T Nation

New research. Belt or Beltless.

"Med Sci Sports Exerc 2002 Apr; 34(4): 682-8

An electromyographic analysis of sumo and conventional style deadlifts

Escamilla RF, Francisco AC, Kayes AV, Speer KP, Moorman CT 3rd

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-degree knee angle
intervals from 90 to 0 degrees during the ascent, and three 30-degree knee
angle intervals from 0 to 90 degrees 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."

I’m going to take a stab at this one… The rectus abdominis probably recorded greater ‘activity’ because they were forced to push out against the belt. Also, it does not mention the deep abdominal muscles, such as the stabilising transversus (sp?) abdomonis which would’ve shown less activity than the beltless lift.