A three dimensional kinematic comparison of the conventional versus sumo style deadlifts

The primary purpose of this study is to use three-dimensional motion analysis to determine and compare certain kinematic joint and segmental variables at defined events (bar off and knee passing) between the conventional and sumo styles of deadlifts. The secondary purpose of this study is to investigate bar path profiles and vertical bar velocity patterns (including attempting to determine a "sticking region") and compare these variables between the two styles and two sub-maximal loads (50% and 75%). Five subjects performed each style at each load. Each trial was filmed, digitized, and imported for 3-D reconstruction. This data was utilized to determine hip, knee, inter-thigh, trunk, thigh, and shank angles at bar off and knee passing; bar path profiles; and bar velocity values (including determining the "sticking region"). A two way ANOVA showed statistically significant differences between the two styles for most joint and segmental variables at both events and the range between the two events. There was a significant difference between the two styles for total time and horizontal and vertical bar displacement. Only one trial showed a sticking region. Based on the results of this study, it can be stated that kinematic differences do occur between the two styles of deadlifts at submaximal loads. A sticking region does not appear to occur at loads of 75% of a 1 rep maximum or less.School of Physical EducationThesis (M.S.