Corrective Exercise Science

NASM Essentials of Corrective Exercise Science Study Guide CHAPTER 1: The Rationale for Corrective Exercise  Rationale for Corrective Exercise -Musculoskeletal pain is more common now that it was 40 years ago decreased activity leads to muscular dysfunction and, ultimately, injury.     Food &Ankle Injuries  Plantar fasciitis: more that 1 million ambulatory care visits  Ankle sprains: most common sports-related injury  Lateral ankle sprain: at risk for developing chronic ankle instability  May experience hip weakness after an ankle sprain  Low-Back Pain  One of the major forms of musculoskeletal degeneration (80%)  Predominant among workers in enclosed workplaces, as well as manual labor, &ppl who sit longer than 3 hours  > 1/3 of all work-related injuries involve the trunk, &more than 60% of these involve the low back  Knee Injuries  80,000-100,000 ACL injuries annually (US)  70-75% are noncontact  ACL injuries have a strong correlation to acquiring arthritis in the affected knee  Most injuries over b/w 15 & 25 years of age  Shoulder Injuries  21% of the general population (w/ 40% lasting at least a year)  Shoulder impingement is the most prevalent diagnosis (40-65% of shoulder pain)  Persistent nature of shoulder pain may be the result of degenerative changes to the shoulder’s capsuloligamentous structures, articular cartilage, &tendons as the result of altered shoulder mechanics The extent to which we condition our musculoskeletal system directly influences our risk of injury. The Future  The continual decrease in everyday activity has contributed to many of the postural deficiencies seen in people The Corrective Exercise Continuum  Corrective Exercise: The systematic process of identifying a neuromusculoskeletal dysfunction, developing a plan of action, &implementing an integrated corrective strategy  Process requires:  Knowledge &application of an integrated assessment process  Corrective program design  Exercise technique  3 Step Process  Identify the problem (integrated assessment)  Solve the problem (corrective program design)  Implement the solution (exercise technique)  4 Primary Phases  Inhibit  Used to release tension or decrease activity of overactive neuromyofascial tissues in the body  Accomplished through the use of self-myofacial release techniques (foam roller)  Lengthen  Used to increase the extensibility, length, &ROM of neuromuscular tissues in the body  Accomplished through the use of static stretching &neuromuscular stretching.  Activate  used to reeducate or increase activation of underactive tissues.    Accomplished though the use of isolates strengthening exercises &positional isometric techniques  Integrate  Used to retrain the collective synergistic function of all muscles though functionally progressive movements though the use of integrated dynamic movements An integrated assessment process must be done to determine dysfunction &ultimately the design of the corrective exercise program  should include, but not limited to…  Movement assessments  ROM assessments  Muscle strength assessments Will help in determining which tissues need to be inhibited &lengthened &which need to be activated &strengthened through the use of the CEC. CHAPTER 2: Introduction to Human Movement Science  Biomechanics  A study that uses principles of physics to quantitatively study how forces interact w/in a living body  Focus: on the motions that the HMS produces (kinematics) &the forces (kinetics) that act on it  Anatomic Terminology  Planes of Motion    Movements occur predominantly in a specific plane when that movement occurs along or parallel to the plane The Sagittal Plane: - Right &Left  Axis: Frontal  Movements: flexion &extension  Frontal  Front &Back  Axis: Anterior-Posterior  Movements:  Adduction (TOWARD)/Abduction (AWAY)  Lateral Flexion  Eversion/Inversion  Transverse  Upper &Lower  Axis: Longitudinal  Movements:  Internal/External rotation  Left/right spinal rotation  Horizontal add/abduction Combined Joint Motions  Joint Motion: movement in a plane occurs around an axis running perpendicular to that plane  If change in alignment occurs at one joint, changes in alignment of other joints must occur  All freely moveable joints can display some movement in all 3 planes of motion.  Functional Multiplanar biomechanics of the subtalar joint can be simplified into pronation &supination.  Pronation w/ obligatory tibial &femoral internal rotation is a Multiplanar, synchronized joint motion (occurs w/ eccentric muscle function)  Subtalar supination w/ obligatory tibial &femoral external rotation is a multiplanar, synchronized joint motion (occurs w/ concentric muscle function  Gait Cycle (used to describe functional biomechanics to show the interdependence of joint &muscle actions on each other)  During initial contact phase, the subtalar joint pronates creating obligatory internal rotation of the tibia, femur, &pelvis  At mid-stance, the subtalar joint supinates leading to obligatory external rotation of the tibia, femur, &pelvis    Poor control of subtalar joint pronation along w/ tibial &femoral internal rotation decreases the ability to eccentrically decelerate multisegmental motion that can lead to muscle imbalances, joint dysfunction, &injury  Poor production of subtalar joint supination along w/ tibial &femoral external rotation decreases the ability of the HMS to concentrically produce the force for push-off that can lead to synergistic dominance  During functional movement muscles synergistic function: eccentrically decelerate pronation or to concentrically accelerate supination  Poor alignment also changes the mechanical function of muscle and fore-couple relationships of all the muscles that cross the joint  Leads to altered movement patters  Altered reciprocal inhibition  Synergistic dominance  Decreased neuromuscular efficiency Muscle Actions  Eccentric  When a muscle develops tension while lengthening; the muscle lengthens b/c the contractile force is less than the resistive force  (Overall tension w/in muscle is less than the external forces trying to lengthen the muscle)  Resistance training negative  Occurs during lowering phase of any resistance exercise  Integrated resistance training  Eccentric action exerted prevents the resistance from accelerating in an uncontrolled manner downward (gravity)  Muscles must decelerate or reduce the forces acting on the body (or force reduction)  Isometric  When the contractile force is equal to the resistive force (no visible change in the muscle length)  As the muscle shortens the elastic components lengthen (no joint movement)  Dynamically stabilize the body  Concentric  When the contractile force is greater than the resistive force  Resulting in shortening of the muscle and visible joint movement  Integrated resistance training positive Muscular force  Force: interaction b/w two entities or bodies that result in either the acceleration or deceleration of an object  Characterized by:  Magnitudehow strong  Directionwhich way they are moving  Length-Tension Relationships  The resting length of a muscle and the tension the muscle can produce at this resting length  Optimal muscle length: actin and myosin filaments have the greatest degree of overlap  Myosin makes max amt of connections w/ active sites on the actin filament, leading to maximal tension development of that muscle  When the muscle is stimulated at lengths greater than or less than optimaltension is less b/c there are fewer interactions of the myosin cross-bridges and actin active sites  Length of muscle impacts…  Starting point for a lift  Proper posture  Ability (or inability) to develop tension when reactive or correcting a movement  A change in joint angle can affect the tension produced by muscles that surround the joint  If muscle length is altered as a result of misalignment then tension development will be reduced and the muscle will be unable to generate proper force for efficient movement   Force-Velocity Curve and Force-Couple Relationships  Relationship of a muscle’s ability to produce tension at differing shortening velocities  As the velocity of a concentric contraction increases, the development of tension decreases  As velocity increases, ability to develop force increases  Most Muscles transmit force onto their bones, creating movement at joints  Force-couple: synergistic action of muscles to produce movement around a joint  Motion that results from these forces depends on the structure of the joint, the intrinsic properties of each fiber, and the collective pull of each muscle involved Muscular Leverage and Arthrokinematics  A lever system is composed of some force (muscles), a resistance (load to be moved), lever arms (bones), and a fulcrum (the pivot joint).  