Flexibility (Testing and Training)

1. Flexibility (Testing and Training)

2. Outline • Definitions of Flexibility • Warm up vs Stretching • Factors that influence Range Of Motion (ROM) • Physiology and Biomechanics of Flexibility • Assessment of Flexibility • Benefits of Flexibility • Flexibility program variables

3. Definitions of Flexibility • “ability to be bent, pliable” The New Shorter Oxford English Dictionary (1993) • Functional ability of a joint to move through its full range of motion (ROM) (ACSM 2010) • Functional ability - movement without incurring pain or a limit to performance • “The ability of a joint to move through its full range of motion” (Brooks et al. 2000). • There is little agreement about the definition of “normal” flexibility. • Optimum flexibility is hard to assess, and varies with sport. • More ROM is not necessarily better. • Inadequate flexibility can decrease performance of activities of daily living as well as some sports.

4. Further Definitions • Flexibility refers to the extensibility of periarticular tissues to allow normal or physiological motion. • Laxityrefers to the stability of a joint (Saal, 1987). • Excessive joint laxity can be the result of injury or heredity condition. • Hypermobilityrefers to a range of motion in excess of the accepted normal motion in most of the joints (Alter, 1996).

5. Types of Flexibility • Static flexibility: ROM about a joint with no emphasis on speed. • Ballistic flexibility: usually associated with bobbing or bouncing motion. • Dynamic (functional) flexibility: ability to use ROM in the performance of a physical activity.

6. Warm up • Warm up prepares athletes for training or competition • May reduce the risk of injury and improve performance • Increase muscle temperature, core temperature, and blood flow • Impact on performance; • Faster muscle contraction and relaxation • Increased rate of force development • Inc muscle strength and power • Lowers viscosity of muscle • Improved O2 delivery (Bohr effect - temperature) • Increased blood flow to active muscle • Increased rate of metabolic reactions NSCA - Essentials of Strength Training and Conditioning 2008

7. Components of a Warm up • Warm up should be gradually progressive without causing fatigue • General - 5 to 10 minutes low intensity • My be sport specific (jogging / ball dribbling) • Raise HR, ventilation, blood flow, deep muscle temperature and reduce viscosity • Specific - 10 minutes • Dynamic stretching (mobility drills) - sport specific movements (examples near end of lecture) • Progressively increase intensity - sprint drills, jumping • High intensity dynamic exercises may facilitate subsequent performance • Static Stretching in warm up may decrease subsequent performance • Decreased force, power, running speed, reaction and movement time, endurance NSCA - Essentials of Strength Training and Conditioning 2008

8. Factors that Influence ROM • Range of Motion (ROM) is joint specific, and results from a combination of factors; including adequate warm-up • Structure of Joint - (47%) • Determines degree of freedom of movement • Hinge vs ball and socket joint • Rigidity of Ligaments (10%) • Help stabilize and protect joints from excessive motion during dynamic movements • Restrict ROM and offer support at end of ROM • Extensibility of periarticular tissues - muscle and tendon (41%) • Component that can be modified most significantly and influenced by flexibility training • Length of muscle and level of neurological innervation in muscle being stretched

9. Other influences on Flexibility • Nervous system activity • Sudden stretch of a muscle stimulates muscle spindle and reflex contraction • Important for proprioception and controlling muscle length • Slow static stretches, spindle activity increases for about 10 sec then diminishes greatly • This can also help alleviate muscle cramps • Intracapsular structures • articular cartilage and synovial membranes facilitate smoothness of movement while maintaining integrity of joint • Soft tissue • compression of soft tissue by adjacent segments contributes to termination of ROM • Eg obese or very heavy musculature

10. Limits due to Muscle Structure • Contractile Components of Muscle • Sacromere (S) resting length 2.30mm • Maximum extensibility 3.50mm (150%) • Hence increased extensibility occurs by an increase in the # of sarcomeres in series • Improper Muscle Balance • Stretch short muscle (flexibility assessment) • Strengthen weak muscle (strength assessment)

