Mike Gittleson was the Director of Strength & Conditioning at the University of Michigan for 30 years and was a part of 15 Football Championships in that time. He explains, sudden and unexpected loading generates high forces on the lumbar spine with very little contribution of the abs.
In a recent study, scientists put electrodes on the abs and back muscles of volunteers to measure muscular activity during the handling of various objects and loads.
Sudden and alarming events caused a reflex overreaction of the back muscles, which substantially increased spine compressive loading. The contribution from abdominal muscle contraction to overall spinal compression was small, about 8%.
This makes sense since the muscles that are involved in the control of limb stiffness, and in this instance they are the muscles of thoracic and lumbar spine, quickly when displaced try to return to their original position.The stretch reflex is often described as a device for assisting in the regulation of muscle length or as a spinal servomechanism.
This phenomena of reflexively returning the displaced limb to its intended position requires that the abs relax enough in order to move the lumbar spine back, hence only a small percentage of abdominal involvement. Sudden and unexpected loading generates high forces on the lumbar spine.Something to think about as you are working to Get Strong.
Durniat's version of the Power Clean