Regaining

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Regaining Re-establishing Neuromuscular Control
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Why is it critical to the rehabilitation process?

• Refocuses the athletes awareness of peripheral
  sensation guides them into more coordinated
  motor strategies
• Required to
• Protect joints from excessive strain
• Provide prophylactic mechanism to recurrent
  injury
• Complements traditional components of
  rehabilitation
• We rely on sensory information from the periphery
  from our visual, vestibular, somatosensory
  systems.

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• Primary role of articular structures
• Stabilize guide body segments
• Provide mechanical restraint to abnormal joint
  motion
• Dynamic restraint system
• Capsuloligamentous tissue musculotendon
  receptor sensory role
• Detect joint motion position
• Detect changes in muscle length
• Implicated in regulating muscle stiffness prior
  to loading
• Injury results in damage to microscopic nerves
  associated with peripheral mechanoreceptors
• Disrupts sensory feedback
• Alters reflexive joint stabilization
  neuromuscular coordination

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• Four critical elements of neuromuscular control
  in rehab
• Joint sensation (position, motion, force)
• Dynamic stability
• Preparatory reactive muscle characteristics
• Conscious unconscious functional motor patterns
• Rehabilitation should address feedback systems
• Preparatory (feed-forward)
• Reactive (feed-back)
• Muscle sense is divided into 4 sensory functions
• Sensation of passive movement
• Sensation of active movement
• Sensation of position
• Sensations of heaviness resistance

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What is neuromuscular control?

• Signal transmission through afferent sensory
  pathways
• Proprioception
• Conscious unconscious appreciation of joint
  position
• Awareness of position movement
• Any postural, positional or kinetic info provided
  to the CNS by sensory receptors in muscles,
  tendons or joints
• Kinesthesia
• Sensation of joint motion or acceleration
• Sensation of ACTIVE movement (contracting muscle)
• Neuromuscular control
• Efferent motor response to sensory information
• Proprioception kinesthesia

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• Motor control mechanisms
• Feed-forward neuromuscular control
• Planning movements based on sensory information
  from past experiences
• Preparatory muscle activity
• Operates on premise of initiating a motor
  response in anticipation of a load or activity
• Feed-back neuromuscular control
• Continuously regulates muscle activity through
  reflexive pathways
• Reactive muscle activity
• Operates directly in response to a potentially
  destabilizing event, using a normal reference
  point
• Muscle stiffness
• Ratio in change of force to change in length
• Stiffer muscles resist stretching more
  effective restraint to joint displacement
• Modified by muscle activation

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Activities for Inducing Adaptations

• Open closed kinetic chain activities
• Balance training
• Eccentric high repetition low load exercises
• Reflex facilitation
• Stretch-shortening
• Biofeedback training
• Controlled positions of vulnerability

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Physiology of Mechanoreceptors

• Articular Mechanoreceptors
• Specialized nerve endings that transduce
  mechanical tissue deformation into frequency
  modulated neural signals
• Increased tissue deformation results in increased
  afferent firing rate or rise in quantity of
  mechanoreceptors activated
• Types
• Pacinian corpuscles (Type II) sensitive to
  high-frequency vibration compression sensitive
• Ruffini endings (Type I) sensitive to
  stretching of the joint capsule
• Golgi-Mazzoni corpuscles (Type III) sensitive
  to joint compression, not joint motion
• Free nerve endings (Type IV) stimulated by pain
  inflammation when a joint is placed in an end
  position
• Normally not active in normal joint movement

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Articular Mechanoreceptors

• Quick adapting (QA)
• Cease discharging shortly after onset of stimulus
• Provide conscious unconscious kinesthetic
  sensation in response to joint movement/accelerati
  on
• Type II
• Slow adapting (SA)
• Continue to discharge as long as stimulus is
  present
• Continuous feedback proprioceptive information
  relative to joint position
• Type I, III

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Musculotendon Mechanoreceptors

• Muscle spindles located in the muscle
• Responds to stretch of a muscle
• Detects length rate of length changes
• Its stimulation leads to a contraction
• Transmit information via afferent nerves
• Innervated by small motor fibers (gamma
  efferents)
• Project directly on motoneurons (monosynaptic
  reflexes)
• Stretch reflex
• Stimulation results in reflex contraction
• Continued stimulation (gamma motor nerves)
  heighten stretch sensitivity
• Muscle activity mediation