11. Total Length-Tension Curve Text Fig.3-18

12. Limits due to Connective Tissue • Connective tissue surrounds muscle fibers (fascia), and in a major component of tendons and ligaments • Collagen - strong and flexible but resist stretching • Elastin - thin with high degree of elasticity • ability to stretch and recoil • Stress / Strain curves • Fig 54.1 ACSM • Linear - elastic region - will return to original shape • non linear - plastic deformation and repair by fibroblasts • Sustained stretch of 30-90 seconds in necessary to get beyond elastic recoil properties of skeletal muscle and stimulate fiber reorganization • Goal of flexibility training program is to induce gradual deformation of connective tissue - stimulate repair and greater ROM

14. Limits due to Connective Tissue • Aging • Joints become less stable and less mobile • Degradation of collagen, joint surface, and decreased viscosity of synovial fluid • increases collagens diameter and more collagen cross-links • Stiffness and inflexibility common with aging • Sometimes difficult to separate aging from wear and tear to joints • Flexibility training can induce remarkable improvements in aged population if no permanent damage to joint structure has occurred

15. Assessment of Flexibility • Measurement made visually or with special instrumentation • Utilize active or passive movement of subject • Precision in assessment techniques enhances both accuracy and reliability • Proper identification of landmarks • Consistency in the inclusion or exclusion of a warm-up is important for reliability • Starting position and body position for measurements • Visual assessment (qualitative) - inaccurate for both spinal and extremity evaluation • but useful for fitness screening, group evaluation and field testing - we will do several visual assessments • Degree of completion of assessment in standard position - see lab manual • Eg - Finger tips touching (or not) with combined bilateral rotation of shoulders and elbow flexion

16. Quantitative Assessment of Flexibility • Measurement Devices • Indirect - linear - sit and reach apparatus, anthropometer, tape measure • Direct - ROM in degrees - Goniometer / Leighton Flexometer • Goniometer is inexpensive and portable • Kin 142 no longer uses Flexometer • We will perform one measurement with Flexometer for familiarity and one with Goniometer for review • Dynamic Flexibility can be measured with stop motion video with reflective markers on bony landmarks • Similar to motion capture for video games and animation

18. Quantitative Measurements • Eg. Sit-reach (modified by Hoeger) - accounts for influence of length of body segments necessary when doing indirect measures • First measure taken with back touching wall • Second measurement with truck flexion • Difference provides data for comparison

19. Benefits of Flexibility Training • Increased physical performance • Decreased risk of injury (but not due to inclusion as part of a warm-up) • Increased blood supply and nutrients to joint structure • Increased quality and quantity of joint synovial fluid • Increased muscular coordination • Improved muscular balance, posture and postural awareness • Decreased muscle viscosity, causing contractions to be easier and smoother

20. Benefits of Flexibility (cont) • Reduced muscular soreness • Promotion of relaxation (reduced muscular tension and cramps) • Decreased risk of low back pain • Reduced stress and tension • Increased enjoyment • Promotes self-discipline • Unification of body, mind and spirit (e.g. Yoga) • Improves ease and efficiency of movement • Increased Range of Motion • Improves skill in sport

21. Reasons why stretching before exercise may not prevent injury • An increase in muscle compliance may cause tissues to rupture more easily. • Stretching before exercise will have no effect for activities where excessive muscle length is not an issue. • Stretching will not affect muscle compliance during eccentric activity, where most strains are believed to occur. • Stretching can produce damage at the cytoskeleton level. • Stretching appears to mask muscle pain in humans.

22. Who should not Stretch? • Everyone can learn to stretch • Caution for people who have naturally excessive ROM - should not stretch in extremes of ROM as joint stability should be maintained • Recent push to certify Yoga instructors locally, reduce incidence of injury to clients • Pregnancy - hormone relaxant - softens ligaments and connective tissue especially in pelvis - excessive stretching can lead to hypermobility of low back • Table 54.2, 54.3 ACSM

25. Flexibility Training Program • Athletes should stretch following practice or as a separate session (after sufficient warm up) • Muscle is warm, collagen is elastic which allow greater stretch • May decrease muscle soreness • Training Program • A planned, deliberate, and regular program of exercises that can permanently and progressively increase the useable range of motion of a joint or set of joints over a period of time (Corbin and Noble, 1980). • Stretching recommended after sitting or standing for long periods - helps prevents discomfort (not enough to count as a training program)

