Transcript Flexibility

Flexibility
Flexibility

Optimal musculoskeletal
function requires that an
adequate range of motion
be maintained in all joints.
Flexibility
 Identify
those joints and muscle groups which are
in need of improvement and select an appropriate
exercise mode and specific exercises for the
flexibility program.
Flexibility

The specificity and
progressive overload
principles apply to the
design of flexibility
programs.
Flexibility

Flexibility is highly jointspecific; therefore, to
increase flexibility of a
particular joint, select
exercises that stretch the
appropriate muscle
groups.
Flexibility
 To
improve ROM at the joint, your client must
overload the muscle group by stretching the
muscles beyond their normal resting length - but
never beyond the pain-free range of motion.
Flexibility
 Periodically
your client will need to increase both
the amount of time the stretched position is
maintained and the number of repetitions of the
exercise to ensure the overload required for further
improvement.
Flexibility
 Of
particular importance is maintenance of
flexibility in the lower back and posterior thigh
regions.
 See next set of notes on back health.
Flexibility
 Lack
of flexibility in this area may be associated
with an increased risk for the development of
chronic lower back pain.
Flexibility
 Lack
of flexibility is prevalent in the elderly
among whom this condition often contributes to a
reduced ability to perform activities of daily living
(ADL).
Flexibility
 Accordingly,
exercise programs for the elderly
should emphasize proper stretching, especially for
the upper and lower trunk, neck, and hip regions.
Flexibility

There are different types
of stretching techniques
(e.g., static, ballistic, and
PNF) that can be
performed.
Flexibility

All three types of
stretching are effective in
increasing the ROM.
PNF
 PNF
stretching increases ROM by inducing
muscle relaxation through spinal reflex
mechanisms.
PNF
 Using
the contract-relax technique, your client
first performs an isometric contraction of the
muscle group being stretched, and then proceeds
with the slow, static stretching (relaxation phase)
of the muscle group.
PNF
 This
technique is based on the concept of
reciprocal inhibition.
 Contraction
another.
on one muscle causes relaxation in
PNF
 Theoretically,
the isometric contraction of the
antagonists (muscle group being stretched)
induces a reflex facilitation and contraction of the
agonist during the slow, static stretching phase.
PNF
 The
isometric contraction of the antagonists also
stimulates the Golgi tendon organs, resulting in a
reflex relaxation of the same muscle group.
PNF
 Another
type of PNF stretching is the contractrelax with agonist contraction (CRAC) technique.
PNF
 This
method is identical to the contract-relax
technique except that the stretching is assisted by
a submaximal contraction of the opposing
(agonist) muscle group.
PNF
 Theoretically,
the voluntary contraction of the
agonists induces additional inhibitory input to the
antagonists (muscles being stretched) through
reciprocal inhibition.
Steps for PNF Stretching
 1.
Stretch the target muscle group by moving the
joint to the end of its ROM.
 2.
Isometrically contract the pre-stretched muscle
group against an immovable resistance (such as a
partner or wall) for 5 to 6 seconds.
Steps for PNF Stretching
 3.
Relax the contracted muscle group as you or
your partner statically stretch the muscle to a new
point of limitation.
Steps for PNF Stretching
 4.
With the contract-relax agonist contraction
technique, the opposing muscle group, (agonist)
contracts submaximally for 5 to 6 seconds to
facilitate relaxation and further stretching of the
target muscle group.
Static Stretching vs Ballistic Stretching
 Many
exercise specialists recommend using slow,
static stretching rather than ballistic stretching
because there is more chance of injury and muscle
soreness resulting from jerky, rapid movements.
Static Stretching vs Ballistic Stretching

The ballistic technique
uses a relatively fast,
bouncing motion to
produce stretch.
Static Stretching vs Ballistic Stretching