First Class Lever  Fulcrum b/w force and load  Second Class Lever  Load b/w the force and fulcrum  Third Class Lever (most common in the body)  Pull b/w the load and fulcrum      Bones act as lever arms that move a load from the force applied by the muscles Rotary Motion: movement around an axis Torque: the “turning” effect of the joint In resistance training, torque (distance from the load to the center of the axis of rotation X the force) is applied so the joints can move  The closer the weight is to the point of rotation (the joint) the less torque it creates Functional Anatomy  Agonists: muscles that act as prime movers     Antagonists: muscles that act in direct opposition to prime movers Synergists: muscles that assist prime movers during functional movement patterns Stabilizer: muscles that support or stabilize the body while the prime movers and the synergists perform the movement patterns. Current Concepts in Functional Anatomy:  Joint Support System  Local Muscular System (Stabilization System)  Consists of muscles that are predominantly involved in joint support or stabilization  Muscles that are not movement specific, rather they provide stability to allow movement of a joint  Rotator cuff, posterior fibers of the gluteus medius and external hip rotators vastus medialis, etc.  Joint support system of the core (LPHC) o Muscles that originate or insert into the lumbar spine o Transversus abdominus, multifidus, internal oblique, diaphragm, and muscles of the pelvic floor  Global Muscular Systems (Movement Systems)  Responsible predominantly for movement and consist of more superficial musculature that originate from the pelvis to the rib cage, the lower extremities, or both.  Muscles are predominantly larger and associated w/ movements of the trunk and limbs that equalize external loads placed on the body  Important in transferring and absorbing forces from the upper and lower extremities to the pelvis  Deep Longitudinal Subsystem (DLS)  Major soft tissue contributors: Erector spinae, thoracolumbar fascia, sacrotuberous ligament biceps Femoris, and peroneus longus  Provides a longitudinal means of reciprocal force transmission from trunk to the ground  FIGURE 2.18  Before heel strike, the biceps Femoris activates to eccentrically decelerate hip flexion and nee extension  After heel strike the biceps Femoris is father loaded though the lower leg via posterior movement of the fibula  This tension from the lower leg, up through the biceps Femoris, into the sacrotuberous ligament, and up the erector spinae creates a force that assists in stabilizing the sacroiliac joint (SIJ).  Although the erector spinae and psoas create lumbar extension and an anterior shear force at L4 though S1, during functional movements the local muscular system provides intersegmental stabilization and a posterior shear force.  Posterior Oblique Subsystem (POS)  Works synergistically w/ the DLS  Bot the glutes, and lats have attachments to the thoracolumbar fascia, which connects to the sacrum, whose fibers run perpendicular to the SIJ.  When the contralateral glutes and lats contract, a stabilizing force is transmitted across the SIJ  Before heel strike. The lats and contralateral gluts are eccentrically loaded  At heel strike, each muscle accelerates its respective limb and creates tension across the thoracolumbar fascia  tension assists in stabilizing SIJ  When individual walks or runs, the POS transfers forces that are summated from the muscle’s transverse plane orientation to propulsion in the sagittal plane  POS also of prime importance for rotational activities (golf, baseball, throwing)  Dysfunction can lead to SIJ instability and LBP (low back pain)  Weakening of the gluts and lats can lead to increased tension in the hams  If performed in isolation not enough to prepare POS  Anterior Oblique Subsystem (AOS)   Similar to POS b/c it also functions in a transverse plane orientation, mostly in the anterior portion of the body  Prime contributors: internal and external oblique muscles, adductor complex, and him external rotators  Aid in pelvic stability and rotation as well as leg swing  Factor is the stabilization of the SIJ  When we walk, our pelvis rotates in the transverse plane to create a swinging motion for the legs  Necessary for functional activities involving the trunk and upper and lower extremities  Lateral Subsystem (LS)  Composed of: gluteus medius, tensor fascia latae, adductor complex, Quadratus lumborusall of which participate in frontal plane and pelvofemoral stability  Ipsilateral gluteus medius, tensor fascia latae, and adductors combine w/ the contralateral Quadratus lumborum to control the pelvis and femur in the frontal plane during single leg functional movements such as in gain, lunges, or stair climbing  Dysfunction evident during increased subtalar joint pronation in conjunction w/ increased tibial and femoral adduction and internal rotation during functional activities  Unwanted frontal plane movements is characterized by decreased strength and decreased neuromuscular control in the LS  Functional Anatomy of the Major Muscles  Leg Complex  Hip Complex  Abdominal Musculature  Back Musculature  Arm Musculature  Neck Musculature Motor Behavior  The HMS response to internal and external environmental stimuli the collective study of motor control, motor learning, and motor development  Sensory Information: the data that the central nervous system receives from sensory receptors to determine such things as the body’s position in space and limb orientation, as well as info about the environment, temperature, texture, etc.  How the CNS incorporates the info it receives to produce, refine, manipulate, and remember a movement pattern  Motor Control  The study of posture and movements w/ the involved structures and mechanisms used by the CNS to assimilate and integrate sensory info w/ previous experiences  Concerned w/ what CNS structures are involved w/ motor behavior to produce movement  Sensory Information  Data that the CNS receives from sensory receptors to determine things like the body’s position n space and limb orientation as well as info about the environment, temp, texture, etc.  Essential in protecting the body  Provides feedback about movement to acquire and refine new skills though sensory sensations and perceptions  Sensations: a process by which sensory info is received by the receptor and transferred either to the spinal cord for reflexive motor behavior, to higher cortical areas for processing, or both.  Perceptions: The sensory integration of sensory info w/ past experiences or memories  3 ways the body uses sensory info:  Sensory info provides info about body’s spatial orientation to the environment and itself before, during, and after movement   Assists in planning and manipulating movement action plans (may occur at the spinal level in the form of a reflex or at the cerebellum where actual performance is compared)  Proprioception  The cumulative neural input from sensory afferents to the CNS  One form of sensory (afferent) info that uses mechanoreceptors to provide info about static and dynamic positions, movements, and sensations related to muscle force and movement  This afferent info is delivered to diff. levels of motor control w/in the CNS to use in monitoring and manipulating movement  Altered after injury  W/ many of the receptors being located in and around joints, any joint injury will likely also damage proprioceptive components that could be compromised for some time after an injury  A thorough rehab program after a musculoskeletal injury normally will contain a proprioceptive component  Much of our movement is supported by the global muscular system, reinforcing the need for core and balance training to enhance ones proprioceptive capabilities, increase postural control, and decrease tissue overload.  