oulders and the upper back
will be brought into play. If the arms are held close to the body, the
lower-arm muscles are unduly taxed and in trying to help them out,
pressure is made on the abdominal and pelvic muscles, which are not
fitted to bear this sort of strain. Therefore, in carrying a bag or
suitcase, where this is absolutely unavoidable, try to swing the arm
free from the body, so as to use the upper arm and back muscles for the
weight.

Another important way to save strain is by pushing instead of pulling.
It is almost impossible to push anything so hard as to injure your back
or abdominal muscles. It is almost impossible, on the other hand, to
pull even a relatively light weight without some strain. If you will
think of how a horse in harness actually exerts his strength in drawing
a wagon, you will see that what he does is to _push_ against the straps,
and it is the straps that _pull_ the wagon. Even the strongest horse
could not pull a wagon with his teeth very far, or pull something tied
only to the back leg muscles. _Get behind and push_ is the rule to
remember, and never resort to _pulling_ until you have tried every
device for pushing instead.

If you _must_ pull, try to use heavy muscles, such as _leg_ muscles, to
do it with. Often a weight may be lifted or pulled by getting the foot
under or in back and using the arms only to steer with. This applies
particularly to objects like trunks or bureaus.

Always take advantage of any natural leverage that you can and if you
must move something heavy, do not lift it at once and attempt to carry
it, but lift one end and swing or shove it and then lift the other end
and shove it. If you will watch expressmen at work you will notice that
they roll boxes and trunks, holding them almost on end and tipping them
just enough to turn them along their shortest axis. In this way the
boxes carry themselves, so far as their main weight is concerned.

Carrying a weight on the head or shoulders is another way of converting
a pull into a push, and this is taken advantage of by peasant women in
Europe, who often are seen carrying heavy weights to market in baskets
perched on their heads, while they stride along arm-free. A knapsack
strapped on to the shoulders is not only more convenient because it
leaves the arms and hands free to swing naturally or use for other
purposes, but because the weight is distributed and is carried by means
of heavy muscles pushing up under the