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Musculotendon Mechanoreceptors

• Golgi Tendon Organs (GTO) located in tendon
  musculotendon junction
• Detects tension within a muscle responds to
  both the contraction stretching of a muscle
• Regulate muscle activity tension
• Its stimulation results in muscle relaxation
• GTOs have opposite effect of muscle spindles by
  producing a relaxation in the muscle being loaded

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Neural Pathways of Peripheral Afferents

• Encoded signals - transmitted from peripheral
  receptors via afferent pathways (interneurons) to
  CNS
• Brain Stem Balance
• Primary proprioceptive correlation center
• Cerebral Cortex location of conscious movement
• Monosynaptic reflex pathway - links muscle
  spindles directly to motor nerves
• Balance
• Influenced by peripheral afferent mechanism
  mediating joint proprioception
• Partially dependent on inherent ability to
  integrate joint position sense, vision
  vestibular apparatus with neuromuscular control

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• Interneurons
• Connect articular receptors GTO with large
  motor nerves innervating muscles small gamma
  motor nerves innervating muscle spindles
• Articular afferents have potent effect on muscle
  spindles
• Muscle spindles regulate muscle activity through
  stretch reflex
• Hence, articular afferents have influence on
  skeletal motor nerves tenomuscular receptors
  via gamma motor nerves
• Reflex Loop
• Spinal Level Synapses
• Link afferent fibers with efferent motor nerves
• Contributes to dynamic stability utilizing
  feedback process for reactive muscular activation

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Feed-Forward Feedback Neuromuscular Control

• Feed-forward Neuromuscular control
• Pre-activation theory
• Prior sensory feedback (experience) is utilized
  to pre-program muscle activation patterns
• Responsible for preparatory muscle action high
  velocity movements
• Increased muscle activation enhanced stiffness
  properties
• Leads to improvement in stretch sensitivity
  reduces electromechanical delay
• Improves reactive capabilities (added sensory
  input superimposed stretch reflexes on
  descending motor command

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Muscle Stiffness Influence
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• Feedback Neuromuscular Control
• Continuously adjusting muscle activity via reflex
  pathways
• May result in long conduction delays
• Best for postural adjustments slow movements
• Reflex mediated dynamic stability is related to
  speed magnitude of perturbation
• Both systems enhance dynamic stability
• Repetitive activation of synapses facilitation
• Memory recall of signal enhanced function

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Re-establishing Neuromuscular Control

• Injuries result in decreases in neuromuscular
  control
• Pathoetiology
• Injury results in deafferentation of ligament
  capsular mechanoreceptors
• Joint inflammation pain compound sensory
  deficits
• Congenital/pathological joint laxity have
  diminished ability to detect joint motion
  position
• Proprioceptive, kinesthetic deficits mechanical
  instability lead to functional instability

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• Objectives for Neuromuscular Rehabilitation
• Develop/re-establish afferent efferent
  characteristics that enhance dynamic stability
• Elements
• Proprioceptive kinesthetic sensation
• Dynamic joint stabilization
• Reactive neuromuscular control
• Functional motor patterns
• Afferent Efferent Characteristics
• Sensitivity of peripheral receptors
• Facilitation of afferent pathways
• Muscle stiffness
• Onset rate magnitude of muscle activity
• Simultaneous activation of agonist/antagonist
• Reflexive discriminatory muscle activation

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Neuromuscular Characteristics

• Peripheral Afferent Receptors
• Altered peripheral afferent information may
  disrupt motor control functional stability
• Repetitious athletic activity enhances
  proprioceptive kinesthetic acuity
  facilitated afferent pathways
• Enhanced joint motion awareness improves
  feed-forward feedback mechanisms
• Muscle Stiffness
• Significant role in preparatory reactive
  dynamic restraints
• Exercises that encourage muscle stiffness should
  be incorporated into rehabilitation programs
• Eccentric exercises
• Chronic overload results in connective tissue
  proliferation, desensitizing GTOs increase
  muscle spindle activity
• Power trained vs. Endurance trained athletes
• Power athlete Faster muscle pre-activation
  (EMG)
• Endurance athlete Increased baseline motor tone

