D3 - Spine mechanics for lifters Flashcards
1
Q
What is shear in the context of force?
A
Shear is defined as a force that acts parallel to a surface
2
Q
In a deadlift
A
why does it create a significant torque about the lumbar vertebrae?
3
Q
What additional force acts downward in a deadlift?
A
In addition to creating a torque
4
Q
What is the true shear on the L4-L5 joint in deadlifting?
A
The true shear on the L4-L5 joint is the resultant shear force produced by the sum of the reaction shear and the muscle/ligament shear. Maintaining the natural curve of the lumbar spine allows the spinal erector musculature to create the opposing torque during the lift.
5
Q
According to the text
A
when does shear on the back not occur?
6
Q
Why is it important to maintain a rigid
A
straight back during lifting?
