Biomechanical analysis of the deadlift during the 1999 Special Olympics World Games

Purpose: Improper lifting techniques may increase injury risks and decrease performance. The aim of this study was to compare and contrast biomechanic al parameters between sumo and conventional style deadlifts and between hig h- and low-skilled lifters who participated in the powerlifting event durin g the 1999 Special Olympics World Games, Methods: Two synchronized video ca meras collected 60 Hz of data from 40 subjects. Parameters were quantified at barbell liftoff (LO), when the barbell passed the knees (KP). and at lif t completion. Results: Compared with the conventional group, the sumo group had a 100%, greater stance width, 20%, smaller hand width. 10% less vertic al bar distance, a more vertical trunk at LO, a more horizontal thigh at LO and KP, a less vertical shank at KP. and greater forefoot abduction. The s umo group generated ankle dorsiflexor, knee extensor, and hip extensor mome nts, whereas the conventional group produced ankle plantar flexor. knee fle xor and extensor. and hip extensor moments. Compared with low-skilled lifte rs. high-skilled lifters had a 40% greater barbell load, 15% greater stance width (sumo group only), greater knee flexion at LO (conventional group on ly). greater knee extension at KP. a less vertical shank position at LO (su mo group only), 15% less vertical bar distance. less first peak bar velocit y between LO and KP (conventional group only), smaller plantar flexor and h ip extensor moment arms at LO and KP, and greater knee extensor moment arms at LO. Conclusions: The sumo deadlift may be more effective in working ank le dorsiflexors and knee extensors, whereas the conventional deadlift may b e more effective in working ankle plantar flexors and knee flexors. High-sk illed lifters exhibited better lifting mechanics than low-skilled lifters b y keeping the bar closer to the body, which may both enhance performance an d minimize injury risk.