Muscle Synergies  Simplifies movement by allowing muscles to operate as a functional unit  Through practice of proper movement patterns and technique, these synergies become more fluent and automated  TABLE 2.4 (pg.57)  Sensorimotor Integration  The ability of the CNS to father and interpret sensory info to execute the proper motor response  Only as effective as the quality of the incoming sensory info  An individual who trains w/ improper form delivers improper sensory info to the CNS, which can lead to movement compensation and potential injury  Programs need to be designed to train and to reinforce correct technique Motor Learning  The utilization of these processes though practice and experience leading to a relatively permanent change in one’s capacity to produce skilled movements  Feedback  Necessary to ensure optimal development of these skilled movements  Utilization of sensory information and sensorimotor integration to aid in the development of permanent neural representations of motor patterns for efficient movement  Achieved though…  Internal (sensory) feedback o Process by which sensory info is used by the body via length-tension relationships, force-couple relationships, and arthrokinematics to monitor movement and the environment o Acts as a guide, steering the HMS to the proper force, speed, and amplitude of movement patterns o Proper form during movement ensures that the incoming internal (sensory) feedback is the correct info, allowing for optimal sensorimotor integration for ideal structural and functional efficiency  External (augmented) feedback o Info provided by some external source (ex: health and fitness professional, video, mirror, HR monitor) o Used to supplement internal feedback o Provides another source of info that allows for individual to associate the outcome of the achieved movement pattern (good/bad) w/ what is felt internally o Knowledge of results (KoR)   Used after the completion of a movement to inform individuals about he outcome of their performance  Come from health and fitness professional, the client, or some tech means  Inform individuals that their “squats” were good and ask clients whether they could feel or see their form  By getting clients involved w/ KoR, they increase their won awareness and augment their impressions w/ multiple forms of feedback  Individuals become more familiar w/ technique, KoR from the health and fitness professional should be given less frequently  improves Neuromuscular efficiency o Knowledge of performance  Provides info about the quality of the movement  EX: noticing (during a squat) that feet were externally rotated, asking whether the individual felt or saw anything different about that  Ex: individuals absorb the shock of landing from a jump, telling them to listen to the impact and land quietly, effectively teaching the individual to absorb the shock of landing  Gets the client involved in own sensory process o Client must not become to dependent on external feedback, may detract from individuals own responsiveness to internal sensory input Motor Development: the change in motor behavior over time throughout one’s lifespan CHAPTER 4: Health Risk Appraisal  Readiness for Activity  Physical Activity Readiness Questionnaire (PAR-Q)  Help determine if a person is ready to undertake low-to-moderate-to-high activity levels  Aids in identifying people for whom certain activities may bot be appropriate or who may need further medical attention  Directed toward detecting any possible cardiorespiratory dysfunction, such as coronary heart disease, and is a good beginning point for gathering personal background info concerning one’s cardiorespiratory function  General Lifestyle Information  Occupation  Extended Periods of Sitting  Hips are flexed for prolonged periods of time o Can lead to tight hip flexors that can cause postural imbalances within the kinetic chain  There is a tendency for the shoulders and cervical spine to fatigue under the constant influence of gravity (especially if sitting at a computer) o Leads to a postural imbalance of rounding of the shoulders and a forward head  Repetitive Movements  Can create a pattern overload to muscles and joints, which may lead to tissue trauma and eventually kinetic chain dysfunction  Seen in jobs that require a lot of overhead work (construction and painting) o Working with arms overhead for long periods of time may lead to shoulder soreness that could be the result of tightness in the latissimus dorsi and pectorals and weakness in the rotator cuff o Imbalance does not allow for proper shoulder motion or stabilization during activity, which can lead to shoulder and neck pain  Dress Shoes  Heels put the ankle complex in a plantarflexion position for extended periods o Can lead to tightness in the gastrocnemius and soleus causing postural imbalance, such as over pronation at the foot and ankle complex (flattening of the arch of the foot, which can lead to foot and ankle injury)  Mental Stress (anxiety)   Can lead to a dysfunctional breathing pattern that can further lead to postural distortion and kinetic chain dysfunction Life Style  Recreation  Individual’s physical activities outside of the work environment  Can better design a program to fit these needs  Ex: if they like to gold, ski, play tennis, or engage in a variety of other sporting activities in their spare time   Proper program strategies must be incorporate to ensure that individuals are trained in a manner that optimizes the efficiency of the human movement system, while addressing potential muscle imbalances that may be a result of their activity  Hobbies  Refer to activities that an individual may partake in regularly, but are not necessarily athletic in nature  EX: Gardening, working on cars, reading, watching TV, video games  In many cases, the individual must maintain a particular posture for an extended period of time, lending to potential muscle imbalances Medical History  Provides info about any life-threatening chronic disease, as well as info about the structure and function of the individual by uncovering important info like past injuries, surgeries, imbalances, and chronic conditions .  Past Injuries  Beyond the risk of suffering the same injury again or compensating for an incompletely rehabilitated injury leading to another injury, a prior injury can also have effects up and down the kinetic chain  Ankle Sprains o Decrease the neural control to the gluteus medius and gluteus maximus o Can lead to poor control of the lower extremities during many functional activities, which can lead to injury  Knee Injuries involving ligaments o Can cause a decrease in the neural control to muscles that stabilize the patellofemoral and tibiofemoral joints and lead to further injury o Noncontact knee injuries are often the result of ankle or hip dysfunctions o The knee is caught between the ankle and the hip o If the ankle or hip joint begins to function improperly this results in altered movement and force distribution of the knee (can lead to further injury over time)  Low-back injuries o Can cause decreased neural control to stabilizing muscles of the core, resulting in poor stabilization of the spine o Can lead to dysfunction in upper and lower extremities  Shoulder injuries o Cause altered neural control of the rotator cuff muscles, which can lad to instability of the shoulder joint during functional activities  Other injuries o Result from HMS imbalances include repetitive hamstring complex strains, groin strains, patellar tendonitis (jumper’s knee), plantar fasciitis (pain in the arch of the foot), posterior Tibialis tendonitis (shin splints), biceps tendonitis (shoulder pain) and headaches  Individuals can only recall about half of their history Past Surgeries  Create trauma for the body and may have similar effects to those of an injury  Can create dysfunction, unless properly rehabilitated  Common procedures:  Foot and ankle surgery  Knee surgery  Shoulder surgery     Cesarean section for birth (cutting through the abdominal wall to deliver a baby)  Appendectomy (cutting through the abdominal wall to remove the appendix)  Surgery will cause pain and inflammation that can alter neural control to the affected muscles and joints if not rehabilitated properly Chronic Conditions  Health and Fitness Professional will work not only with relatively healthy clients, but also with clients with any number of chronic diseases like…  Cardiovascular disease, coronary artery disease, congenital heart disease, valvular disorders, or congestive heart failure  Hypertension (high blood pressure)  High cholesterol or other blood lipid disorders  Stroke or peripheral artery disease  Lung or breathing problems from smoking, asthma, obstructive pulmonary diseases or exposure to inflammatory stimuli  Obesity in children or adults  Type 1 or type 2 diabetes mellitus  Cancer Medications  It is NOT the role of a Health and Fitness Professional to administer, prescribe, or educate on the usage and effects of any of these m1edications. CHAPTER 5: Static Postural Assessment   Static Posture: How an individual physically presents themselves in stance. It is reflected in the alignment of the body Dynamic Posture: How an individual is able to maintain an erect posture while performing functional tasks  Importance of Posture as it Relates to Injury  Provides excellent indicators of problem areas that must be further evaluated in order to clarify problems at hand  Allows for intervention at the level of the causative factor rather than treating the symptomatic complaints Muscle Imbalance  Myofascial: the connective tissue in and around muscles and tendons  The body will continually adapt in an attempt to produce the functional outcome requested by the system.  