Resistance Exercise for Impaired
Muscle Performance
An introduction
Intro....
• Muscle performance refers to the capacity of a muscle
to do work (force x distance).
• key elements of muscle performance:
– strength
– power
– Endurance
Definition of Resistance exercise
• Any form of active exercise in which dynamic or static
muscle contraction is resisted by an outside force
applied manually or mechanically
Important terms
 Strength
 Strength is the ability of contractile tissue to produce
tension and a resultant force based on the demands placed
on the muscle.
Strength training (strengthening exercise)
• It is a systematic procedure of a muscle or muscle
group lifting, lowering, or controlling heavy loads
(resistance) for a relatively low number of repetitions
or over a short period of time.
increase in muscle fiber size.
increase in the maximum force-producing
capacity of muscle
Power
• Power is the work produced by a muscle per unit of
time
– In other words  the rate of performing work.
• Power can be enhanced by 2 ways !!
– increasing the work a muscle must perform during a
specified period of time
– reducing the amount of time required to produce a given
force.
Endurance
• Endurance is the ability to perform low-intensity, repetitive,
or sustained activities over a prolonged period of time
• Cardiopulmonary endurance
– repetitive, dynamic motor activities such as walking, cycling,
swimming, or upper extremity ergometry, which involve use of
the large muscles of the body.
• Muscle endurance - sustained control
– the ability of a muscle to contract repeatedly against a load
(resistance), generate and sustain tension, and resist fatigue
over an extended period of time.
– Eg :Maintenance of balance and proper alignment of the
body segments
almost all daily living tasks require some degree of
muscle and cardiopulmonary endurance.
Endurance
• Endurance training:
– characterized by having a muscle contract and lift or lower
a light load for many repetitions or sustain a muscle
contraction for an extended period of time.
– The key elements of endurance training are low-intensity
muscle contractions, a large number of repetitions, and a
prolonged time period.
Types of Resistance Exercise
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Manual and Mechanical Resistance Exercise
Isometric Exercise (Static Exercise)
Dynamic Exercise—Concentric and Eccentric
Dynamic Exercise—Constant and Variable
Resistance
• Isokinetic Exercise
• Open-Chain and Closed-Chain Exercise
Manual Resistance Exercise
• type of active-resistive exercise in which resistance is
provided by a therapist
– May be applied in a self-resistance form
• in the early stages of an exercise program
• when the range of joint movements needs to be carefully
controlled
• The amount of resistance given is limited only by the
strength of the therapist.
Mechanical Resistance Exercise
• active-resistive exercise in which resistance is applied
through the use of equipment or mechanical
apparatus.
• Resistance can be measured quantitatively and
incrementally progressed over time
• useful when the amount of resistance necessary is
greater than what the therapist can apply manually.
Isometric Exercise (Static Exercise)
• Isometric exercise is a static form of exercise in which
a muscle contracts and produces force without an
appreciable change in the length of the muscle and
without visible joint motion.
• an isometric contraction should be held for 6
seconds and no more than 10 seconds
• Types of Isometric Exercise:
– Muscle-setting exercises
– Stabilization exercises
– Multiple-angle isometrics
Muscle-setting exercises:
• low-intensity isometric contractions performed against
little to no resistance
• used to:
– decrease muscle pain and spasm
– promote relaxation and circulation after injury to soft tissues
during the acute stage of healing
Stabilization exercises:
• used to develop a submaximal but sustained level of
co-contraction to improve postural stability or
dynamic stability of a joint
Multiple-angle isometrics:
• A system of isometric exercise where resistance is
applied at multiple joint positions within the
available ROM
• used when the goal of exercise is to improve strength
throughout the ROM when joint motion is permissible but
dynamic resistance exercise is painful or inadvisable.
Dynamic Exercise—Concentric and
Eccentric
Open-Chain and Closed-Chain Exercise
• Open-Chain :
– motions in which the distal segment
(hand or foot) is free to move in space,
without necessarily causing simultaneous
motions at adjacent joints.
• Closed-Chain:
– motions in which the body moves on a
distal segment that is fixed or stabilized
on a support surface
Advantages of Resistance Exercise
• Enhanced muscle performance: restoration,
improvement or maintenance of muscle strength,
power, and endurance
• Increased strength of connective tissues: tendons,
ligaments, intramuscular connective tissue
• Greater bone mineral density or less bone
demineralization
• Enhanced physical performance during daily living,
occupational, and recreational activities
• Enhanced feeling of physical well-being
1. Overload Principle
• If muscle performance is to improve, A load that exceeds the
metabolic capacity of the muscle must be applied; that is, the
muscle must be challenged to perform at A level greater than
that to which it is accustomed.
