lifting
Last reviewed 01/2018
The diaphragm contracts during lifting to increase intrabdominal pressure. It may be assisted by closure of the glottis. Their combined action effectively produces 2 stiff, closed compartments - thorax and abdomen - which splint the spinal column. This facilitates muscles such as quadratus lumborum and erector spinae which are now liberated from roles as isometric struts to one of fuller extension of spine.