This adaptability will lead to imbalances and eventually to imbalances that move beyond a dysfunctional and into tissue damage and pathology  The muscle-tendon units will shorten or lengthen as the stressors demand  Can result in the stabilizing muscles being less efficient to stabilize joints as they are pulled out of optimal alignment  Muscle Imbalance: Alteration in the functional relationship between pairs or groups of muscles  Appear to be systematic  Certain muscles are prone to shortening while others are susceptible to lengthening and weakness (inhibition) How Do Alterations in Static Posture Occur  Main Factors that cause postural imbalance:  Habitual movement patterns  The body tends to not readjust itself to neutral after being in a bad position and continues to move in the imbalanced position, even when not loaded  Driving use of right lower extremity without awareness of trying to maintain symmetry  Workstations neck and arm dysfunction  Computer monitor  Over-stuffed briefcases just one side of the body  Altered movement patterns from repetitive movement  (Chronic overuse or injury) can lead to a change in the elasticity of the muscle       Poor posture and lack of daily movement are also considered a contributing factor Muscle that is repeatedly placed in a shortened position (ex: Iliopsoas) will eventually adapt and remain short  Repetitive movements can cause imbalances by placing demands on certain muscle groups more predominantly o Swimmersover emphasized pectoral muscles in relationship to scapular retractors (rounded shoulder posture) o Runners, tennis players o Construction workershammering o Waiters and waitresses  large trays with same hand o Gym people who focus on certain muscle groups and not others  Altered movement patters form injury  May assume adaptive postures to avoid pain or to create function  Doesn’t change after healed unless reminded to return to a more normal pattern  The changing use patterns alters loads across the joints and alters recruitment strategies of muscles (all leading to muscular imbalances reflected in postural change)  Hypermobility: restricted motion  Injury may also result in tissue that becomes restricted (hypermobility) o Immobilizations through splinting or self-immobilization due to pain ma allow tissue to shorten  Without restoring mobility, the reciprocal muscles are lengthened, creating weakness  Muscles that are too short and tight are functionally paired with muscles that are lengthened and weak, disrupting the neuromuscular balance in the interdependent relationship  Altered movement patterns from surgery  Scar mobility is often an overlooked aspect of rehab  Lack of mobility alters the alignment and pulls on the fascia, effecting joints and muscle function  Altered movement patterns from incompletely rehabilitated injuries  The health and fitness professional’s job is to identify those muscle imbalances, identify the causative agents, and institute a comprehensive corrective exercise program o Postural assessment is the first step Common Distortional Patterns  Most structures and muscle groups have very defined functional roles  Although they may be appropriately used to create more than one movement  Quads: flex the hip or extend the knee  When asked to provide rotational stability at the knee, quads may be hypertrophied from the overtaxing use or result in symptomatic complains of inrapatella tendonitis, anterior knee pain or patellofemoral dysfunction  Hips: shifted off of midline may indicate load-bearing habits to one side and may be reflective of imbalances in the pelvis as a result  Body has a tendency to compensate in particular patterns or by particular relationships between muscles  Patterns studied and described by Janda (1970s)  Florence and Henry Kendall studied these patterns and took an alternative approach (through the relationship of agonist-antagonist)  continued by Shirley Sahrmann Janda’s Postural Distortion Syndromes  Three basic compensatory patterns  Lower Crossed Syndrome: a postural distortion syndrome characterized by an anterior tilt to the pelvis and lower extremity muscle imbalances  Increased lumbar lordosis and anterior pelvic tilt  Tight: gastrocnemius, soleus, adductor complex, hip flexor complex (psoas, rectus Femoris, tensor fascia latae), latissimus dorsi, and erector spinae  Weak: posterior tibialis, anterior Tibialis, gluteus maximus, gluteus medius, transverse abdominus, internal oblique   Associated joint dysfunctions: subtalar joint, tibiofemoral joint, iliofemoral joint, sacroiliac joint, and lumbar facet joints  Common movement dysfunctions: decreased stabilization of lumbar spine during functional movement o Squatting, lunching, or overhead pressing  Common injury patterns: hamstring strains, anterior knee pain, low-back pain  Upper Crossed Syndrome: a postural distortion syndrome characterized by a forward head and rounded shoulders with upper extremity muscle imbalances  Rounded shoulders and a forward head posture  Tight: pectoralis major, pectoralis minor, subscapularis, latissimus dorsi, levator scapulae, upper trapezius, teres major, sternocleidomastoid, and scalenes  Weak: rhomboids, lower trapezius, teres minor, infraspinatus, serratus anterior, and deep cervical flexors  Potential joint dysfunctions: sternoclavicular joint, acromioclavicular joint, thoracic and cervical facet joints  Injury patterns: rotator cuff impingement, shoulder instability, biceps tendinitis, thoracic outlet syndrome, and headaches  Pronation Distortion Syndrome: a postural distortion syndrome characterized by foot pronation and lower extremity muscle imbalances  Excessive foot pronation (flat feet), knee flexion, internal rotation, and adduction (“knocked-knees”)  Tight: peroneals, gastrocnemius, soleus, IT band, hamstrings, adductor complex, and psoas  Weak: posterior tibialis, anterior tibialis, vastus medialis, gluteus medius, gluteus maximus and hip external rotators  Joint dysfunctions: first metatarsophalangeal joint, subtalar joint, talocural joint, sacroiliac joint, and lumbar facet joints  Patterns of injury: plantar fasciitis, posterior tibialis tendinitis (shin splints), patellar tendonitis, and low-back pain Systematic Approach to Assess Static Posture  Kinetic Chain Checkpoints  Foot and ankle  Anterior View: straight and parallel, not flattened or externally rotated  Lateral View: neutral position, leg vertical at right and angle to sole of foot  Posterior View:  Knee  Anterior View: in line with toes, not adducted or abducted  Lateral View: Neutral position, not flexed nor hyperextended  Posterior View:  LPHC  Anterior View: Pelvis level with both posterior superior iliac spines in same transverse plane  Lateral View: Pelvis in neutral position, not anteriorly (lumbar extension) or posteriorly rotated (lumbar flexion)  Posterior View:  Head/cervical spine (upper body)  Anterior View: neutral position neither tilted nor rotated  Neutral position, not in excessive extension (“jutting” forward)  Posterior View: CHAPTER 6:  The Scientific Rationale for Movement Assessments  Movement represents the integrated functioning of many systems within the human