Application of the Overload Principle
focuses on the progressive loading of muscle by changing in 2
factors:
• Intensity of resistance.
• Volume(repetition, sets, frequency).
In a strength training program, the amount of resistance applied to
the muscle is incrementally and progressively increased.
For endurance training, more emphasis is placed on increasing the
time a muscle contraction is sustained or the number of repetitions
performed than on increasing resistance.
2. Specific adaptation to imposed demands
(SAID Principle)
• The SAID principle helps therapists determine the
exercise prescription and which parameters of
exercise should be selected to create specific training
effects that best meet specific functional needs and
goals.
a. Specificity of Training
• the adaptive effects of training are highly specific to the
training method employed
– exercises incorporated in a program should mimic the
anticipated function
• Consider the mode (type) and velocity of exercise as well as
patient or limb position and the movement pattern during
exercise.
– task-specific practice must always be emphasized
– Ex: ascending and descending stairs.
b. Transfer of Training
• carryover of training effects from one variation of
exercise or task to another
c. Reversibility Principle
 Adaptive changes in the body's systems in response to
a resistance exercise program are transient .
 Detraining, reflected by a reduction in muscle
performance, begins within a week or two after the
cessation of resistance exercises
Fatigue
• a complex phenomenon that affects muscle
performance and must be considered in a resistance
training program.
Muscle (local) fatigue
• This occurs during exercise when a muscle repeatedly contracts
statically or dynamically against an imposed load.
• This acute physiological response to exercise is normal and
reversible.
Cardiopulmonary (general) fatigue
• the diminished response of an individual as the
result of prolonged physical activity.
– related to the body's ability to use oxygen efficiently
• Caused by a combination of the following factors:
– Decrease in blood sugar (glucose) levels
– Decrease in glycogen stores in muscle and liver
– Depletion of potassium, especially in the elderly patient
Factors that influence fatigue
•
•
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A patient's health status
Diet
Lifestyle (sedentary or active)
Environmental factors !!
Determinants of Resistance
Exercise
1. Alignment
• Alignment and muscle action. Proper alignment is
determined by the direction of muscle fibers and the
line of pull of the muscle to be strengthened.
• Alignment and gravity. The patient or limb should be
positioned so the muscle being strengthened acts
against the resistance of gravity and the weight.
2. Stabilization
Goals:
• To maintain appropriate alignment.
• ensure the correct muscle action and movement pattern.
• Avoid unwanted substitute motions during resistance
exercise.
Types of stabilization:
• External: by therapist or patient’s hand or by equipment such
as belt.
• Internal: is achieved by an isometric contraction of an
adjacent muscle group that does not enter into the
movement pattern.
This form of stabilization is effective only if the fixating muscle
group is strong enough or not fatigued.
3. Intensity
• The amount of resistance (weight) imposed on
the contracting muscle during each repetition
of an exercise.
– also referred to as the exercise load (training load)
Submaximal Versus Maximal Exercise Loads
Submaximal loading. Exercise at moderate to low intensities is
indicated:
• At the beginning of an exercise program.
• In the early stages of soft tissue healing.
• After periods of immobilization.
• For most children or older adults
• When the goal of exercise is to improve muscle endurance
• To warm up and cool down prior to and after a session of
exercise
• During slow-velocity isokinetic training to minimize
compressive forces on joints
Near maximal or maximal loading. High-intensity
exercise is indicated:
• When the goal of exercise is to increase muscle
strength and power and possibly increase muscle
size.
• in the advanced phase of a rehabilitation program.
• In a conditioning program for individuals with no
known pathology
• For individuals training for competitive weight lifting
or body building
Repetition Maximum (RM)
• Greatest amount of weight a muscle can move through
the available ROM a specific number of times
Reasons of use of RM
– to document a baseline measurement of the dynamic
strength of a muscle
– to identify an exercise load (amount of weight) to be
used during exercise for a specified number of
repetitions.
Repetition Maximum
• 1 RM: the greatest amount of weight a subject
can lift through the available ROM just one time.
– baseline measurement of a subject's maximum effort
• 10 RM: the amount of weight that could be lifted
and lowered exactly 10 times during training.