26. Duration and Frequency • Variable opinions • Duration • Beaulieu - 10-15 secs - progress to 45-60 secs over 4-5 weeks • Anderson - 10-30 sec easy; 10-30 sec developmental stretch • ACSM 10-30 seconds - but emphasize that connective tissue deformation and neuro-inhibitory effects require 30-90 seconds to effect tissue change and relaxation • Yoga - variable - 45-90 seconds • Frequency • Beaulieu - 2-3 times / week • Yoga - daily for 30-45 minutes - relaxation

28. Controversy • Optimum flexibility • sport specific? • Types of stretching • Safety vs effectiveness • Static vs dynamic stretching and performance • Dangerous stretches • Cautions in some guides, recommended in others? • Stretching during warm-up and cool-down • Is it enough to effect changes in flexibility? • Does it have an impact on injury or muscle soreness?

29. Advantages Development of dynamic flexibility Effectiveness Team camaraderie Interest Disadvantages Inadequate tissue adaptation Soreness and injury Initiation of stretch reflex Inadequate neurological adaptation Disadvantages outweigh advantages Ballistic Stretching

30. Advantages Historical preference Effective and optimal Decrease possibility of exceeding normal ROM Less energy Less muscle soreness Recommended as advantages outweigh disadvantages - especially for general population Disadvantages Boring May overly dominate routine due to time needed Allows body to cool during warm up Principle of specificity - effectiveness for improving dynamic flexibility? Increase chance of injury by reducing amplitude of stretch reflex? Static Stretching

31. Advantages Focused on sport specific movement Development of dynamic flexibility Increases temperature Muscle is active Team camaraderie Interest Avoids bouncing and is more controlled than ballistic stretching Disadvantages Inadequate tissue adaptation (ROM) Soreness after first sessions Inadequate neurological adaptation advantages outweigh disadvantages Dynamic Stretching(mobility drills) NSCA - Essentials of Strength Training and Conditioning 2008

32. Preferred method of stretching during warm up Actively moving joint through ROM required for sport Observe sport specific movement patterns, and select exercises that mimic those patterns Build progressively through each exercise Speed and ROM Perform under control ROM often less than what could be achieved with ballistic type movements Do not accelerate limb to end of ROM Dynamic Stretching(mobility drills) NSCA - Essentials of Strength Training and Conditioning 2008

33. Dynamic Stretching • STRAIGHT-LEG MARCH • (for the hamstrings and gluteus muscles) • Kick one leg straight out in front of you, with your toes flexed toward the sky. Reach your opposite arm to the upturned toes. Drop the leg and repeat with the opposite limbs. Continue the sequence for at least six or seven repetitions.

34. Dynamic Stretching • SCORPION • (for the lower back, hip flexors and gluteus muscles) • Lie on your stomach, with your arms outstretched and your feet flexed so that only your toes are touching the ground. Kick your right foot toward your left arm, then kick your leftfoot toward your right arm. Since this is an advanced exercise, begin slowly, and repeat up to 12 times.

35. Dynamic Stretching • HANDWALKS • (for the shoulders, core muscles, and hamstrings) • Stand straight, with your legs together. Bend over until both hands are flat on the ground. “Walk” with your hands forward until your back is almost extended. Keeping your legs straight, inch your feet toward your hands, then walk your hands forward again. Repeat five or six times. G.R.

36. NSCA - Essentials of Strength Training and Conditioning 2008

38. Additional Classifications • Passive stretching - partner or stretching machine provides external force • Active Stretching - person stretching provides force • Proprioceptive Neuromuscular Facilitation • contract muscle prior to stretch- 6 sec contraction; 10-30 sec stretch (Contract - Relax) • Autogenic inhibition • Golgi tendon organ and muscle spindle relaxation • Some also coincide stretch with contraction of agonist (ms opposite one being stretched) (Contract - Relax (Agonist Contract)) • Reciprocal inhibition • Increased range of motion over static stretching • More motivation required - beneficial to have knowledgeable partner • More time • Increase pain and soreness and injury?

39. NSCA - Essentials of Strength Training and Conditioning 2008