Restoring Range of Motion and Improving Flexibility Importance

Restoring Range of Motion and Improving Flexibility

Importance of Flexibility l Important Goal: Restore or improve to normal pre-injury range of motion l With injury there is generally some degree of lost range of motion Due to pain, swelling, muscle guarding, &/or inactivity resulting in tissue shortening l Need to encourage stretching exercises l l Restricted range of motion can impact performance & result in uncoordinated motion l Essential for successful physical performance & injury prevention

Flexibility l Ability of neuromuscular system to allow for efficient movement of a joint or series of joint through a full, non-restricted pain free range of motion

Anatomic Factors Impacting Flexibility l Muscles l l Connective Tissue l l Increasing flexibility relies on the elastic properties of muscle l Length can be changed over time Ligaments & joint capsules, while possessing some elastic properties, can lose their elasticity during periods of disuse & immobilization Bony Structures Can limit end point range l Bony prominences can also stop movements at normal end points in the range l l Fat Can act as a wedge between lever arms l Restricts movement wherever it is found l

l Skin l Injury or surgical procedure may alter skin – variable in elasticity l l Skin adheres to underlying tissue Neural tissue Develops tightness as a result of compression, chronic repetitive microtrauma, muscle imbalances, joint dysfunction or morphological adaptations due to posture l Could stimulate nociceptors & pain l Cause muscle guarding & spasm to protect irritated neural structures l Neural fibrosis ultimately results causing decreased elasticity & restricted motion l l Except for bone structure, age & gender all other flexibility limiting factors can be modified & altered to increase range of motion

Soft Tissue Properties that Affect Immobilization & Elongation l Responses stretching that affect soft tissue during l Velocity, intensity, frequency & duration of stretch force l Temperature of tissues l Elasticity – ability of soft tissue to return to its resting length after passive stretch l Plasticity – tendency of soft tissue to assume a new & greater length after stretch force has been removed

Soft Tissue Properties that Affect Immobilization & Elongation l Contractile tissue: gives muscle characteristics of contractility & irritability l Noncontractile tissue: has same properties as all CT, including ability to resist deforming forces as well as viscoelasticity l CT structures of muscle-tendon unit l Epimysium – enveloping fascial sheath l Perimysium – encases bundles of fasciculi l Endomysium – innermost layer that separates individual m. fibers & myofibrils

CT Structures of Muscle-tendon Unit

Muscle Anatomy l l Made up of many muscle fibers that lie parallel with one another Single fiber – made up of many myofibrils Myofibrils - composed of sarcomeres Sarcomere – contractile unit of the myofibril Gives muscle ability to contract & relax l Composed of overlapping myofilaments of Actin & Myosin (form cross-bridges) l l Motor unit stimulated = m. contraction -actin-myosin filaments slide together & the muscle actively shortens l Muscle relaxes = cross-bridges slide apart slightly & the muscle returns to its resting length

Muscle Anatomy

Muscle Structure

Myofilament l l Interlocking Mesh Structure A myofilament shows several distinct bands Each band has been given a special letter The lightest (least electron dense) band is the “I band” Consists primarily of actin l In the center of the “I band” is the “Z-line”, an electron dense line l l The wide, dark band is the “A band” Consists primarily of myosin l In the middle of the “A band” is the “M line”, another dense line l

Myofilament Sliding

Noncontractile Tissue l Made up of: l l Collagen – resist tensile deformation & are responsible for strength & stiffness of tissue, elongates quickly under light loads Elastin - extensibility Reticulin fibers – bulk Ground substance – proteoglycans (PGs) & glycoproteins; PGs hydrate matrix, stabilize collagen network, resist compressive forces; l Glycoproteins provide linkage between matrix components & between cells & matrix opponents l l Mechanical behavior is determined by proportion of collagen & elastin fibers & structural orientation of the fibers High collagen, low PGs – resist high tensile loads l High collagen content tissue = greater stability (tendons) l

