Download Stretch

chapter
Warm-Up and Stretching
13
Warm-Up
and Stretching
Ian Jeffreys, MS; CSCS,*D; NSCA-CPT,*D
Chapter Objectives
• Identify the benefits and components of a
preexercise warm-up.
• Assess the suitability of performing stretching exercises for a warm-up.
• Identify factors that affect flexibility.
(continued)
Chapter Objectives (continued)
• Describe flexibility exercises that take
advantage of proprioceptive neuromuscular
facilitation.
• Explain the mechanisms that cause the
muscular inhibition that improves the
stretch.
• Select and apply appropriate static and
dynamic stretching methods.
Section Outline
• Warm-Up
– Stretching During Warm-Up
– Components of a Warm-Up
Warm-Up
• Warming up can have the following positive
impacts on performance:
– Faster muscle contraction and relaxation of both
agonist and antagonist muscles
– Improvements in the rate of force development and
reaction time
– Improvements in muscle strength and power
– Lowered viscous resistance in muscles
(continued)
Warm-Up
• Warming up can have the following positive
impacts on performance (continued):
– Improved oxygen delivery due to the Bohr effect
whereby higher temperatures facilitate oxygen
release from hemoglobin and myoglobin
– Increased blood flow to active muscles
– Enhanced metabolic reactions
Warm-Up
• Stretching During Warm-Up
– Research suggests dynamic stretching is the
preferred option for stretching during warm-up.
– Consider the range of motion and stretch-shortening
cycle requirements of the sport when designing a
warm-up.
Warm-Up
• Components of a Warm-Up
– A general warm-up period may consist of 5 to 10
minutes of slow activity such as jogging or skipping.
– A specific warm-up period incorporates movements
similar to the movements of the athlete’s sport. It
involves 8 to 12 minutes of dynamic stretching
focusing on movements that work through the range
of motion required for the sport.
Section Outline
• Flexibility
– Flexibility and Performance
– Factors Affecting Flexibility
•
•
•
•
•
•
Joint Structure
Age and Sex
Connective Tissue
Resistance Training With Limited Range of Motion
Muscle Bulk
Activity Level
– Frequency, Duration, and Intensity of Stretching
– When Should an Athlete Stretch?
– Proprioceptors and Stretching
Flexibility
• Flexibility is a measure of range of motion
(ROM) and has static and dynamic components.
• Static flexibility is the range of possible
movement about a joint and its surrounding
muscles during a passive movement.
• Dynamic flexibility refers to the available
ROM during active movements and
therefore requires voluntary muscular
actions.
Flexibility
• Flexibility and Performance
– Optimal levels of flexibility exist for each activity.
– Injury risk may increase outside this range.
Flexibility
• Factors Affecting Flexibility
– Joint Structure
• Structure determines the joint’s range of motion.
– Age and Sex
• Older people tend to be less flexible than younger people;
females tend to be more flexible than males.
– Connective Tissue
• Elasticity and plasticity of connective tissues affect ROM.
(continued)
Flexibility
• Factors Affecting Flexibility (continued)
– Resistance Training With Limited Range of Motion
• Exercise through a full ROM and develop both agonist and
antagonist muscles to prevent loss of ROM.
– Muscle Bulk
• Large muscles may impede joint movement.
– Activity Level
• An active person tends to be more flexible than an inactive
one, but activity alone will not improve flexibility.
Flexibility
• Frequency, Duration, and Intensity of
Stretching
– Acute effects of stretching on ROM are transient.
– For longer-lasting effects, a stretching program is
required.
Flexibility
• When Should an Athlete Stretch?
– Following practice and competition
• Postpractice stretching facilitates ROM improvements
because of increased muscle temperature.
• Stretching should be performed within 5 to 10 minutes
after practice.
• Postpractice stretching may also decrease muscle
soreness although the evidence on this is ambiguous.
Flexibility
• When Should an Athlete Stretch?
– As a separate session
• If increased levels of flexibility are required, additional
stretching sessions may be needed.
• In this case, stretching should be preceded by a thorough
warm-up to allow for the increase in muscle temperature
necessary for effective stretching.
• This type of session can be especially useful as a recovery
session on the day after a competition.
Flexibility
• Proprioceptors and Stretching
– Stretch reflex
• A stretch reflex occurs when muscle spindles are
stimulated during a rapid stretching movement.
• This should be avoided when stretching, as it will limit
motion.
Flexibility
• Proprioceptors and Stretching
– Autogenic inhibition and reciprocal inhibition
• Autogenic inhibition is accomplished via active contraction
before a passive stretch of the same muscle.
• Reciprocal inhibition is accomplished by contracting the
muscle opposing the muscle that is being passively
stretched.
