Unformatted text preview: MUSCULAR STRENGTH Muscular strength - the greatest amount of force that muscles can produce in
a single maximal effort. Power - work per unit time - force X velocity.
Power involves strength and speed. A. Types of Muscular Contraction 1. Dynamic (isotonic) contraction - the bony levers move through a range of
motion when the appropriate muscles perform work. Concentric contraction - the muscle shortens with varying tension as it
lifts a constant load. Eccentric contraction - the external resistance exceeds the muscle force
and the muscle lengthens while developing force. Eccentric contractions
are usually used in resisting gravity. 2. Isometric contraction - static contraction. Tension is developed but there
is no change in the angle of the joint or the length of the muscle. 3. Isokinetic contraction - the muscle is shortened at a constant velocity
determined by instrumentation which allows a person to exert maximal
force throughout the full range of motion. B. Strength Testing Technigues 1. One Repetition Maximum - maximum amount of weight lifted once.
Use free weights or machines that allow dynamic muscle contractions -
Universal Gym, etc. Nautilus Machines - accomodating resistance devices - leverage
characteristics change as the joint goes through a range of motion so that
the muscle is stressed more at more optimal joint angles. 2. Dynamometer Techniques - a strength testing dynamometer usually
consists of a spring of some type which is deformed a certain amount
when a specific force is applied to it. (eg) - hand grip dynamometer ...
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- Spring '09