Any further tensing of the abdominal muscle may lead to additional spinal compression.
“Since the spinal compression in lifting approach the margins of safety of the spine, these seemingly small differences are not irrelevant”
Biggemann et al., 1988
Bending and lifting is associated with low abdominal muscle activity, which contributes to further spinal compression
de Looze et al., 1999
In patients with CLBP lifting is associated with higher levels of trunk co-contraction and spinal loading
Marras et al., 2005; Cholewicki et al., 1997
Psychological stress during lifting resulted in a dramatic increase in spinal compression associated with increases in trunk muscle co-contraction and less controlled movements Davis et al., 2002