• Both result from stimulation of Golgi tendon organs, which
cause reflexive muscle relaxation.
Section Outline
• Types of Stretching
–
–
–
–
Static Stretch
Ballistic Stretch
Dynamic Stretch
Proprioceptive Neuromuscular Facilitation Stretch
•
•
•
•
Hold-Relax
Contract-Relax
Hold-Relax With Agonist Contraction
Common PNF Stretches With a Partner
Types of Stretching
• Static Stretch
– A static stretch is slow and constant, with the end
position held for 30 seconds.
• Ballistic Stretch
– A ballistic stretch typically involves active muscular
effort and uses a bouncing-type movement in which
the end position is not held.
• Dynamic Stretch
– A dynamic stretch is a type of functionally based
stretching exercise that uses sport-specific movements to prepare the body for activity.
Types of Stretching
• Proprioceptive Neuromuscular Facilitation
(PNF) Stretch
– Hold-Relax
• Passive prestretch (10 seconds), isometric hold
(6 seconds), passive stretch (30 seconds)
Positions for PNF Hamstring Stretch
• Figures 13.1 and 13.2 (next slide)
– Starting position of PNF hamstring stretch
– Partner and subject leg and hand positions for PNF
hamstring stretch
Figures 13.1 and 13.2
Hold-Relax
• Figures 13.3, 13.4, and 13.5 (next slide)
– Passive prestretch of hamstrings during hold-relax
PNF hamstring stretch
– Isometric action during hold-relax PNF hamstring
stretch
– Increased ROM during passive stretch of hold-relax
PNF hamstring stretch
Figures 13.3, 13.4, and 13.5
Types of Stretching
• Proprioceptive Neuromuscular Facilitation
Stretch
– Contract-Relax
• Passive prestretch (10 seconds), concentric muscle action
through full ROM, passive stretch (30 seconds)
Contract-Relax
• Figures 13.6, 13.7, and 13.8 (next slide)
– Passive prestretch of hamstrings during contractrelax PNF stretch
– Concentric action of hip extensors during contractrelax PNF stretch
– Increased ROM during passive stretch of contractrelax PNF stretch
Figures 13.6, 13.7, and 13.8
Types of Stretching
• Proprioceptive Neuromuscular Facilitation
Stretch
– Hold-Relax With Agonist Contraction
• During third phase (passive stretch), concentric action of
the agonist used to increase the stretch force
Hold-Relax With Agonist Contraction
• Figures 13.9, 13.10, and 13.11 (next slide)
– Passive prestretch during hold-relax with agonist
contraction PNF hamstring stretch
– Isometric action of hamstrings during hold-relax with
agonist contraction PNF hamstring stretch
– Concentric contraction of quadriceps during holdrelax with agonist contraction PNF hamstring
stretch, creating increased ROM during passive
stretch
Figures 13.9, 13.10, and 13.11
Key Point
• The hold-relax with agonist contraction is
the most effective PNF stretching technique
due to facilitation via both reciprocal and
autogenic inhibition.
Types of Stretching
• Proprioceptive Neuromuscular Facilitation
Stretch
– Common PNF Stretches With a Partner
•
•
•
•
•
•
Calf and ankle
Chest
Groin
Hamstrings and hip extensors
Quadriceps and hip flexors
Shoulder
Partner PNF Stretching
• Figures 13.12-13.16 (next two slides)
– Partner PNF stretching for the:
•
•
•
•
•
Calves
Chest
Groin
Quadriceps and hip flexors
Shoulders
Figures 13.12 and 13.13
Figures 13.14, 13.15, and 13.16
Types of Stretching
• Guidelines for Static Stretching
– Get into a position that facilitates relaxation.
– Move to the point in the ROM where you experience
a sensation of mild discomfort. If performing partnerassisted PNF stretching, communicate clearly with
your partner.
– Hold stretches for 30 seconds.
– Repeat unilateral stretches on both sides.
Types of Stretching
• Precautions for Static Stretching
– Decrease stretch intensity if you experience pain,
radiating symptoms, or loss of sensation.
– Use caution when stretching a hypermobile joint.
– Avoid combination movements that involve the spine
(e.g., extension and lateral flexion).
– Stabilizing muscles should be active to protect other
joints and prevent unwanted movements.
Types of Stretching
• Guidelines for Dynamic Stretching
– Carry out 5 to 10 repetitions for each movement,
either in place or over a given distance.
– Progressively increase the ROM on each repetition.
– Increase the speed of motion on subsequent sets
where appropriate.
– Contract the muscles as you move through the
ROM.
Types of Stretching
• Precautions for Dynamic Stretching
– Move progressively through the ROM.
– Move deliberately but without bouncing (movement
must be controlled at all times).
– Do not forsake good technique for additional ROM.