body, primarily the muscular, skeletal, and nervous systems  Form an interdependent triad that, when operating correctly, allows for optimal structural alignment, neuromuscular control (coordination), and movement     Important to establishing normal length-tension relationships, which ensue proper length and strength of each muscle around a joint  Muscle Imbalance: establishing normal length-tension relationships, which ensure proper length and strength of each muscle around a joint Muscle balance is essential for optimal recruitment of force-couples to maintain precise joint motion and ultimately decrease excessive stress place on the body This translates into the efficient transfer of forces to accelerate, decelerate, and stabilize the interconnected joints of the body and is the source from which the term kinetic chain is derived  Kinetic Chain: “kinetic” denotes the force transference from the nervous system to the muscular and skeletal systems as well s from joint to joint, and “chain” refers to the interconnected linkage of all joints in the body (HUMAN MOVEMENT SYSTEM) When HMS impairments exist, there are muscles that are overactive and muscles that are underactive around a joint (Underactive are the ones that really matter) Typically Overactive Muscles  Gastrocnemius  Typically Underactive Muscles  Soleus  Anterior tibialis  Adductors  Posterior tibialis  Hamstring complex  Vastus medialis oblique  Psoas (VMO)  Tensor fascia latae  Gluteus maximus/medius  Rectus Femoris  Transverse abdominus  Piriformis  Internal oblique  Quadratus lumborum  Multifidus  Erector spinae  Serratus anterior  Pectoralis major/minor  Middle/lower trapezius  Latissimus dorsi  Rhomboids  Teres major  Teres minor  Upper trapezius  Infraspinatus  Levator scapulae  Posterior deltoid  Sternocleidomastoid  Deep cervical flexors  Scalenes  This result in an altered recruitment strategy and ultimately an altered movement pattern  Alternations in muscle activity will change the biomechanical motion of the joint and lead to increased stress on the tissues of the joint, and eventual injury  Movement assessment allows professional to observe for HMS impairments including muscle imbalances (length and strength deficits) and altered recruitment strategies  Can then be correlated to subjective findings and isolates assessments such as goniometric and manual muscle testing  Data will produce a more comprehensive representation of the client or patient and thus a more individualized corrective exercise strategy Types of Movement Assessments  Transitional Movement Assessments: assessments that involve movement without a change in one’s base of support  Overhead Squat - Purpose o Assess dynamic flexibility, core strength, balance, overall neuromuscular control o Measure of lower extremity movement patters during jump landing tasks - Procedure o Stand with feet shoulder width apart and pointed straight ahead. Foot and ankle should be in a neutral position (suggested that assessment be performed without shoes) o Raise arms overhead, with elbows fully extended (upper arm should bisect the torso) o Squat to roughly height of a chair and return to starting position   Repeat for 5 repetitions, observing from each position  Anterior - Feet should remain straight with the knees tracking in line with the foot (2nd & 3rd toes) - Compensations:  Feet:  Do they flatten and/or turn out?  Flatten:  Knees:  Do they move inward (adduct and internally rotate?)  Do they move outward (abduct and externally rotate?)  Lateral - Tibia should remain in line with the torso while the arms also stay in line with the torso - Compensations:  LPHC:  Does the low back arch (excessive spinal extension)?  Does the low back round (excessive spinal flexion)?  Does the torso lean forward excessively?  Shoulder:  Do the arms fall forward?  Posterior - Foot and ankle complex will demonstrate slight pronation, but the arch of the foot will remain visible - Feet should also remain straight while the heels stay in contact with the ground - LPHC should not shift from side to side - Compensations:  Feet:  Do the feet flatten (excessive pronation)?  Do the heels rise off the floor?  LPHC:  Is there an asymmetric weight shift? - MODIFICATIONS o Elevating Heels o Hands on Hips Single-Leg Squat  Purpose o Lower extremity movement patterns when standard application protocols are applied  Procedure o Should stand with hands on the hips and eyes focused on an object straight ahead o Foot should be pointed straight ahead and the foot, ankle, knee, and the LPHC should be in a neutral position o Squat to a comfortable level and return to the starting position o Perform up to 5 repetitions before switching sides  Anterior - Knee should track in line with the foot - LPHC and shoulders should remain level and face straight ahead - Compensations:  Knee:  Does the knee move inward (adduct and internally rotate)?  LPHC:  Does the hip hike?  Does the hip drop? o       Does the torso rotate inward? Does the torso rotate outward? Push-Up  Purpose o Evaluates the function of the LPHC and the scapular and cervical spine stabilizers  Procedure o Assume a prone position with hands shoulder width apart and knees fully extended (a modified version of the push-up can also be used depending on the capabilities of the individual o Push against the floor, displacing the thorax backward until the scapulae are in a position of protraction o Move slowly and consistently as most faults will not be exhibited until the individual is fatigued (a 2-0-2 speed per repetition is recommended two seconds up, zero-second hold, two seconds down) o Perform 10 repetitions  Compensations: - LPHC:  Does the low back sag?  Does the low back round? - Shoulders:  Do the shoulders elevate?  Does the scapulae wing (lift away from the rib cage)? - Head/cervical Spine:  Does the head migrate forward? Standing Cable Row  Purpose o Evaluates the function of the LPHC and the scapular and cervical spine stabilizers  Procedure o Stand in a staggered stance with the toes pointing forward o Pull handles toward body and return to the starting position o The lumbar and cervical spines should remain neutral while the shoulders stay level o Perform 10 repetitions in a controlled fashion using a 2-0-2 tempo  Compensations: - Low Back:  Does the low back arch? - Shoulders:  Do the shoulders elevate? - Head:  Does the head migrate forward? Standing Overhead Dumbbell Press  Purpose o Evaluates the function of the LPHC, scapular stabilizers, and cervical spine stabilizers as well as shoulder ROM  Procedure o Stand with feet shoulder width apart and toes pointing forward o Choose a dumbbell weight at which the individual can perform 10 repetitions comfortably o Instruct to press the dumbbells overhead and return to the starting position o The lumbar and cervical spines should remain neutral while the shoulders stay level and the arms bisect the ears o Perform 10 reps in a controlled fashion using a 2-0-2 tempo  Compensations: - Low Back:  Does the low back arch? Shoulders:  Do the shoulders elevate?  Do the arms migrate forward?  Do the elbows flex? - Head:  Does the head migrate forward? Star Balance Excursion  Purpose o Measures Multiplanar balance and neuromuscular efficiency of the testing leg during closed-chain functional movements  Procedure o Stand on the testing leg o Squat down as far as he or she can control with the knee aligned in a neutral position (balance threshold)  Balance Threshold: the distance one can squat down on one leg while keeping the knee aligned in a neutral position (in line with the second and third toes) o Reach with the opposite leg in the sagittal, frontal, and transverse planes while trying to maintain balance and keeping the knee in line with the second and third toes of the balance foot o The health and fitness professional assesses in which plane of motion the individual has the least amount of control (ie. Cannot maintain balance or knee moves inward) o Can help in determining which plane(s) of motion may need to be emphasized in the individual’s corrective exercise strategy Upper Extremity Assessments  Purpose o Determine any specific movement deficits in the shoulder complex  Procedure o Standing with heels, buttocks, shoulders, and head against a wall (the low back should be held in a neutral lumbar position) o Horizontal Abduction Test  Raise both arms straight out in front to 90 degrees of flexion with the thumbs up  Keeping the elbow extended, horizontally abduct the arms back toward the wall  Properly performed, the back of the hands will touch the wall with no movement compensations o Rotation Test  Abduct the shoulders to 90 degrees and bend the elbows to 90 degrees  With each humerus parallel to the floor, internally rotate the palms toward the floor then externally rotate the arms back toward the wall  The goal is to internally rotate the humerus until the palms of the hands and the forearms are within 20 degrees of the wall, then to externally rotate the humerus to touch the back of the hands against the wall with no movement compensations in either direction. o Shoulder Flexion Test  Elbows are extended with thumbs up, then the straight arms are extended straight up toward the wall  The goal is to touch the thumbs against the wall with no compensatory movements such as shrugging or increasing lumbar lordosis  Compensations: o Horizontal Abduction Test  Do the shoulders elevate? -     Do the shoulders protract?  