c. A Broad Base of Support and a Low Center of Gravity Desirable. Stable
objects have a broad base of support and a low center of gravity. The recumbent figure
and the box of chemicals in figure 1-9 are very stable because they have a broad base
of support and a low center of gravity. The body is most stable when the center of
gravity is nearest the center of the base of support. By carrying a load close to your
body rather than away from your body, the load will be close to your center of gravity.
You will expend less energy, feel less strain, and be less likely to suffer injury.
Figure 1-9. Factors promoting stability: a broad base of support, a low center of
gravity, a line of gravity that intersects the base of support.
d. Keeping the Center of Gravity Over the Base of Support. Note that in
figure 1-10, the line of gravity does not pass through the base of support. However, in
figure 1-11, the line of gravity passes through the base of support. This is a desirable
configuration that should be applied when lifting objects. When lifting an object, bend at
the knees and hips and keep your back straight (figure 1-11). Positioned in this
manner, the center of gravity will remain over the base of support (the feet) as it ought
to be, making it easier to keep your balance.
1-7.
RULES FOR LIFTING AND CARRYING HEAVY OBJECTS
a. The tips for good body mechanics and six common-sense rules for lifting and
carrying heavy objects, outlined below, recap the highlights of goad body mechanics.
By applying these principles, you will minimize strain on the weakest pan of your
muscular system, the muscles of the back. You rely, instead, more heavily on the
stronger muscles of the thighs, arms, and abdomen.
TIPS FOR GOOD BODY MECHANICS
Center of gravity is low.
Base of support is wide.
Line of gravity passes through base of support.
Body parts are in good alignment.
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