Muscular Strength Flashcards
What is power
Work/unit time or force x velocity
Involves strength and speed
What is muscular strength?
Greatest amount of force that muscles can produce in single maximal effort
What is dynamic (isotonic) contraction?
Bony levers move thru range of motion when appropriate muscles perform work
Concentric contraction
Muscle shortens w/varying tension as it lifts a constant load
Eccentric contraction
External resistance exceeds muscle force & muscle lengthens while developing force. Eccentric contractions usually used in resisting gravity
Isometric contraction
Static contraction. Tension developed but no change in angle of joint or length of muscle.
Isokinetic contraction
Muscle shorted at constant velocity determined by instrumentation which allows person to exert maximal force thruout full range of motion
One repetition maximum
Maximum amount of weight lifted once. Use free weights or machines that allow dynamic muscle contractions
Nautilus machines
accommodating resistance devices - leverage characteristics change as the joint goes thru range of motion so that muscle stressed more @ optimal joint angles
Dynamometer Techniques
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
Relatively inexpensive, high reliability if body position carefully standardized for each trial of test
What do dynamometer techniques measure & examples?
Isometric strength
hand grip dynamometer, Jackson strength evaluation system
Computer-assisted, isokinetic methods
computer which can be programmed @ any initial & final force, angle, velocity, or # of repititions25