Do the elbows flex? o Rotation Test  Do the shoulders elevate (internal rotation)?  Do the shoulders protract (internal rotation)?  Are the hands far from the wall (internal and external rotation)? o Shoulder flexion Test  Do the shoulders elevate?  Does the low back arch?  Do the elbows flex? Dynamic Movement Assessments: assessments that involve movement with a change in one’s base of support  Gait: Treadmill Walking  Purpose o To assess one’s dynamic posture during ambulation  Procedure o Walk on a treadmill at a comfortable pace at a 0-degree incline o Observe feet and knees  Feet should remain straight with the knees in line with the toes o Observe the low back, shoulders, and head  Low back should maintain a neutral lordotic curve  Shoulders and head should also be in neutral alignment o Observe the feet and LPHC  The feet should remain straight and the LPHC should remain level o Compensations:  Anterior View - Feet  Do the feet flatten and/or turn out? - Knees  Do the knees move inward?  Lateral View - LPHC  Does the low back arch? - Shoulders and Head  Do the shoulders round?  Does the head migrate forward?  Posterior View - Feet  Do the feet flatten and/or turn out? - LPHC  Is there excessive pelvic rotation?  Do the hips hike?  Landing Error Scoring System (LESS) Test  Purpose o Identifying improper movement patterns during the jump landing tasks o Evaluates landing technique based on nine jump landing concepts using 13 different yes or no questions  Procedure o Stands on a 30-cm box o A target line is drawn on the floor at a distance of half the individual’s height o Instructed to “jump forward from the box with both feet so that you land with both feet just after the line” and “as soon as you land, jump up for a maximum height and land back down.” o Views a demonstrations performed by the health and fitness professional, then gets the opportunity to practice o   Ideally, video cameras are placed 10 ft. in front and to the right of the landing area Three trials are performed o   Tuck Jump Test  Purpose o Tuck jump requires a high effort level from the individual o Initially, the individual may place most of his or her cognitive efforts solely on the performance of this difficult jump o Identify potential deficits especially during the first few repetitions  Procedure o Repeated tuck jumps for 10 seconds, which allows the health and fitness professional to visually grade the outlined criteria o To further improve the accuracy of the assessment, a standard two-dimensional camera in the frontal and sagittal planes may be used to assist the health and fitness professional o Rated as either having an apparent deficit (checked) or not (deficits evaluated) o Deficits are tallied for the final assessment score o Indicators for flawed techniques should be noted for each individual and should be the focus of feedback during subsequent training sessions o Baseline performance can be compared with repeated assessments performed at the midpoint and conclusion of training protocols to objectively track improvement with jumping and landing technique o Empirical laboratory evidence suggests that individuals who do not improve their scores, or who demonstrate six or more flawed techniques, should be targeted for further technique training  Upper Extremity Davies Test  Purpose o Measures upper extremity agility and stabilization o This assessment may not be suitable for individuals who lack shoulder stability  Procedure o Two pieces of tape on the floor (36 in apart) o Have individual assume a push-up position, with one hand on each piece of tape o Quickly move the right hand to touch the left hand o Perform alternating touching on each side for 15 seconds o Repeat for 3 trials o Record the number of lines touched by both hands o Reassess in the future to measure improvement of number of touches and improvements in movement efficiency Kinetic Chain Checkpoints  Foot and Ankle  Knee  LPHC  Shoulders and head/cervical spine (upper body)  Each joint region has a specific biomechanical motion that is produced based on its structure and function s well as the joints above and below it  When that specific motion deviates from its normal path, it is considered a compensation and can be used to presume possible human movement system impairments (muscle imbalance) Assessment Implementation Options CHAPTER 9: Inhibitory Techniques: Self-Myofascial Release  Self-myofascial release: a flexibility technique used to inhibit overactive muscle fibers  INHIBIT (first steps of corrective exercise continuum)   Cumulative Injury Cycle  Trauma (creates inflammation)  Inflammation (activates the body’s pain receptors and initiates a protective mechanism, increasing muscle tension and causing muscle spasm)  Muscle spasms (are not like a calf cramp…heightened activity of muscle spindles in particular areas of muscle create a microsmasm)  Adhesions (as a result of the spasm”knots” or “trigger points”)  Form a weak, inelastic matrix that decreases normal elasticity of the soft tissue  The result is altered length-tension relationships (leading to synergistic dominance), and arthrokinetic dysfunction (leading to altered joint motion).  These adhesions can begin to form permanent structural changes in the soft tissue  Davis’s Law: States that soft tissue will model along the lines of stress  Relative flexibility: the phenomenon of the human movement system seeking the path of least resistance during functional movement patters (or movement compensation)  SMR may help in releasing the microspasms that develop in traumatized tissue and break up the fascial adhesions that are created through the cumulative injury process, thus potentially improving the tissue’s ability to lengthen through stretching techniques. SMR used for 2 primary reasons  Alleviate trigger points & their side effects  Focus of hyperirritability (sensitivity) in a muscle taut (tight) band (when pressedtwitch response & tenderness &/or pain) - Pain is referred (away from area being pressed)  GTO receptor responds to tension  It has been shown that static tension placed on the musculotendinous unit activates the GTO, which is suggested to produce autogenic inhibition - Autogenic inhibition: inhibition of the muscle spindle resulting from the Golgi tendon organ stimulation  SMR is believed to stimulate the GTO receptors through sustained pressure at a specific intensity, amount, and duration to produce an inhibitory response to the muscle spindle and decrease gamma loop activity. - Gamma Loop: the reflex arc consisting of small anterior horn nerve cells and their small fibers that project to the intrafusal bundle and produce its contraction, which initiates the afferent impulses that pass through the posterior root to the anterior horn cells, inducing, in turn, reflex contraction of the entire muscle. - Reports show that ischemic compression (pressure from an object) at high intensity (maximal pain tolerance) for a low duration (30 seconds) or at a low intensity (minimal pain threshold) for a longer duration (90 seconds) significantly reduced pain and trigger point sensitivity. (insufficient blood supply) - When applied in conjunction with stretching techniques, it was shown to significantly increase range of motion - By holding pressure on the tender areas of tissue (trigger