10/2/11


Stretching Deanna Rogers PT, CCRP Good Life Physical Therapy for Animals

Outline Flexibility Benefits of stretching   Effects of stretching   Anatomy, physiology and neurology of stretching   End feels   Precautions with stretching   How to stretch    

Flexibility and Stretching Flexibility is the ability of the tissue to relax and respond to elongation forces1   Stretching addresses the flexibility of muscles, periarticular tissues, tendons, ligaments and skin   Stretching/flexibility deal with the intrinsic properties of the muscles and joints to go through an optimal range of motion2  

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Benefits of Stretching          

Increase range of motion and promote fluid movement Improve flexibility by elongating the tissue Help relax muscles and reduce soreness3 Improve circulation and reduce stress (Mayo Clinic) National Arthritis Foundation   Reduce joint pain and stiffness   Increase strength   Reduce inflammation

Effects of Stretching  

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With regular long term stretching there are changes in the surrounding connective tissue and an increase the elasticity of the mm-tendon unit”2 There are also remodeling in the muscle where there is an addition of sarcomeres to the muscle (DeDeyne 2001)2 and changes the concentration and arrangement of the collagen within the muscle (Goldspink et al 1974, Williams and Goldspink 1978, Witzman et al 1982) Passive stretching may reduce mm atrophy due to changes in the length of the mm fibers4,5,6  

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Study on mice – intermittent mm stretching helped to prevent atrophy and loss of sarcomeres of immobilized tissues with varying durations in minutes per day of stretching Decreased intramuscular connective tissue that develop during immobilization on those mice that received stretching

Effects of Stretching  

Stretch tolerance – this is the theory that stretching may elicit an analgesic effect resulting in increased pain threshold without actual changes in the muscle stiffness (Magnusson 1988, Shrier 1999, Law et al 2009)7  

May with neurological problems or chronic musculoskeletal pain get continued muscle stiffness but improved joint ROM

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Muscle Anatomy & Physiology  

Muscle (mm) is made of viscous (sarcoplasm), elastic (muscle filaments actin and myosin) and nonelastic (connective tissue) fibers   Viscoelastic

property: The mm’s passive resistance to elongation of a stretch and the tension decay associated with it is the stress relaxation   Viscoelastic property: With sustained holding of a stretch the mm will gradually elongate, known as creep.   Elastic property: the tissues act like a spring that lengthen and returns to their natural resting length and in direct proportion to applied and released stresses2

Muscle Anatomy

Tendon Anatomy & Physiology • 

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Tendons are made primarily of collagen fibers lined up parallel to one another so they are regular dense fibrous tissue. When a stretch is applied, the collagen fibers straighten As the tension is held, the tissue remains elastic and then the collagen returns to its normal resting position after the stretch is released (elastic property) If the tension is prolonged, one can damage the bonds between the collagen fibrils and fibers

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Tendon Anatomy

Muscle and Tendon Units

Muscle Spindle Anatomy  

Muscle Spindles   Infrafusal

fibers are specially differentiated active mm fibers which are connected to mm tendons in parallel with the extrafusal fiber fibers make up the bulk of the mm mass   Each spindle consists of 2-12 intrafusals contained in a connective tissue sheath that run parallel to the extrafusal fibers but connect with them at the end   Muscle spindles signal mm length continuously as part of the proprioceptive system – rate of discharge changes with the change of length   Extrafusal

  Primary afferents, Ia, sense rate of change and length   Secondary afferents, II, sense stretch only   Alpha motor neurons are the efferents with the extrafusal muscle   Gamma motor neurons are the efferents with the intrafusal muscle

to maintain muscle spindle sensitivity

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Muscle Spindles and Golgi Tendon Organs • 

The receptors called proprioceptors or mechanoreceptors of the muscle spindle monitors the velocity and degree of the muscle stretch – 

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When a muscle is stretched rapidly, the mm spindle contracts which stimulates the primary afferent fibers and results in increased mm tension – monosynaptic stretch response there is less stimulation of the Ia and II spindle afferent fibers when the stretch is slow

The proprioceptors or mechanoreceptors of the Golgi tendon organ detects the mm tension during a mm contraction, signaling the force of the contraction and inhibits contraction of the mm if there is too much force

Muscle Spindle Neurology

Muscle Spindle & GTO Neurology

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Golgi Tendon Organ Golgi tendon organs are made of sensory dendrites interwoven in the collagen fibrils   Ib afferents are stimulated by the force of the contraction   Through the interaction of an inhibitory interneuron, get the agonist muscle to relax to avoid too much force in a contraction   May also get excitation of the antagonist muscle through reciprocal inhibition  

Golgi Tendon Organ (GTO)

GTO Neurology

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Muscle Spindle & GTO Neurology

Neuromodulation of Stretching Modulation of reflexes  Inhibition of agonist due to activation of golgi tendon organ so the stretching muscle relaxes  May also get excitation of antagonist by the golgi tendon organ  Desensitization of stretch reflex due to activation of muscle spindles by holding for 15-30 seconds – spindle reduces its’ opposing signaling2

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Tissue Involvement with Hypomobility • 

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With tightness there may be shortening of the muscle belly itself There can also be restrictions in the skin, especially around scars Contractures are where there is shortening of muscles and tissue around joint that then limit ROM1 –  Myostatic contractures have a musculotendinous junction that is shortened –  Scar tissue adhesions which can progress to fibrotic adhesions (like a tie down) –  Pseudomyostatic contracture where the muscle is hypertonic and in a chronic state of contraction

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End Feels   End

feel is the quality of resistance and sensation at extremes of restricted movements or pain8,9.