Active & Passive Range of Motion l Active range of motion (AROM) l l Dynamic flexibility Joint movement via muscle contraction Ability to move a joint with little resistance Passive range of motion (PROM) l l l Static flexibility Motion of joint to end points without muscle contraction Critical in injury prevention l l l Muscles can be forced to stretch beyond “normal” limits Without elasticity it is likely that the musculotendinous unit will be injured During athletic activity l l Must be able to move through unrestricted range Must have elasticity for additional stretch encountered during activity

Measuring Range of Motion Essential to assess improvement during rehabilitation l Goniometer l Utilizes alignment of two arms parallel to longitudinal axis of two segments involved in motion l Relatively accurate tool l l Ensures accuracy standardize techniques & methods of recording AROM & PROM

Agonist vs. Antagonist Muscles Joints are capable of multiple movements l Example: l l Quadriceps will extend knee with contraction l Quads (muscle producing movement) = agonist l Hamstrings will stretch during knee extension l Hamstrings undergoing stretch = antagonist l Agonist & antagonist work together to produce smooth coordinated movements l Muscles that work together function synergistically l What is another pair of agonist/antagonist muscles?

Stretching Techniques l Ballistic l l Static stretching l l Stretch to point of discomfort & holding at that point for period of time Proprioceptive Neuromuscular Facilitation (PNF) l l Bouncing movement in which repetitive contractions of agonist work to stretch antagonist muscle Involves alternating contractions & stretches Myofascial & neural tissue stretching l Enhances neuromuscular system’s ability to control movement

Ballistic Stretching l Need to be careful when performing this stretch l Possible soreness due to uncontrolled forces within muscle created by bouncing l May result in tissue damage l Should be incorporated into a program to allow body to adapt & reduce likelihood of injury l Incorporate into later stages of rehabilitation

Static Stretching l Passively stretching given antagonist l 6 -8 second hold in maximal position of stretch l Go to point of discomfort & back off slightly l Hold for 15 -30 seconds (do this 3 -4 times) l Can be accomplished utilizing agonist l Controlled movement, less chance of injury

Proprioceptive Neuromuscular Facilitation l Three techniques that combine alternating isometric or isotonic contractions & relaxation of both agonist & antagonists Slow-reversal-hold-relax l Contract-relax l Hold-relax l l Hold Relax (HR) Isometric contraction of antagonist followed by concentric contraction of agonist with light pressure l Facilitates stretch of antagonist l Effective with muscle tension on one side of joint l

l Contract Relax (CR) l l l Moves body passively into agonist pattern Athlete instructed to contract antagonist isotonically against resistance Athlete then relaxes & allow athletic trainer to push body further (passively) into agonist pattern Utilized when flexibility is limited due to muscle tightness Slow Reversal-Hold-Relax (SRHR) l Isotonic contraction of agonist l Follow with isometric contraction of antagonist l During relax phase antagonist is relaxed while agonist contracts in agonist pattern l Results in stretch of antagonist l Useful to stretch antagonist

Comparing Stretching Techniques Ballistic stretching is recommended for athletes engaged in dynamic activity l Static stretching most widely used l l l Safe & effective PNF techniques Capable of producing dramatic increases in ROM l Limitation – partner is required l l Maintaining flexibility Can decrease considerable after only 2 weeks l Should be engaged in at least once per week l

Specific Stretching Exercises

Stretching Neural Structures Requires differentiation between musculotendinous & neural tightness l Assess movements that create tension in neural structures l May cause numbness & tingling l Straight-leg raise example l

Myofascial Release Stretching l Techniques used to relieve abnormally tight fascia l Myofascial restrictions are unpredictable & may occur in different planes & directions Requires specialized training & in depth understanding of fascial system l Fascia l Connective tissue that runs throughout the body & establishes interconnectedness of body l If altered or injured can result in localized response at focal point of injury or away from injury site l Responds to gentle pressure l

l Sometimes called: Soft-tissue Mobilization l Treatment Localize restriction Considerably more subjective component & relies heavily on clinician’s experience l Focuses on large treatment area l Work superficial to deep l Joint mobilizations may follow l Tissue stretching & elongation as well as strengthening should follow l Postural re-training may also be required l Dramatic results may occur l Treatment should be done at least 3 times per week l Perform manually or via foam roller l l

