Lecture 12 Flashcards
Isometric
contraction without motion
force is product
Concentric
dynamic
shortening contraction
Eccentric
dynamic
lengthening contraction
Isokinetic
concentric or eccentric contraction with constant velocity (speed and direction)
Good muscle function is made up of…
power
strength
endurance
each are improved with resistance training
Torque
force x moment arm
the ability of a force to produce rotation
Moment arm
perpendicular distance from the line of action of the force to the axis of rotation
Torque can be altered by
changing force magnitude
changing moment arm length
changing angle between of force and moment arm
Power
rate of performing work
power = work/time
power is different from endurance or strength because of the time component
Work
magnitude of force acting on an object multiplied by the distance through which the force acts
work = force x distance
Force
agent that produces or tends to produce a change in the state of rest or motion of an object
force = mass x acceleration
Power can be gained by
increasing the work done in a specific period of time
reducing the amount of time required to produce the work
maintaining BMD
power training
did not lead to increased injury or pain
Strength
maximum force that a muscle can develop during a single muscle contraction
all are needed for strength–neurological, muscular, biomechanical, cognition/affect
Strength training research
exercise intervention programs should be individualized to specifically target muscle mass, strength, and functional capacity
resistance and impact exercise is superior to stretching at improving maximal muscle strength
Endurance
the ability of a muscle to sustain forces repeatedly or to generate forces over an extended period of time without fatigue
can be over TIME or repeat contractions
Endurance training research
high-intensity circuit training showed reductions in health causing problems like LDL
Overload principle
a muscle must be challenged to perform at a level greater than that to which it is accustomed
if the demands remain constant after the muscle has adapted, the level of muscle performance can be maintained but not increased
SAID principle
Specific Adaptation to Imposed Demands
specificity is a necessary foundation on which exercise programs should be built
Wolff’s law
body systems adapt over time to the stressed placed on them. bone and muscle growth
Reversibility principle
adaptive changes are transient unless training-induced improvements are regularly used for functional activities or maintenance program
if you don’t use it, you lose it
Gains begin to….
decrease in 1-2 weeks after stopping exercise
Determinants of Resistance Exercise Program
alignment
stabilization
intensity
sequence
volume
frequency
duration
mode
Alignment
segments with emphasis on fiber orientation
Stabilization
proximal or distal joints to prevent substitution/form faults
Sequence of exercises
Specific patient population: isolated training, isometric/dynamic, single/multi joints, slow to fast speed
General: multi-joint exercises for strength and power gains
Intensity
exercise load/level or resistance
based on goals, extent of impairment, stage of healing, age/general health/fitness level
document –> 10#
Volume
total number of repetitions and sets in an exercise session
sets, repetition
Repetition
of reps dependent on status and goals
single performance of specific exercise
often within a range rather than exact number
number of reps dependent on pt status and goals
document: 4/15 (4 sets of 15 reps)
Sets
predetermined number of consecutive repetitions that are grouped together
separated timed rest
fatigue is the GOAL, if its not achieved, the intensity is too low
document: 4/15 (4 sets of 15 reps)
Repetition maximum
greatest amount of weight a muscle can move through the full available ROM, with control, for a specific # of times before fatiguing
If you want strength…
1-5 reps per set
80-90% of 1RM
If you want growth…
6-12 reps per set
60-80% of 1 RM
If you want endurance…
15+ reps per set
>40% of 1 RM
Frequency
number of exercise sessions per day or per week
determined by intensity/volume, goals, health status, previous experiences, response to training
document: 4x/wk
Duration
exercise is a long-term investment
strength gains early on (2-3 weeks) are based on neural adaptation
have to go for 6-12 weeks of resistance training
Mode
form of exercise, the type of muscle contraction that occurs, manner in which exercise is carried out
Muscle fatigue
diminished response to exercise due to decreased energy stores, insufficient oxygen, reduced sensitivity, and availability of intracellular calcium, and build-up of H+
Signs of muscle fatigue
pain, cramping
shaking
slowing of movement
movements are jerky
can’t move through full ROM
compensating
Manual resistance
external force is provided by a therapist. Force can be applied to achieve an isometric, concentric or eccentric contraction.
Uses of manual resistance
early stages of an exercise program when the muscle to be strengthened is weak and can overcome only minimal to moderate resistance
when the range of joint movements needs to be carefully controlled