Alternative Methods of Determining Baseline Strength and a
Beginning Exercise Load
Isokinetic
Dynamometer
Cable
Tensiometry
Handheld
Dynamometer
Exercise Order
• The sequence in which exercises are performed
during an exercise session has an impact on
muscle fatigue and the adaptive training effects.
• large muscle groups should be exercised before
small muscle groups and multijoint muscles
before single-joint muscles.
• higher intensity exercises should be performed
before lower intensity exercises.
Frequency
• Number of exercise sessions per day or per week.
• for a maintenance program, two times per week.
• With prepubescent children and the very elderly,
frequency is usually limited to two to three sessions
per week.
• Highly trained athletes train at a high intensity and
volume up to 6 days per week.
Duration
• total number of weeks or months during
which a resistance exercise program is carried
out.
• strength gains, (after 2 to 3 weeks) are the
result of neural adaptation.
• For hypertrophy or increased vascularization,
at least 6 to 12 weeks of resistance training is
required.
Rest Interval (Recovery Period)
• Purpose
– allow time for the body to recuperate from the acute
effects of exercise associated with muscle fatigue or to
offset adverse responses, such as DOMS.

The higher the intensity of exercise the longer the rest
interval.
◦ 4 to 5 minutes with high-intensity resistance training, large,
multijoint muscles, such as the hamstrings
◦ 2-3min rest period after each set with moderate-intensity resistance
training
◦ A shorter rest interval is adequate after low-intensity exercise
Mode of Exercise
• The form of exercise, the type of muscle
contraction that occurs and the manner in which
the exercise is carried out.
– Type of Muscle Contraction
– Position for Exercise
– Energy Systems
– Range of Movement
Training Zone
• 30% to 40% of 1RM for sedentary untrained individuals
• 60% to 70% of 1RM For healthy but untrained adults
• 80% to 95% of 1RM for those already highly trained.
– Exercising at a low to moderate percentage of the
established RM is also recommended for children and the
elderly.
– For patients with significant deficits in muscle strength or to
train for muscular endurance, using a low load, possibly at
the 30% to 50% level, is safe yet challenging.
Volume
• The summation of the total number of
repetitions and sets of a particular exercise
during a single exercise session multiplied by the
resistance used
– rep.x set x r
Repetitions.
• The number of times a particular movement is repeated.
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A predetermined number of repetitions grouped
together
After each there is a brief interval of rest.
Single-set exercises at low intensities in the early
phases of a resistance exercise program or in
maintenance program.
Multiple-set exercises are used to progress the
program
How to determine exercise load??
• The question is: Is the goal to improve
strength, muscular endurance, or both?
• To Improve Muscle Strength
• DeLorme's studies 3 sets of a 10 RM
performed for 10 repetitions over the training
period led to gains in strength.
• To Improve Muscle Endurance
• many repetitions of an exercise against a
submaximal load.
• three to five sets of 40 to 50 or more
repetitions against a low amount of weight or
a light grade of elastic resistance
• When increasing the number of repetitions or
sets becomes inefficient, the load can be
increased slightly.
GENERAL PRINCIPLES OF
RESISTANCE TRAINING
Examination and Evaluation
• Comprehensive
• Re-evaluate periodically
– document progress
– determine if and how the dosage of exercises and the
types of resistance exercise should be adjusted to continue
to challenge the patient.
Preparation for Resistance Exercises
• Select the forms of resistance exercise
– Manual resistance exercises
– Mechanical resistance exercises.
• With mechanical resistance exercise, determine what
equipment is needed and available.
• Review the anticipated goals and expected functional
outcomes.
Application of Resistance Exercises
• Warm Up
– light, repetitive, dynamic, site-specific movements without
applying resistance.
• Placement of Resistance
• typically applied to the distal end of the segment in
which the muscle to be strengthened attaches.
• May be applied across an intermediate joint if that joint
is stable and pain-free and if there is adequate muscle
strength supporting the joint
typical
possible
Application of Resistance Exercises
• Direction of Resistance
– During concentric exercise resistance is applied in the
direction directly opposite to the desired motion
– during eccentric exercise resistance is applied in the same
direction as the desired motion
• Stabilization
– Stabilization is necessary to avoid unwanted, substitute
motions.
Application of Resistance Exercises
• Intensity of Exercise/Amount of Resistance
– Initially, have the patient practice the movement pattern
against a minimal load to learn the correct pattern and the
exercise technique.
