Learn why humans can
effectively sit up from supine position and other animals cannot.
After reviewing this
introduction section you can proceed to:
Physics
Labs section and there view Performing Sit Ups
By opening
course 2 preview and viewing
slides 24 through 41 you will see sit up as a biomechanical study of
human movement utilizing muscular skeletal leverage physics the
course would teach you to understand
We are going to use the
example of the heavy lift crane for purposes of explanation.
A crane is used to lift things.
Why a crane is strong.
 
How a crane does not lift.
A crane does not lift like this or it would collapse.
Why a crane collapses if it lifts wrong.
The human spine with the adult S-shape posture has build in
cranes in the neck and lower back.
This S-shaped structure allows us to lift up our heads or
sit up using strong crane-like movements.
Babies and animals have C-shaped spines that are weak for
these types of movements.
This type of crane set up lifts poorly.
If the infant or animal tries to sit up, the joints get
strained and want to collapse like the faulty crane structure above. This
is why you don't see them or people that don't have the proper curves sit up
well.
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