1. Flexibility

2. Learning Targets
I can define flexibility and the things that limit Range of Motion
I can explain the agonist/antagonist relationship between muscles
I can compare and contrast the 5 different stretching techniques
I can describe how to perform the 3 different PNF techniques
I can explain the neurophysiological basis for flexibility and stretching as it applies to each stretching technique

3. Flexibility Defined
Flexibility: the ability to move a joint or series of joints through a full, nonrestricted, pain-free range of motion
Can be discussed in relation to a single joint or a series of joints
Restricted range of motion can decrease performance capabilities
E.g. losing speed because hamstrings restrict hip flexion decreasing stride length; awkward or uncoordinated movement patterns

4. Factors that Limit Flexibility
Elasticity: tissue’s ability to return to its resting length
Extensibility: ability to stretch beyond a tissue’s normal length
Bony structure
Fat
Skin
Muscles and tendons
Connective tissue/contractures
Lose elasticity and shorten when immobilized

5. Active ROM Active ROM (also called Dynamic Flexibility)
Degree which a joint can be moved by a muscle contraction
Not a good indicator of flexibility because it applies to the ability to move a joint efficiently, with little resistance to motion.
Required to perform sporting activities
Need full knee extension to hurdle and for full stride length

6. Passive ROM Passive ROM (also called Static Flexibility)
Degree which a joint can be passively moved to the endpoints in the ROM.
No muscle contraction is involved.
Can move farther than active ROM
Important for injury prevention; allows muscle to stretch to prevent injury to the musculotendinous unit

7. Goniometry Goniometer A large protractor with measurement in degrees
Align individual arms of goniometer parallel with the longitudinal axis of the two segments involved in motion about a specific joint.

8. Stretching Techniques
Flexibility is important for successful physical performance and injury prevention
Goal of a flexibility program is to improve ROM at given articulation by altering extensibility of the musculotendinous unit that produce movement at that joint.

9. Stretching Techniques
Agonist v. Antagonist Muscles (Hero v. Villian)
Muscles that perform a specific action are called agonist muscles (e.g. quads perform knee extension)
Muscles that are being stretched in response to the contraction of the agonist are antagonist muscles (e.g. hamstrings stretched in knee extension)

10. Stretching Techniques
Muscles that work in concert with one another are called synergistic muscle groups (e.g. all four quadriceps muscles)
Balance must exist between agonist and antagonist muscles to allow for coordinated movement, as well as reduce the chance of muscle strain or imbalances.

11. Stretching Techniques: Ballistic
Ballistic Stretching
Bouncing movements; repetitive contractions of the agonist muscle are used to produce quick stretches of the antagonist muscle.
Concern that somewhat uncontrolled forces within the muscle may exceed extensibility limits in the muscle fiber, thus producing small microtears in the musculotendinous unit.

12. Stretching Techniques: Ballistic
May be true in sedentary or athletes with muscular injury but not usually a concern in healthy athletes.
Most sports are dynamic and require ballistic movements
e.g. forcefully kicking a soccer ball 50 times requires contraction of the quadriceps to extend the knee and requires the hamstrings to decelerate the lower leg via eccentric contractions. Ballistic stretching would prepare the hamstrings for this type of activity.

13. Stretching Techniques
Static Stretching
Involves passive stretching of the antagonist by placing it in a maximal position and holding it for an extended period of time.
Research has shown that holding a static stretch for 15 seconds is as effective as holding it for 2 minutes.
Research indicates that for maximal effectiveness over time static stretches should be repeated 3-5 times for each muscle being stretched.

14. Stretching Techniques
Static Stretching (continued)
Can be accomplished by using a contraction of the agonist muscle, body weight, a partner, or a T-bar or pole (primarily for upper body)
Research has shown that static and ballistic stretching are equally effective for improving flexibility, however there seems to be less danger of exceeding extensibility limits with static stretching.
Ballistic stretching is better indicated as part of a warm-up as it more mimics dynamic activity.

15. Stretching Techniques
Proprioceptive Neuromuscular Facilitation
Techniques called slow-reversal-hold-relax, contract-relax, and hold-relax
Utilize isotonic and isometric contractions and relaxation of both agonist and antagonistic muscles
Best with a partner but can be used with a wall for resistance.

