ESCAMILLA, R. F., A. C. FRANCISCO, A. V. KAYES, K. P. SPEER, and C. T. MOORMAN, III. An electromyographic analysis of sumo and conventional style deadlifts. Med. Sci. Sports Exerc., Vol. 34, No. 4, pp. 682–688, 2002.
Purpose: Strength athletes often employ the deadlift in their training or rehabilitation regimens. The purpose of this study was to compare muscle activity between sumo and conventional style deadlifts, and between belt and no-belt conditions.
Methods: Six cameras collected 60-Hz video data and 960-Hz electromyographic data from 13 collegiate football players who performed sumo and conventional deadlifts with and without a lifting belt, employing a 12-RM intensity. Variables measured were knee angles and EMG measurements from 16 muscles. Muscle activity were averaged and compared within three 30° knee angle intervals from 90 to 0° during the ascent, and three 30° knee angle intervals from 0 to 90° during the descent.
Results: Overall EMG activity from the vastus medialis, vastus lateralis, and tibialis anterior were significantly greater in the sumo deadlift, whereas overall EMG activity from the medial gastrocnemius was significantly greater in the conventional deadlift. Compared with the no-belt condition, the belt condition produced significantly greater rectus abdominis activity and significantly less external oblique activity. For most muscles, EMG activity was significantly greater in the knee extending intervals compared with the corresponding knee flexing intervals. Quadriceps, tibialis anterior, hip adductor, gluteus maximus, L3 and T12 paraspinal, and middle trapezius activity were significantly greater in higher knee flexion intervals compared with lower knee flexion intervals, whereas hamstrings, gastrocnemius, and upper trapezius activity were greater in lower knee flexion intervals compared with higher knee flexion intervals.
Conclusions: Athletes may choose to employ either the sumo or conventional deadlift style, depending on which muscles are considered most important according to their training protocols. Moderate to high co-contractions from the quadriceps, hamstrings, and gastrocnemius imply that the deadlift may be an effective closed kinetic chain exercise for strength athletes to employ during knee rehabilitation.