothesized that the lower back would demonstrate higher activation during the elastic band-conditions compared to the free weights. Further, we hypothesized both band conditions to produce more force than the free weights, but the assisted band-conditions to be favorable among the two.…”