AN EXAMINATION OF MUSCLE ACTIVATION AND POWER CHARACTERISTICS WHILE PERFORMING THE DEADLIFT EXERCISE WITH STRAIGHT AND HEXAGONAL BARBELLS KEVIN D. CAMARA,JARED W. COBURN,DUSTIN D. DUNNICK,LEE E. BROWN,ANDREW J. GALPIN, AND PABLO B. COSTA Department of Kinesiology, Center for Sport Performance, California State University, Fullerton, California ABSTRACT Camara, KD, Coburn, JW, Dunnick, DD, Brown, LE, Galpin, AJ, and Costa, PB. An examination of muscle activation and power characteristics while performing the deadlift exercise with straight and hexagonal barbells. J Strength Cond Res 30(5): 1183–1188, 2016—The deadlift exercise is commonly per- formed to develop strength and power, and to train the lower-body and erector spinae muscle groups. However, little is known about the acute training effects of a hexagonal barbell vs. a straight barbell when performing deadlifts. Therefore, the purpose of this study was to examine the hexagonal barbell in comparison with the straight barbell by analyzing electromyog- raphy (EMG) from the vastus lateralis, biceps femoris, and erector spinae, as well as peak force, peak power, and peak velocity using a force plate. Twenty men with deadlifting expe- rience volunteered to participate in the study. All participants completed a 1 repetition maximum (1RM) test with each bar- bell on 2 separate occasions. Three repetitions at 65 and 85% 1RM were performed with each barbell on a third visit. The results revealed that there was no significant difference for 1RM values between the straight and hexagonal barbells (mean 6 SD in kg = 181.4 6 27.3 vs. 181.1 6 27.6, respec- tively) (p . 0.05). Significantly greater normalized EMG values were found from the vastus lateralis for both the concentric (1.199 6 0.22) and eccentric (0.879 6 0.31) phases of the hexagonal-barbell deadlift than those of the straight-barbell deadlift (0.968 6 0.22 and 0.559 6 1.26), whereas the straight-barbell deadlift led to significantly greater EMG values from the bicep femoris during the concentric phase (0.835 6 0.19) and the erector spinae (0.753 6 0.28) during the eccen- tric phase than the corresponding values for the hexagonal- barbell deadlift (0.723 6 0.20 and 0.614 6 0.21) (p # 0.05). In addition, the hexagonal-barbell deadlift demonstrated significantly greater peak force (2,553.20 6 371.52 N), peak power (1,871.15 6 451.61 W), and peak velocity (0.805 6 0.165) values than those of the straight-barbell deadlift (2,509.90 6 364.95 N, 1,639.70 6 361.94 W, and 0.725 6 0.138 m$s 21 , respectively) (p # 0.05). These results sug- gest that the barbells led to different patterns of muscle acti- vation and that the hexagonal barbell may be more effective at developing maximal force, power, and velocity. KEY WORDS electromyography, vastus lateralis, biceps femoris, erector spinae, peak power, peak force, peak velocity INTRODUCTION T he deadlift exercise is widely used by athletes of many sports, as well as recreational lifters, to enhance power and strength (20). The exercise is a multijoint movement that activates several large muscle groups. Research has shown that, compared to other free weight exercises, the deadlift involves the lifting of heavier loads (1,10). The ability to lift heavier loads elicits a larger stimulus to adapt, making it ideal for enhancing muscular strength, which contributes to power (20). The movement requires grasping a barbell while in a squatting position and then elevating the barbell by extending the hips, knees, and ankles. When the hips are fully extended the concentric portion of the movement has ended. The barbell traveling downward until it reaches the floor or starting position completes the eccentric portion of the deadlift. The movement begins with the barbell starting at the midleg level and should remain close to the leg, thighs, and hips as the barbell elevates (1). It is vital that the barbell remain close to the lower extremities throughout the lift to reduce the moment arm of the barbell at the individual joints, decreas- ing the resistance of the external load (7). In comparison with other strength exercises, such as the squat, the deadlift has received comparatively little research interest (2,4,5,9,11,13,19). A common belief is that the dead- lift and back squat have similar movement patterns and that it is acceptable to relate theories and new findings between the 2 exercises. However, this was shown to be false through Address correspondence to Jared W. Coburn, jcoburn@fullerton.edu. 30(5)/1183–1188 Journal of Strength and Conditioning Research Ó 2016 National Strength and Conditioning Association VOLUME 30 | NUMBER 5 | MAY 2016 | 1183 Copyright © National Strength and Conditioning Association Unauthorized reproduction of this article is prohibited.