Training for Flexibility and ROM (2024) PDF

FLEXIBILITY: BACKGROUND/IMPORTANCE TRAINING TO IMPROVE FLEXIBILITY SEE CHAPTER 5 Flexibility: Importance & Benefits “Although flexibility may not impact health indicators as shown with aerobic or muscular fitness, stretching exercises should be considered as a valuable component of...

FLEXIBILITY: BACKGROUND/IMPORTANCE TRAINING TO IMPROVE FLEXIBILITY SEE CHAPTER 5 Flexibility: Importance & Benefits “Although flexibility may not impact health indicators as shown with aerobic or muscular fitness, stretching exercises should be considered as a valuable component of a complete exercise program” – ACSM Why? (next slide) 1  Flexibility: Importance & Benefits For performing activities of daily living To improve Muscle/Joint Health –  muscle stiffness and tension. Which then … es ROM joints es joint stress caused by muscle imbalance - e.g., Repetitive Use – Shown to improve postural stability and balance  muscle stiffness due to loss of elasticity - e.g., as can occur with aging and inactivity Increase muscle blood flow. However, – Acute and long-term vascular adaptations associated with stretching remain inconclusive (e.g., changes in blood pressure, endothelial function) Both acute and chronic stretching considered to be effective for pain relief/management. Flexibility: Importance & Benefits The associations or relationships between stretching and the following variables is questionable (i.e., research is conflicting or sparse): – Improving Athletic Performance - ? May depend on type of performance – Prevention of Low Back Pain - ? – Reducing DOMS - ? However - chronic stretching (i.e., 3 to 6 weeks) prior to the exercise may reduce severity of DOMS – Reducing chance of muscle injury - ? Note: hyper-flexibility can increase chance of injury. Note: using stretching exercises for the “acute” purpose of improving exercise performance or reducing muscle soreness is not recommended Source: David G. Behm, Anthony D. Kay, Gabriel S. Trajano, Shahab Alizadeh, Anthony J. Blazevich; Effects of Acute and Chronic Stretching on Pain Control. Journal of Clinical Exercise Physiology 1 December 2021; 10 (4): 150–159. doi: https://doi.org/10.31189/2165-6193-10.4.150 2 Flexibility: Importance & Benefits Improving Flexibility: Background Flexibility is trainable. Meaning … – Joint ROM and flexibility can be improved by engaging in flexibility exercises that are specific to the joint of interest – Joint ROM has shown chronic improvement after about 3–4 weeks of regular stretching 2-3 times per week – Also – Joint ROM can be improved immediately (acutely) after performing stretching exercises How does joint ROM & flexibility increase with stretching? – Decreases in neural inhibition (e.g., muscle spindle, next slide) The notion that unilateral stretching of the quadriceps can improve ROM of the opposite quadriceps speaks to neural involvement – Decreases in musculotendinous unit stiffness, and/or – Greater tolerance to the stretch 3  Improving Flexibility: Background Muscle spindle is “stretched” with increases in muscle length This triggers the stretch reflex – which attempts to resist the change in muscle length – For a reminder on how the stretch reflex works, see: https://www.youtube.com/watch?v=qsdU6nhgq28 The more sudden the change in muscle length, the stronger the muscle contraction (i.e., the stronger the reflex). As you hold the muscle in a stretched position, the muscle spindle habituates and reduces its signaling (causing relaxation) You can train your stretch receptors to allow greater lengthening of the muscles. Improving Flexibility: Types of Stretching How to improve joint ROM & flexibility? Types of Stretching (See Box 5.5) – Static Stretching Involves slowly stretching a muscle/tendon group and holding the position for a period of time (i.e., 10–30 s). Static stretches can be active or passive. – Passive (Assisted) Static Stretching involves assuming a position while holding a limb or other part of the body with or without the assistance of a partner or device (such as elastic bands – Active Static Stretching involves holding the stretched position using the strength of the agonist muscle 4 Improving Flexibility: Types of Stretching How to improve joint ROM & flexibility? Types of Stretching (Box 5.5) – Proprioceptive Neuromuscular Facilitation (PNF) Stretching Most commonly involves an isometric or concentric contraction of the selected muscle/tendon group followed by a static stretching of the same group (i.e., hold-relax, contract-relax). There are several variations – These involve different sequences of stretching and contracting movements Improving Flexibility: Types of Stretching How to improve joint ROM & flexibility? Types of Stretching (Box 5.5, cont.) – Dynamic Stretching Dynamic or slow movement stretching – Involves a gradual and controlled transition