The load acting on the lower spine
Ekholm et al. [7] studied the effect of mass acting on
the lower spine while lifting heavy objects. The forces
and moments acting on the lower spine were separated
into 3 sources which are 1. the force from body weight
above the lower spine, 2. the force from objects weight
during transport and 3. the force resulting from
Extensor Erector Spinae contraction. The Erector
Spinae muscle serves to extend the back by contracting
a force parallel to the spine which has a distance
approximately 4 cm. from the center of L5/S1
Intervertebral disc