Download Managing Impaired Muscle

Chapter 6
Managing Impaired Muscle
Performance
Overview


Muscle is the only biological tissue
capable of actively generating tension
This characteristic enables human
skeletal muscle to perform the
important functions of maintaining
upright body posture, moving body
parts, and absorbing shock
Skeletal Muscle

Skeletal muscle possesses four
biomechanical properties:
– Extensibility: the ability to be stretched or to
increase in length
– Elasticity: the ability to return to normal resting
length following a stretch
– Irritability: the ability to respond to a stimulus
– The ability to develop tension. The ability of
skeletal muscle to develop tension is referred to
as a contraction
Muscles


An agonist muscle contracts to produce the
desired movement
An antagonist muscle opposes the desired
movement
– Antagonists resist the agonist movement by
relaxing and lengthening in a gradual manner to
ensure that the desired motion occurs, and that
it does so in a coordinated and controlled
fashion

Muscle groups that work together to
produce a desired movement, are called
synergists
Muscles


Most muscles span only one joint
However, there are many muscles in the
body that cross two or more joints:
–
–
–
–
–
The
The
The
The
The
erector spinae
biceps brachii
long head of the triceps brachii
hamstrings
rectus femoris
Development of Muscle
Tension

The magnitude of the tensile force
generated by a muscle is dependent on a
number of factors:











Type of contraction
The force-velocity relationship
The ability to recruit motor units
Electromechanical delay
Force-length relationship
Angle of insertion
Angle of pennation
Stored elastic capabilities
Gravity
Fatigue
Muscle temperature
Improving Muscle
Performance

Muscle performance can be measured using
a number of parameters:
– Strength: the ability of a muscle to generate
force against a specific resistance, or to produce
torque at a joint
– Endurance: the ability of a muscle to sustain or
perform repetitive muscular contractions for an
extended period
– Power: the product of muscular force and the
velocity of muscle shortening
Improving Muscle
Strength


To increase strength, the load or
resistance must be gradually increased
during the muscle contraction
Strengthening of a muscle occurs
when the muscle is forced to work at a
higher level than that to which it is
accustomed
Improving Muscle
Strength

If the metabolic capabilities of the muscle
are progressively overloaded, adaptive
changes occur within the muscle:
– An increase in the size of the muscle
(hypertrophy)
– An increase in the efficiency of the
neuromuscular system
– An enhancement of the muscle’s endurance
– An improvement in the power of the muscle
Improving Muscle
Strength

Four main types of strengthening
exercise:
– Isometric
– Concentric
– Eccentric
– “Functional”
Improving Muscle
Strength

The parameters that must be
considered when developing an
exercise program include:
– Intensity
– Duration
– Frequency
Improving Muscle
Endurance

To increase muscle endurance,
exercises are performed against light
resistance for many repetitions, so
that the amount of energy expanded
is equal to the amount of energy
supplied
Improving Muscle Power

Muscle power is increased by having a
muscle work dynamically against
resistance within a specified period
– Example: Plyometrics
Specificity of Training


Specificity of training involves the
principle of the Specific Adaptation to
Imposed Demand (SAID)
Aim: To improve the strength and
coordination of functional or sportsspecific movements with exercises that
approximate the desired activity
Increasing Flexibility


Flexibility training has long been
recognized as an essential component
of any conditioning program as a
means to prevent injury and improve
performance
Two broad types:
– Static
– Dynamic
Static and Dynamic
Flexibility


Static flexibility is defined as the
passive ROM available to a joint or
series of joints
Dynamic flexibility refers to the ease
of movement within the obtainable
ROM
Methods of Stretching




Passive
Static
Ballistic Stretching
Neuromuscular facilitation
Delayed Onset Muscle
Soreness


This type of soreness, which occurs
between 48-72 hours after exercise,
may last for up to 10 days
Prevention of this type of muscle
soreness involves careful design of the
eccentric program including prepatory
techniques, accurate training variables
and appropriate aftercare
Sarcopenia


Sarcopenia (sarco = muscle, penia = lack
of), is not a disease but rather refers
specifically to the universal, involuntary
decline in lean body mass that occurs with
age, primarily due to the loss of skeletal
muscle
When older people maintain muscular
activity, the losses in strength with age are
reduced substantially
Neuromuscular
facilitation

The proprioceptive neuromuscular
facilitation (PNF) techniques of holdrelax, stretch-relax, and agonist
contract-relax can be used to actively
stretch the soft tissues.
Neuromuscular
facilitation

Hold-relax – autogenic inhibition
– An isometric contraction of the range
limiting antagonist is performed against
slowly increasing resistance
– This is followed by a voluntary relaxation
by the patient and then passive
movement of the extremity by the
clinician
Neuromuscular
facilitation

Hold-relax-active – reciprocal inhibition
– Following application of the hold-relax
technique, the patient performs an active
contraction into the newly gained range
of the agonist pattern
Neuromuscular
facilitation

Contract relax
– And isotonic movement in rotation is
performed followed by an isometric hold
of the range limiting muscles in the
antagonist pattern against slowly
increasing resistance, voluntary
relaxation, and active movement into the
new range of the agonist pattern
Aquatic exercise

The indications for aquatic therapy
include instances when:
– Partial weight bearing ambulation is
necessary
– To increase range of motion
– When standing balance needs to be
improved
– When endurance/aerobic capacity needs
to be improved
Aquatic exercise

Contraindications include incontinence,
urinary tract infections, unprotected
open wounds, heat intolerance, severe
epilepsy, uncontrolled diabetes,
unstable blood pressure or severe
cardiac, and/or pulmonary dysfunction
Aquatic exercise

Pool temperatures should be:
– 92 to 95°F for water exercise
– 85 to 90°F for active swimming
– 82.4 to 89.6°F for light activity