The momentum of the
moving body segment,
rather than external force,
pushes the joint beyond its
present ROM.
Static Stretching vs Ballistic Stretching
 This
technique appears to be counterproductive for
increasing muscle stretch.
 Muscle
spindles signal both changes in length and
speed of contraction.
Static Stretching vs Ballistic Stretching
 The
spindle responds more to the speed of
movement than to the muscle’s length or position.
 In
fact, muscle spindle activity is directly
proportional to the speed of movement.
Static Stretching vs Ballistic Stretching
 Thus,
ballistic stretching evokes the stretch reflex,
producing more contraction and resistance to
stretch in the muscle group being stretched.
Static Stretching vs Ballistic Stretching
 This
places strain on the muscle-tendon unit and
may cause microscopic tearing of muscle fibers
and connective tissue.
Static Stretching vs Ballistic Stretching

In slow, static stretching,
your client stretches the
muscle with the joint
positioned at the end of its
ROM.
Static Stretching vs Ballistic Stretching
 While
maintaining this position, the client slowly
applies torque to the muscle to stretch it further.
 Because the dynamic portion of the muscle
spindle rapidly adapts to the lengthened position,
the spindle discharge is decreased.
Static Stretching vs Ballistic Stretching
 This
lessens reflex contraction of the muscle and
allows the muscle to relax (viscoelastic stress
relaxation) and to be stretched even further.
Is PNF stretching better than slow,
static stretching?
 Limited
 It
research.
may be, but it produces greater feelings of being
uncomfortable.
PNF Stretching vs Static Stretching
A
major disadvantage of the PNF technique is that
the exercises, in some cases, cannot be performed
alone.
PNF Stretching vs Static Stretching
A
partner is needed to resist movement during the
isometric contraction phase and to apply external
force to the muscle during the stretching phase.
PNF Stretching vs Static Stretching
 Thus,
the amount of time required for both
individuals to complete the flexibility exercises is
increased.
Comparison of Stretching Techniques

See table 11.1, p. 284,
Heyward Book
Exercise Program for Flexibility

A well-rounded program
includes at least one
exercise for each of the
major muscle groups of
the body.
Exercise Program for Flexibility
 Use
the results of the flexibility tests to identify
specific muscle groups with relatively poor
flexibility, and include more than one exercise for
these muscle groups.
Exercise Program for Flexibility

A general exercise
program for achieving and
maintaining flexibility
should adhere to the
following guidelines:
Flexibility
F
= At least 3 days/week, preferably daily.
 I = To a position of mild discomfort.
 Slowly
T
= 15 to 30 secs. for each stretch.
 Not
S
elongate to low force hold.
much improve beyond 30 secs.
= 3 to 5 reps for each stretch. Perform static
stretches and/or PNF with a major emphasis on
the lower back and thigh area.
Safe Intensity?
 The
joint should not be stretched beyond its painfree range of motion.
 Some mild discomfort will occur.
Duration of Stretch?
 ACSM
recommends holding the stretched position
only as long as it feels comfortable (usually 15 to
30 seconds).
Number of Repetitions?
 Beginners
should start with 3 reps of each
exercise.
 As flexibility improves, they may increase the
reps to 5.
Flexibility
Tips
 Perform in an unloaded body position.
 Stretch muscles, not ligaments.
 Focus on problem areas.
 Target “normal” static range of motion.
 Extreme
stretching causes increased risk of injury.
Flexibility
Tips
 Emphasize active warm-up prior to stretching.
 Stretch during cool down.
 Focus on areas of increased static range of motion
demand.
Tips
 Focus
on the target muscle involved in the stretch,
relax the target muscle, and minimize the
movement of other body parts.
Tips
 Stretch
to the limit (endpoint) of the movement,
not to the point of pain.
Tips
 Keep
breathing slowly and rhythmically while
holding the stretch.
 Stretch
the target muscle groups in different
planes to improve overall ROM at the joint.
Risky Exercises?
 Hyperextension
 Hyperflexion