points), trigger point activity can be diminished - Allows for application of a stretching (or lengthening) technique such as static stretching to increase muscle extensibility of the shortened muscles and provides for optimal length-tension relationships - Results in decrease in pain and MTrP (myofascial trigger points) sensitivity  To influence the autonomic nervous system  Type I and II (20% of receptor pool) - Muscle spindle, GTO, Pacini corpuscles, Ruffini endings  Type III and IV - Interstitial receptors) - Pain receptors - Significant to help decrease the overall effects of stress (emotional or physical) on HMS Increasing vasodilation, the tissue can receive adequate oxygen and nutrients as well as removal of waste byproducts (via blood) to facilitate tissue recovery and repair  Healthy tissue may be less predisposed to alter muscle recruitment patterns that may cause injuries o Changing the viscosity of the tissue allows for better tissue dynamics, which may provide better overall muscle contraction and joint motion o Decreasing sympathetic tone reduces the prolonged faulty contraction of muscle tissue that can lead to the cumulative injury cycle o Affecting respiration can lead to better oxygen content in blood as well as decrease feelings of anxiety and fatigue  Faulty breathing patterns can alter carbon dioxide and oxygen content of blood, which perpetuates dysfunctional breathing and leads to synergistic dominance of secondary breathing muscles  Fluid properties of tissue (decreased viscosity/thickness of tissue/resistance to flow or motion)  Hypothalamus: increase vagal tone (relax-nerve) and decreases global muscle tone  Smooth muscle cells in fascia: decreased pre-tension  The importance of the effect neuromyofascial release or pressure and tension has on the ANS is that it influences…. - The fluid properties of tissue that affects the viscosity (resistance to flow or motion) - The hypothalamus, which increases vagal tone and decreases global muscle tonus - Smooth muscle cells in fascia that may be related to regulation of fascial pretension The effects of Tissue Pressure  Sustained or slow tissue pressure stimulates mechanoreceptors that send information to the central and autonomic nervous systems  The CNS response changes the muscle tonus (or decreases hypertonicity) in skeletal muscle  The ANS response also changes global muscle tonus as well as fluid dynamics to decrease viscosity and the tonus of the smooth muscle cells located in fascia Application Guidelines for SMR  Rollers (cylindrical)  Foam Roller/ PVC Pipe - Diameter of 6 inches to start - Start bigger end smaller (diameter) - Soft rollers, which are less rigid and compress more, must be used on a firm surface such as the floor - Less expensive method and easy to learn - More difficult to control the depth of penetration into the soft tissue with a roller in comparison with other SMR tools  Balls  Progression from large diameter ball (medicine ball) to a smaller diameter (tennis, soft ball, baseball, golf ball)  Difficult to control depth of penetration into the soft tissue with a ball than with other SMR tools  Hand Rollers  Some stiff and resist bending, others more flexible and bend considerably while being used  User controls amount of force that the handheld roller puts on the soft tissue  Greater the applied force, the deeper the penetration  Flexible handheld roller offer more surface area contact, but will require more force to penetrate as deeply as a stiff roller  Easier to control depth of penetration into the soft tissue  Instrument-Assisted soft tissue mobilization  Come in different shapes and sizes and are constructed from different materials including plastic, ceramic, and stainless steel  Useful to address hard to reach areas, such as lumbar spine, as well as areas where other SMR modalities may not be suitable, such as the neck region o       Provide the user with a better mechanical advantage to apply pressure comfortably  User controls amount of force that the handheld instrument puts on the soft tissue  The area treated can be very precise depending on the size and shape of the instrument  Vibration or percussion devices  Usually require a second individual to apply the massager to the desired regions while the client is lying down relaxed to ensure optimal results Key application points for self-myofascial release  Make sure the client maintains proper postural alignment while performing SMR  Instruct client to maintain the drawing-in maneuver (pulling the navel in toward the spine) at all times to provide stability to the lumbo-pelvic-hip complex during treatment  The client may use his or her extremities to alter the amount of weight on the treatment area to decrease or increase pressure on the soft tissue  Ex: when foam rolling the calves, the client may cross the free leg over the treated leg to increase pressure or keep the legs uncrossed to decrease pressure  The client should roll the device slowly over the treatment area. He or she should not roll the device over the area quickly to decrease the risk of further tissue excitation  Remember the goal is to inhibit the overactive tissue  Instruct the client to relax and not tighten up while working on an area. Tension in the tissue being treated will prevent the roller from penetrating into the deeper layers of soft tissue  Instruct the client to pause the rolling action over painful areas until a “release: is felt in the area or the pain subsides and the tissue softens (roughly 30 seconds with maximal pain tolerance and 90 seconds for lower pain tolerance)  Areas that have myofascial restrictions will be more painful to mobilize. As soft tissue restrictions break down with subsequent session, treatment will become less painful Precautions and Contradictions  Avoided by people with congestive heart failure, kidney failure, or any organ failure such as the liver and pancreas, bleeding disorders, and contagious skin conditions  List on pg. 214  Drain blood AWAY from injuries Acute Variables  Only once a day for 30-90 seconds per area CHAPTER 10: Lengthening Techniques  Static Stretching  Frequency: Daily (unless specified otherwise)  Repetitions: 1-4  Duration of each repetition: 20-30 second hold (60 second hold for older patients)  Combines low force with long duration without using autogenic inhibition  Allows for relaxation and concomitant elongation of muscle  To properly perform, the stretch is held at the first point of tension or resistance barrier for 30 seconds. It is theorized that this form of flexibility decreases muscle spindle activity and motor neuron excitability  Mechanically:  Viscoelastic component of neuromyofascial tissue  Probable decrease in passive resistance a muscle has to a stretch force throughout most of the ROM and not the rate at which the muscle-tendon unit increases its stiffness.  Although a muscle may not be as resistant to being stretched (allowing for better extensibility), it still maintains the rate of increase in stiffness in response to stimuli (the ability to respond to a stretch force).  Neurologically:  Decreases motor neuron excitability, possibly through the inhibitory effects from the Golgi tendon organs (autogenic inhibition) as well as possible contributions from the Renshaw recurrent loop (Recurrent inhibition) - Recurrent inhibition: a feedback circuit that can decrease the excitability of motor neurons via the interneuron called the Renshaw cell.    These may decrease the responsiveness of the stretch reflex and increase the tolerance a person has to stretch and thus allow for increased ROM - A muscle contraction in response to stretching within the muscle  20-30 seconds causes an acute viscoelastic stress relaxation response, allowing for an immediate increase in ROM  Long term, the increases in maximal joint ROM may be caused by increased tolerance to stretch and not necessarily changes in the viscoelastic properties of myofascial tissue or a possible increase in muscle mass and added sarcomeres in series  Characterized by…  Elongation of neuromyofascial tissue and to end-range and statically holding that position for a period of time  Maximal control of structural alignment  Minimal acceleration into and out of the elongated (stretch) position Neuromuscular Stretching  Frequency: Daily (unless specified otherwise)  Repetitions: 1-3  Duration of each repetition:  Contraction 7-15  Stretch 20-30  Intensity submaximal, approximately 20-25% of maximal contraction  Aka. Proprioceptive neuromuscular facilitation (PNF)  Involves taking the muscle to its end ROM actively contracting the muscle to be stretched for 7-15 seconds then passively moving the joint to a new end ROM and holding this position for 20-30 seconds  Can be repeated several times to achieve a change in joint ROM  Typically neuromuscular stretching involves the aid of a partner to provide a resistance to the active muscle contraction, and passively stretch the joint into the new ROM  Combines benefits of both static and active stretching while keeping the risk of tissue injury low  Studies have shown NMS to be equally effective at increasing ROM when compared with static stretching, and NMS to be more effective and impact muscular power less than static stretching.  