A kinetic and kinematic comparison of the traditional and sumo deadlifts

Abstract

Low-back pain and chronic back injury have been a common occurrence in weightlifting. The risk of injury to the low-back is increased in the deadlift due to the heavy loads that are lifted. While it is generally accepted that the traditional style deadlift creates a greater force on the 1umbo-sacral articulation than the sumo style, the actual forces incurred during the deadlift have not been determined. The purpose of this investigation was to compare the traditional and sumo style deadlifts with respect to lumbo-sacral forces and angular positions and velocities of the relative trunk and knee. Subjects were competitive traditional (n=4) or sumo (n=4) style deadlifters. The subjects were videotaped with an Olympus VHS movie video camera operating at a speed of 30 frames per second while performing three lifts at each of three weights (40, 60, & 80% of maximum) with a five minute rest between each lift. Coordinate data for the start, mid-point, and end of each lift were collected using a Targa 16 image capture board. Joint centers for a the ankle, knee, hip, shoulder, and the bar were digitized. The resultant muscle force, compression force, and shear force at the lumbo-sacral articulation were determined. In addition, the angular positions and velocities of the relative trunk and knee were obtained. For each variable, the average of the three trials per weight was used in the analysis. The traditional and sumo deadlifts were found to differ with respect to the resultant muscle force, compression force, and angular position of the relative trunk. No differences were found between the two lifting styles for shear force, angular position of the knee, or angular velocities of the relative trunk or knee. Evidence was found to suggest that traditional style deadlifters may be more prone to muscle strain and compression injuries at the L5/S1 articulation than are sumo style deadlifters. Evidence was also found to suggest that large incremental increases in the weight of the load may increase the risk of muscle, compression, and shear injuries to the lumbo-sacral articulation.