Neurophysiological Basis of Stretching Stretch Reflex l Muscle is placed on stretch – muscle spindle l Muscle spindles fire relaying info. to spinal cord l Spinal cord relays message to golgi tendon & increases tension l After 6 seconds, golgi tendon organ (GTO) relays signal for muscle tension to decrease l Cause reflex relaxation l Prevents injury - protective mechanism l Ballistic stretching does not allow this overriding response by GTO

l With static stretching GTO’s are able to override impulses from muscle spindle following initial reflex resistance l Allows injury muscle to remain stretched without l PNF benefits greatly from these principles l With slow-reversal hold technique, maximal contraction of muscle stimulates GTO reflex relaxation before stretch applied

l Autogenic inhibition l Relaxation of antagonist during contraction l During relaxation phase, antagonist is placed under stretch but assisted by agonist contraction to pull further into stretch l GTO is protective mechanism that inhibits tension in the muscle l Reciprocal inhibition l Isotonic contraction of an agonist muscle elicits a reflex relaxation of antagonist muscle group (protect against injury)

Effect of Stretching on Physical & Mechanical Properties of Muscle Physical lengthening of muscle occurs due to reflex relaxation l Contractile & non-contractile elements of muscle dictate capability of deformation & recovery l Both resist deformation l Deformation is dependent on degree of stretch & velocity l l Non-contractile – limit degree l Contractile – limit velocity l Greater stretch = more non-contractile components contribute

l Stretches sustained long enough (autogenic inhibition) result in viscoelastic & plastic changes in collagen & elastin l Viscoelastic changes allow slow deformation & imperfect recovery (not permanent) l Plastic changes result in permanent changes in length l Greater velocity = greater chance for exceeding tissue capacity (viscoelastic & plastic)

Effects of Stretching On Kinetic Chain l Joint hypomobility causes: Faulty posture l Muscular imbalance l Abnormal neuromuscular control l l Alteration in arthrokinematics Change in muscle tension to reduce translation l Alters degrees of tension & activation in synergist, stabilizers & neutralizers l Compensatory response l

Muscle Tightness & Hypertonicity l l l Impact on length-tension relationships Alters force couples & arthrokinematics Impacts normal force couple relationships & creates kinetic chain reaction Impacts synergistic function of kinetic chain Causes abnormal joint & tissue stresses, neural compromise & vascular/lymphatic stasis Alters recruitment strategies & stabilization l l l Alters neuromuscular efficiency impacting activation/firing sequence Additionally altered joint function & stress response Can causes reciprocal inhibition Increases muscle spindle activity May impart inhibitory response (decreased neuromuscular control) Result = synergistic dominance – synergist compensatory action for weak & inhibited muscle

Importance of Warm-up Prior to Stretching l l l l Intramuscular temperature should be increased prior to stretching Positive effect on ability of collagen & elastin to deform Enhances reflexive relaxation associated with golgi tendon organs Optimal temperature 39 o. C/103 o. F To increase = low intensity, warm-up type exercise or modalities Exercise should be primary means of warm-up Environment - Heat vs. Cold

Flexibility vs. Strength Co-exist l Muscle bound l Negative connotation l Loss of motion l Encourage full pain free movements during rehabilitation l Strength training will provide individual with ability to develop dynamic flexibility through full range of motion l Develop more powerful & coordinated movements l

Guidelines & Precautions for Stretching Warm-up l Overload or stretch beyond normal range l l l l Not to point of pain l Stretch to point of resistance Increases in range will be specific to muscle being stretched Use caution when stretching around painful joints Avoid overstretching ligaments & capsules Exercise caution with low back & neck stretches Stretch from seated position to reduce stress on back l l l Continue normal breathing while stretching For improvements in ROM, utilize static & PNF stretching techniques Ballistic stretching should be used by those who possess flexibility & are accustomed to it Ballistic stretching should follow period of static stretching Stretching should be performed a minimum of 3 times per week For maximum gains stretching 5 -6 times per week is ideal