Characterized by…  Taking the muscle to its ROM  Active contraction of the muscle being stretched  Passively (or actively) moving to a new end ROM  Statically holding new position for 20-30 seconds and repeating 3 times  Involves a process of isometrically contracting a desired muscle in a lengthened position to induce a relaxation response on the tissue, allowing it to further elongate  Believed that the isometric contraction decreases motor neuron excitability as a result of stimulation of the GTO and that this leads to autogenic inhibition, resulting in decrexased resistance to a change in length (or ability to increase length of tissue).  After contraction latency period characterized by substantial decrease in motor neuron excitability that is said to last up to 15 seconds  NMS usually requires the assistance of another person Traditional Theory Behind Stretching (p. 224 pictures)  The compliance (or flexibility) of the musculotendinous unit affects the relative amount of energy absorbed by the muscle and tendon:  High compliance (increased flexibility)= decrease in muscle energy absorption  Low compliance (decreased flexibility)= increased musclevggvverfr4455 energy absorption  Increase muscle energy absorption= increased force and trauma to muscle fibers  Increasing musculotendinous flexibility through stretching will lead to a decrease in muscle energy absorption and trauma to muscle fibers with a decrease injury risk being the potential result  The stiffness of the musculotendinous unit influences the work required to move the limb:  High stiffness (decreased flexibility)  increased work required  Low stiffness (increased flexibility)  decreased work required  Decreased flexibility limits joint ROM     Decreasing muscle stiffness through stretching will decrease the work required to preform a particular activity and potentially increase overall performance  Research indicated that pre-stretching negatively impacts force production (performance) and may not influence injury risk  Theory is that stretching can affect the structural and neurologic components of muscle, which can lead to an inability of the muscle to effectively generate force  Conflict  “should stretching be performed to improve performance and decrease the risk of injury?” Improving ROM  Sources find that stretching, both acutely and chronically, increase the ROM at the target joint  Especially in hamstring complex (one of the most widely examined muscle groups  Several researchers suggest that each joint and muscle group may respond differently to stretching protocols  Each tissue to be stretched should be carefully evaluated, and the stretching protocol may need to be different for each ROM limitation found  Clinicians should carefully evaluate each tissue through appropriate assessments, and frequently reevaluate movement, to determine whether a protocol is effective at changing ROM  Studies (Brandy and colleagues) found that static hamstring stretches need to be held for 30 seconds, and performed 5 times a week for 6 weeks, to produce significant changes in knee extension ROM  Still need to investigate how weekly stretching frequency may impact chronic gains in ROM  Unclear whether stretching should be performed daily or can be performed as few as 3 times a week to produce significant changes  Some studies suggest that ROM improvements are negated after 4 weeks of no stretching, others have found that stretching does improve long-lasting ROM  Majority of research done using static stretching, so the durations, frequencies, and long-term changes that are attributable to active or NMS stretching need further study  Some evidence suggests that NMS or active stretching protocols can produce greater gains in ROM compared with static stretching, and that these gains may occur more quickly  Recently researchers have examined the impact of stretching not only the tissues that are lengthened during joint movement, but also the agonists to the movement.  Clark and colleagues examined how stretching tight Ipsilateral quads and hip flexor musculature would impact hip flexion ROM  Found that lengthening the quads and hip flexors significantly improved hip flexion, ROM, suggesting that multiple soft tissues surrounding the joint impact the available ROM  Sullivan and colleagues also found that the tilt position of the pelvis influenced ROM gains more than stretching alone, further suggesting that the overall movement of a joint is dependent on the optimal length and positioning of all tissues Improving Athletic Performance  A number of studies have found that pre-exercise stretching causes a loss of one-repetition maximal strength, as well as vertical jump height and sprint speed, when compared with a no-stretching control  Effect appears to last less than 10 minutes (some studies have found that strength may e impaired up to one hour after the stretching protocol  Several studies have also found that pre-exercise stretching does not impair strength or power production acutely  The effect of stretching on acute changes in strength and power may be partially explained by the type of stretching protocol used  Generally, static stretching held for at least 30 seconds does appear to decrease muscular strength and power, whereas ballistic or NMS stretching does not have the same effect  Chronic, long-term stretching protocols have produced varied effects on athletic performance  ROM is typically improved, other variables such as muscular strength, power, vertical jump, sprint speed, agility, or balance have not found the same consistent response Prevention of Injury  Warm-ups    Current evidencepreexercise stretching does not have a significant impact on injury risk or rates, although the effects of chronic, long-term stretching protocols tend to lead to decreased injury rates  Regular, long-term stretching can lead to a decreased incidence of injury decreased cost of time lost from injury, and that fewer severe muscle/tendon injuries occurred in the stretched subjects compared with control subjects  In all of the studies, there does not appear to be any negative consequences relative to injury risk when implementing a regular or pre-exercise stretching program Summary of the Evidence  There is moderate evidence to indicate that regular stretching improves ROM, strength, and performance and decreases injury risk in healthy individuals without identified limitations in flexibility  There is moderate evidence to indicate that acute, pre-exercise stretching performed in isolation decreases strength and performance and does not affect injury risk in healthy individuals without identified limitations in flexibility Limitations of the Research and Improving Effectiveness  Research was not performed on individuals with limited flexibility  Pre-exercise stretching may have positive effects on performance and injury risk in those who are inflexible  Research focused primarily on stretching as the sole exercise  Flexibility is only one piece to maximizing performance and decreasing injury risk  An integrated continuum may have different results - Inhibit  stretch  activate  integrate into functional movement  Address an individuals specific needs based on the assessment  Research has taken a “one size fits all” approach  Research needs to investigate the effects of pre-exercise stretching on inflexible muscle groups  A customized corrective exercise strategy may be most effective in improving performance and decreasing the risk of injury