16. Neurophysiological Basis of Stretching
All three techniques involve the neurophysiological phenomenon involving the stretch reflex.
Mechanoreceptors send messages to the CNS of what is happening to the muscle.
Two of the mechanoreceptors that are important in the stretch reflex are the muscle spindle and Golgi tendon organ.

17. Muscle Spindle Sensitive to changes in muscle length.
When a muscle is stretched sensory impulses are sent to the CNS informing it that the muscle is being stretched.
Return impulses from the spinal cord to the muscle causing the muscle to reflexively contract, thus resisting the stretch.
If the stretch continues for at least 6 seconds the Golgi Tendon Organ responds.

18. Golgi Tendon Organ
Affected by changes in muscle length and muscle tension.
If the stretch continues for at least 6 seconds the Golgi Tendon Organ responds by causing a reflex relaxation of the antagonist muscle
This protects the muscle and allows it to stretch through relaxation before extensibility limits are exceeded.

19. Neurophysiology Applied
Ballistic Stretching
Repetitive bouncing repeatedly stretch the Muscle Spindles
Ballistic stretching is not held long enough to allow the GTO to have a relaxing effect.
This stretching targets other tissues to help improve ROM
Static Stretching
Involves sustained stretch lasting from 6-60 seconds
This allows the GTO to respond to increased tension
GTO overrides impulses from Muscle Spindle allowing the muscle to relax.

20. Neurophysiology Applied
PNF
It takes advantage of the same neurophysiological principles and two additional techniques.
Autogenic Inhibition
A maximal isometric contraction of the muscle that will be stretched during a 10 second “push” phase increases tension that stimulates the GTO
This causes a reflexive relaxation response in the antagonist muscle even before it is placed into a stretched position
Relaxation of the antagonist muscle during contractions is referred to as autogenic inhibition

21. Neurophysiology Applied
Reciprocal Inhibition
In any synergistic muscle group, a contraction of the agonist causes a reflex relaxation of the antagonist muscle.
An additional passive stretch during the isometric contraction of the agonist pulling the extremity further into the agonist pattern elicits an additional relaxation reflex of the antagonist muscle.
This is called reciprocal inhibition.

22. PNF: Contract-Relax Technique
Start with a Passive Stretch for 15 seconds
Repeat the following pattern3-5 times ending on passive stretch:
Verbal Command “Push” contracting the antagonist muscle being stretched for 10 seconds
Verbal Command “Relax” and move into a deeper passive stretch
Repeat 3-5 times ending on passive stretch for seconds

23. PNF: Hold-Relax Technique
Start with a Passive Stretch for 15 seconds
Repeat the following pattern3-5 times ending on passive stretch:
Verbal Command “Pull” contracting the agonist muscle for 10 seconds
Verbal Command “Relax” and move into a deeper passive stretch for seconds

24. PNF: Slow Reversal-Hold-Relax Technique
Contract-Hold-Relax
Start with a Passive Stretch for 15 seconds
Repeat the following pattern3-5 times ending on passive stretch:
Verbal Command “Push” contracting the antagonist muscle being stretched for 10 seconds
Verbal Command “Pull” contracting the agonist muscle for 10 seconds
Verbal Command “Relax” and move into a deeper passive stretch for seconds

25. Guidelines and Precautions for Stretching
Warm-up
low intensity to high
large gross motor movements to sports specific
multi joint
Why
increase blood flow
increase body temp
increase extensibility
increase respiration/O2 intake
lubricate joints
increase heart rate
remove waste
increase mental acuity
excite nervous system

26. Guidelines and Precautions for Stretching
To increase flexibility, a muscle must be overloaded and stretched beyond its normal ROM but not to the point of pain.
Stretch only to the point of tightness or resistance; NO PAIN!
Increases ROM will be specific to whatever muscle or joint is being stretched.
Be careful when stretching painful joints. Pain is the body’s way of letting you know something is wrong.

27. Guidelines and Precautions for Stretching
Avoid overstretching
Exercise caution when stretching the neck and low back. Exercises that compress the vertebrae and discs can cause damage.
To reduce stress on the low back, stretch in a seated position
Stretch muscles that are tight and inflexible
Strengthen loose muscles

28. Guidelines and Precautions for Stretching
Apply stretches that are appropriate to the person and/or activity.
Breathe normally
Should be done at least 3 times/week for minimal improvement; 5-6 times/week for maximal improvement