Exam 2 Flashcards
3 types of strength
Isometric
Isotonic
Isokinetic
Isometric
same length
Isotonic
same tension
Isokinetic
same speed
Isometric contraction
No visible movement
Muscle tension varies with number of motor units involved
The least gain for most time involved
Isometric contraction is useful for:
rehabilitation
sticking points
Sticking points
Targets the weakest part of a movement
1 RM=
the most weight lifted one time
always an isotonic measure
load does not change
Toning
partial state of muscle contraction
Isotonic stimulus
free weights
pulley machines
field tests
Isotonic exercise
when contracting muscles shorten against a constant load (shifting a weight)
Isokinetic exercise
movements that take place at a controlled rate of speed
constant speed with changing force
Isokinetics use
cams
Isotonic uses
pulleys
Cam
an odd shaped heel
radius is different
pivot distances change
Pulleys
r is equal
changes direction of the pull
If the cam increases/decreases…
the distance (d2) then work2 must change
When work2 is altered,
work1 must also change
F1 is the force applied by person lifting…
it is increased/decreased by the change in worl
Strength
short burst of high intensity followed by long rest pause
Muscle endurance
repetitive bouts of lower intensity with little or no rest pauses
Motor unit
one nerve, many muscle cells
Firing order…
creates a range of applied force
Hypertrophy results from
multiple myofibrils enlarging OR
increased fluid OR
Both
Both males and females can
hypertrophy
Must remove fat to…
show musculature
To measure strength…
1 RM (work= force x distance)
To measure power…
Time the 1 RM lift (work/time)
Muscle endurance
choose a weight, lift to failure
Muscular force…
changes with joint angle
1 RM isotonically
weakest point on a strength curve
Best isotonic weight training machine
shoulder extension strength curve
see graph
Best isokinetic weight training machine
Hip flexion strength curve
see graph
Relative Perceived Exertion (RPE)
Gunnar Borg Scale
older to newer
Electromyograph
detects electrical potential from skeletal muscle cells
Eccentric 1 RM differs from…
concentric 1 RM
How to increase a sprint:
Biomechanical analysis correct inefficiencies
Lift weight at each joint (one part of a time)
mirror speed of movement at each joint with resistance
Fiber=
Cell
Type 1=
slow twitch
Type II=
Fast twitch
Type IIa example
walking muscles
Motor unit are all…
fast twitch or slow twitch
Can’t change…
between slow to fast twitch and vice versa
Fast twitch: Type IIB
Power, quick fatigue
Football, shotput, sprinting/hurdles, high jump
Fast Twitch A: Type IIA
Moderate force, moderate fatigue
lose force, gain tension
gymnastics, situps, pullups
Slow twith: type A
minimal force, long fatigability
swimming, cycling, marathon, rowing
Iso
same