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sensations of movement barriers can be perceived according to the tissues limiting motion, the anatomical region, and pathological change.  Cyriax, Kaltenborn and Paris describe a number of characteristic end-feels

  Done

passively, gently and with overpressure at end range – if there is pain at the end range, test with extreme caution10

  Intrarater

reliability good but interrater reliability is poor10

Capsular vs Noncapsular Patterns   Capsular

patterns which indicate hypomobility of the entire joint capsule and vary for each joint. Typically accompany degenerative changes, arthritis, prolonged immobilization or acute joint trauma with effusion. Capsular patterns are more empirical data than research but basically each joint can have varying degrees of restrictions in certain motions8

  Noncapsular

patterns typically occur with intra-atricular mechanical blocks or extra-articular lesions

Types of End Feels8-11 Bony end feel - hard and often abrupt (elbow extension & should be painless). When accompanying a restriction it can suggest hypertrophic bony changes like those of DJD or possible malunion of bony segments following healing of a fracture   Capsular end feel – firm and leathery (shoulder ext rotational)   Soft or Boggy – stiffness occurring early in the range and increasing through the range often in a capsular pattern (acute inflammation, synovitis, soft tissue swelling)   Hard – tight resistance with a thick quality to it and definite stopping point after a smooth, friction free movement (chronic inflammation, scar tissue or shortened connective tissue, frozen shoulder)   Muscular or tissue stretch end feel – firm and rubbery/springy and less abrupt than capsular with a more subtle stopping point - often has an elastic resistance quality to it towards the end of the range (SLR, MCP extension, knee extension)  

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Types of End Feels  

Soft end feel or mushy which is often tissue approximation – can be due to mm hypertrophy or tumors (elbow or knee flexion)

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Muscle spasm end feel – movement stopped fairly abruptly with some rebound due to mm contracting reflexively. Can be early in the range so called an “early muscle spasm” or late in the range so called “late muscle spasm”. It’s often painful. Can be accompanied by capsular patterns of restrictions such as DJD with osteophyte formation, acute inflammation, or instability

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Springy rebound end feel – occurs unexpectedly in the range and is springy. Usually indicates internal derangement end feel and often is in a noncapsular pattern (meniscal tear)

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Empty end feel - the mms don’t contract to prevent the movement as that would cause compression of tissue but movement stops at the insistence of pt due to pain (acute bursitis)

Types of Stretching  

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Static stretching – slow elongation of the tissue, holding for a period of time, then returning to resting length Dynamic stretching – slow cyclical elongating, holding and stretching doing exaggerated movements that are sport specific Ballistic stretching – repetitive bouncing motion where the tendons are rapidly stretched and immediately relaxed Proprioceptive neuromuscular facilitation – alternating activation of the shortened muscle with passive elongation developed by Dr.Herman Kabat in the 1950s Resistance stretching – the targeted muscle is taken through resistance while doing eccentric and concentric contractions2

Precautions with Stretching  

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Overstretching – can result in poor soft tissue support so the joint may loose some stability and therefore result in injury1 The muscle will show its greatest resistance to a stretch if the stretch is done rapidly so advised to do stretch slowly to avoid eliciting the stretch reflex (Chambers 2004)2 Be cautious with older patients or those tissue exposed to chronic tightness as the collagen becomes less elastic, more dense and less stretch is needed before plastic deformation. Some studies show this can be minimized with stretching (Basey, E. J et al internet)2 Older patients will have increased mm stiffness and lower stretch tolerance

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Precautions with Stretching Do not do on cooled tissues - heated tissues can result in needing lower loads with significantly longer elongation benefits. Knight and colleagues (2001) showed benefit with stretching after active exercises, superficial heat, or ultrasound with the tissue having the deep heat of the ultrasound showing the most active and passive ROM improvements2   Can get improvements in range of motion even with 10-30 seconds of massage to musculotendinous unit (Huang et al 2010)12  

How to Stretch  

Frequency May need to be 2-3 times a day to 3x/week depending upon the pt’s needs

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Duration

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Intensity

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Hold 15-30 seconds for2-4 repetitions Pt should be able to relax, should not be painful and can try to gently increase range upon pt’s exhalation

How to Stretch…. American College of Sports Medicine recommends 15-30 second holds at 2-4 reps (2006)   Longer durations and more repetitions have not been found to produce significant benefits – more is just more   Slow rates of stretching permit greater stress relaxation and creep than faster rates   Slow rates of elongation limit stimulation of the stretch reflex  

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How to Stretch ….  

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Stretching 3-5 days per week may result in measureable increases in flexibility Need rest periods between intense stretching sessions to allow adaptive remodeling Consider cooling tissues in elongated position if you feel your results are not long lasting Can take 2-3 weeks before seeing a difference Stretching should not be painful. Stretch to the point of the limitation of the movement – not to pain. This is the “endpoint” of the stretch

Key Components to Stretching •  •  • 

Make sure you are in a comfortable position Allow the patient time to relax in their position Support joint with both hands on your patient –  – 

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Stabilize the bone proximal to the joint Stabilize the bone distal to the joint

Slowly move the distal bone and with no signs of pain Go to the point of resistance (endpoint) and then back off just a little and HOLD HOLD x 15-30 seconds Slowly release Repeat x 2-4 repetitions Two joint stretches – may need less force

Thank You ….

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