from one body position to another and a progressive increase in reach and range of motion as the movement is repeated several times. Ballistic Stretching – Uses the momentum of the moving body segment to produce the stretch – i.e., “forceful bouncing” 5  Static Stretching A muscle is: – Slowly moved into a position at end the ROM – This position is then held 10-30 sec/stretch Longer for older adults The end of the ROM should be the point where tension is felt – Feeling tightness or slight discomfort – But not pain Why slowly? – To reduce stretch reflex Can be - Active or passive (assisted, outside force) Safe & Simple Effective at increasing ROM – Note: holding a static stretch for over 60–90 s without additional dynamic activities will acutely lead to performance decrements Active Static Stretching The target muscle is stretched by contraction of the opposing muscle. NM Rationale? – Reciprocal Inhibition: – Relaxation of stretched muscle Not as effective 6  PNF Stretching: Hold-Relax (H-R) Technique Target muscle is passively moved and held into position of stretch Then, static/isometric contraction of  the target muscle 20-75% of MVIC Duration: 3-6 sec  Relax & target muscle is then  passively moved into a greater position of stretch Duration: 10-30 sec H-R Technique for stretching H-R probably the most common PNF hamstrings technique Effective at increasing ROM Link: https://humankinetics.me/2018/04/25/what-is-pnf-stretching/ PNF Stretching: Contract-Relax (CR) Technique Target muscle is passively moved into position of stretch  Position is held Then, concentric contraction of the  target muscle 20-75% of MVIC  Duration: 3-6 sec Target muscle is then passively moved into a >er position of stretch CR Technique for stretching hamstrings Duration: 10-30 sec 7  PNF Stretching: Hold-Relax Agonist Contract (HRAC) Technique Target muscle is passively moved into position of stretch Then, static (or concentric) contraction of the target  muscle Target muscle is then passively and actively moved into a greater position of stretch  CRAC Technique for stretching chest PNF Stretching: The Physiology Why contract target muscle before stretching? – Better relaxation of stretched muscle during stretch Autogenic Inhibition via Golgi Tendon Organ (traditional theory) Changes in viscoelastic properties, Better stretch tolerance HRAC Technique – Also involves Reciprocal Inhibition PNF methods are effective (see next 2 slides) Often Require assistance (e.g., partner, device) More time consuming Caution with older adults 8 9  Dynamic Stretching Involves a gradual transition from one body position to another and a progressive increase in reach and range of motion as the movement is repeated several times. – i.e., Actively moving a limb through its full ROM to the end ranges and repeating several times. – There is “No Hold” – Active – Examples: Arm Circles, Lunge Effective at increasing ROM Also … it is encouraged prior to any exercise bout and may also be used to improve performance (i.e., ergogenic). – i.e., include as part of warm-up – Ergogenic effect – especially for SSC movements Dynamic Stretching: Ballistic Uses the momentum of the moving body segment to produce the stretch. So … Involves forceful bouncing or ball-like movements that quickly exaggerate the joint’s ROM without holding the position. Although effective at increasing ROM … Generally reserved for adults who engage in activities that involve ballistic movements 10  Stretching: FITT Recommendations Mode – To improve ROM, it is reasonable to recommend any type of stretching – Static stretching is most common Intensity – Point of feeling tightness or slight discomfort – Slowly apply the stretch Stretch duration (of a single stretch repetition) – 10 – 30 sec/stretch repetition – Older adults: 30-60 sec/stretch repetition – If using PNF (H-R or C-R) Contraction: 3–6 sec @ 20-75% of max effort (MVIC) Stretching: FITT Recommendations Volume – Exercise number To target the major muscle tendon units of the shoulder girdle, chest, neck, trunk, lower back, hips, posterior and anterior legs, and ankles – Duration (i.e., time under stretch): A total of 90 s of discontinuous flexibility exercise per joint is recommended 2-4 repetitions of each exercise to accumulate a total of 90 s Frequency – ≥ 2–3 d ∙ wk−1 with daily being most effective Other notes: – Flexibility exercises are most effective when the muscles are warm – Stretching should be performed on their own – i.e., as part of a specific program to increase ROM 11  Stretching: FITT Recommendations Other notes (cont.) Stretching (static and PNF, at least) may acutely reduce strength and power – >60 s of stretching may have a deleterious effect on muscle/exercise performance (e.g., sprinting, maximal effort contractions, etc. Thus, they should be avoided prior to an exercise bout – see next slides 12 13