– Have the patient exert a forceful but controlled and painfree effort.
– Adjust the alignment, stabilization, or the amount of
resistance if necessary
Precautions for Resistance Exercise
• Keep the temperature of the room comfortable for vigorous
exercise.
• Caution the patient that pain should not occur during
exercise.
• Do not initiate resistance training at a maximal level of
resistance, particularly with eccentric exercise to minimize
delayed-onset muscle soreness (DOMS).
• Avoid use of heavy resistance during exercise for children,
older adults, and patients with osteoporosis.
Precautions for Resistance Exercise
• Do not apply resistance across an unstable joint or distal to a
fracture site that is not completely healed.
• Avoid breath-holding during resisted exercises to prevent the
Valsalva maneuver; emphasize exhalation during exertion.
• Avoid exercises that place excessive, unintended secondary
stress on the back.
• Discontinue (stop) exercises if the patient experiences pain,
dizziness, or unusual or precipitous shortness of breath.
Valsalva Maneuver
• An expiratory effort against a closed glottis that must
be avoided during resistance exercise
deep
inspiration
closure of the glottis
contraction of the abdominal
muscle
abrupt, temporary increase in arterial
blood pressure
increases intraabdominal and
intrathoracic
pressures
forcing blood from
the heart
Substitute Motions
• attempt to carry out the desired movements that the weak
muscles normally perform by any means possible
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–
–
–
–
muscles weakness
Fatigue
Paralysis
Pain
Severe Cardiopulmonary Disease
• an appropriate amount of resistance must be applied,
• correct stabilization
Contraindications
• Acute inflammation.
• Acute diseases and disorders.
• Pain
• adverse effects from resistance training can be
avoided by:
– carefully selecting the appropriate mode of exercise
– keeping the initial intensity of the exercise at a very low to
moderate level
Overtraining
• Over training is the decline in physical
performance in healthy individuals
participating in high-intensity, high-volume
strength and endurance training programs.
• fatigue become more quickly and requires
more time to recover from strenuous exercise
Overtraining
• Causes:
– inadequate rest intervals between exercise sessions
– too rapid progression of exercises
– Inadequate diet and fluid intake
• It is a preventable, reversible phenomenon
– decreasing the volume and frequency of exercise
(periodization).
Overwork
• Over work is progressive deterioration of strength in
muscles already weakened by nonprogressive
neuromuscular disease.
• Prevention:
Monitor patients closely
Progress slowly and cautiously
re-evaluate frequently
 Patients should not exercise to exhaustion and should be
given longer and more frequent rest intervals during and
between exercise sessions.
Exercise-Induced Muscle Soreness
• Acute Muscle Soreness:
• Delayed-Onset Muscle Soreness:
Acute Muscle Soreness:
• Acute muscle soreness develops during or directly
after strenuous exercise performed to the point of
muscle exhaustion.
• Due to lack of adequate blood flow and oxygen and a
temporary buildup of metabolites
• burning or aching pain in the muscle.
– transient and subsides quickly after exercise
– An appropriate cool-down period of low-intensity exercise
can facilitate this process.
Delayed-Onset Muscle Soreness
(DOMS):
• Due vigorous and unaccustomed resistance training or
any form of muscular overexertion
– Noticeable in the muscle belly or at the myotendinous
junction
• begins to develop approximately 12 to 24 hours after
the cessation of exercise.
• High-intensity eccentric muscle contractions
consistently cause the most severe DOMS symptoms.
• the signs and symptoms, which can last up to 10 to 14
days, gradually dissipate.
Signs and Symptoms of DOMS
• beginning 12 to 24 hours after exercise and
peaking at 48 to 72 hours
• Tenderness with palpation throughout the
involved muscle belly or at the myotendinous
junction
• Increased with passive lengthening or active
contraction of the involved muscle
Signs and Symptoms of DOMS
• Local oedema and warmth
• Muscle stiffness: reflected by spontaneous
muscle shortening before the onset of pain
• Decreased ROM
• Decreased muscle strength: prior to onset of
muscle soreness that persists for up to 1 to 2
weeks after soreness has remitted.
Prevention and treatment of DOMS:
• Continuation of a training program that has
induced DOMS
• Light, high-speed (isokinetic), concentric exercise
• Electrical stimulation
• cryotherapy
• post-exercise massage
• compression sleeve
• topical salicylate creams provide an analgesic effect