Differences in muscle activation and joint kinematics between deadlift styles when performed at high intensity training loads

Abstract

The purpose of this study was to compare the conventional (CDL), sumo (SDL) and hex-bar (HBD) deadlift actions at a high intensity training load across a wide range of leg and back muscles to explore which lift has the biggest impact on prime mover musculature. Twelve males (age: 19 ± 2 years; height: 1.81 ± 0.81 m; body mass: 85.64 ± 10.87 kg) performed 3 repetitions of HBD, CDL and SDL at a 90% 1RM intensity. Load lifted, EMG for the Erector Spinae Longissimus, Gluteus Maximus, Biceps Femoris, Semitendinosus, Rectus Femoris, and Vastus Medialis and knee and hip range were compared via effect size magnitude of change. The EMG results showed a general pattern of greater muscle activity, considered a large effect, during the HBD compared to the CDL and SDL, possibly due to the greater absolute load lifted during the HBD. The only anomaly to this was greater EMG activity for the bicep femoris within the CDL compared to the HBD, large effect, and the SDL, moderate effect. This finding was attributed to the greater hip flexion seen in the start position for the CDL compared to other lifts. These findings suggest that the HBD would be the preferred deadlift technique for total muscle recruitment and load lifted for high intensity (90% 1RM) training regimes. However, the CDL would be the preferred lift if bicep femoris muscle activity were a specific targeted requirement.