A biomechanical analysis of straight and hexagonal barbell deadlifts using submaximal loads.

Swinton, Paul A.; Stewart, Arthur; Agouris, Ioannis; Keogh, Justin W.L.; Lloyd, Ray

Abstract

The purpose of the investigation was to compare the kinematics and kinetics of the deadlift performed with 2 distinct barbells across a range of submaximal loads. Nineteen male powerlifters performed the deadlift with a conventional straight barbell and a hexagonal barbell that allowed the lifter to stand within its frame. Subjects performed trials at maximum speed with loads of 10, 20, 30, 40, 50, 60, 70, and 80% of their predetermined 1- repetition maximum (1RM). Inverse dynamics and spatial tracking of the external resistance were used to quantify kinematic and kinetic variables. Subjects were able to lift a heavier 1RM load in the hexagonal barbell deadlift (HBD) than the straight barbell deadlift (SBD) (265±41 kg vs. 245±39 kg, p < 0.05). The design of the hexagonal barbell significantly altered the resistance moment at the joints analyzed (p < 0.05), resulting in lower peak moments at the lumbar spine, hip, and ankle (p < 0.05) and an increased peak moment at the knee (p < 0.05). Maximum peak power values of 4,388±713 and 4,872±636 W were obtained for the SBD and HBD, respectively (p < 0.05). Across the submaximal loads, significantly greater peak force, peak velocity and peak power values were produced during the HBD compared to during the SBD (p ± 0.05). The results demonstrate that the choice of barbell used to perform the deadlift has a significant effect on a range of kinematic and kinetic variables. The enhanced mechanical stimulus obtained with the hexagonal barbell suggests that in general the HBD is a more effective exercise than the SBD.

Citation

SWINTON, P.A., STEWART, A., AGOURIS, I., KEOGH, J.W.L. and LLOYD, R. 2011. A biomechanical analysis of straight and hexagonal barbell deadlifts using submaximal loads. Journal of strength and conditioning research [online], 25(7), pages 2000-2009. Available from: https://doi.org/10.1519/JSC.0b013e3181e73f87

• Journal Article Type: Article
• Acceptance Date: Jul 31, 2011
• Online Publication Date: Jul 31, 2011
• Publication Date: Jul 31, 2011
• Deposit Date: Nov 28, 2013
• Publicly Available Date: Nov 28, 2013
• Journal: Journal of strength and conditioning research
• Print ISSN: 1064-8011
• Electronic ISSN: 1533-4287
• Publisher: Lippincott, Williams & Wilkins
• Peer Reviewed: Peer Reviewed
• Volume: 25
• Issue: 7
• Pages: 2000-2009
• DOI: https://doi.org/10.1519/JSC.0b013e3181e73f87
• Keywords: Resistance trainingPowerVelocityForceKineticsKinematics
• Public URL: http://hdl.handle.net/10059/906
• Contract Date: Nov 28, 2013