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• Reflexive Muscle Activation
• Reflex latency times may be dependent on types of
  training (endurance vs. power)
• Preparatory reactive muscle activation might
  improve dynamic stability function if muscle
  stiffness is enhanced in deficient joints
• Decreasing electromechanical delay between joint
  loading protective muscle activation can
  increase stability function

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• Discriminate Muscle Activation
• Unconscious control of muscle activity is
  critical in balance coordination
• May initially require conscious activation prior
  to unconscious control
• Use of biofeedback can aid in this process
• Help eliminate imbalances re-establish
  preparatory reactive muscle activity

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Elements for Neuromuscular Control

• Proprioception Kinesthesia Training
• Restore neurosensory properties
• Enhance sensitivity of uninvolved peripheral
  afferents
• Joint compression is believed to maximally
  stimulate articular receptors
• Closed chain exercises through available ROM
• Early repositioning tasks are critical
• Conscious to unconscious joint awareness
• Applying neoprene sleeve or ace wrap stimulates
  cutaneous receptors additional proprioception
  kinesthesia

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• Dynamic Stabilization
• Encourage preparatory agonist/antagonist
  coactivation
• Restores force couples balances joint forces
• Results in decreased loads on static structures
• Activities that require anticipatory reactive
  adjustments to imposed loads
• Combination of balance stretch shortening
  exercises
• Encourages preparatory reactive muscle activity
• Closed chain exercises induce coactivation
  compression

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• Reactive Neuromuscular Control
• Stimulates reflex pathways
• Object is to impose perturbations that stimulate
  reflex stabilization
• Can result in decreased response time develop
  reactive strategies to unexpected joint loads
• Perturbations should be unexpected in order to
  facilitate reflexive activity
• Functional Activities
• Objective is to return athlete to pre-injury
  activity
• Involves sports specific movement patterns
  designed to restore functional ability
• Can be utilized to assess readiness for return to
  play
• Stresses peripheral afferents, simultaneous
  muscle activation, reflexive activity
• Progress from conscious to unconscious
• Develop functionally specific movement patterns,
  ultimately decreasing risk of injury

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Lower Extremity Techniques

• Techniques should focus on muscle groups that
  require attention
• Progress from no weight to weight assisted
• Use of closed-chain activities is encouraged
• Replicates environmental demands
• Plays on principles of neuromuscular control
• Joint stabilization exercises
• Balance partial weight bearing activities
• Progress non-weight bearing to full
  weight-bearing
• Balance on unstable surfaces can begin once
  full-weight bearing

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• Slide board exercises
• Stimulates coactivation with increasing muscle
  force endurance
• Stimulating dynamic stability stiffness
• Stair climbing (forward backward)
• Emphasis on eccentric strength
• Biofeedback
• Used to develop agonist/antagonist coactivation
• Encourages voluntary muscle activation
• Stretch-shortening exercises
• Eccentric deceleration explosive concentric
  contractions
• Incorporate early in process (modified loads)
• Involves preparatory reactive muscle activity
• Hopping progression
• Double ? Single leg
• Sagittal ? Lateral ? Rotational hopping
• Surface modification

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• Rhythmic stabilization
• React to joint perturbations ?preparatory
  reactive muscle activity
• Alterations in loads displacement
• Unstable surfaces
• Linear angular perturbations, altering center
  of gravity
• Facilitate reflexive activity
• Ball toss
• Disrupt concentration, induce unconscious
  response reactive adaptation

• Trampoline Hopping
• Hopping landing (double support, single
  support, rotation)
• Challenge athlete
• Hopping catching
• Hopping landing on varying surfaces
• Functional activities
• Restore normal gait
• Athlete must internalize normal kinematics (swing
  stance)
• Utilize retro walking (hamstring activity), pool
  or unloading devices
• Cross over walking, figure 8s, cutting, carioca,
  changes in speed
• Functional activities that simulate demands of
  sport

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Upper Extremity Techniques

• Work to maintain joint congruency functional
  stability
• Requires dynamic restraint via coordinated muscle
  activation
• Injury to static stabilizers
• Failure of dynamic restraint system
• Could result in repetitive loads, compromising
  joint integrity predisposing athlete to
  re-injury
• Adapt lower extremity exercise for upper extremity

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• Muscle stiffness
• Enhance using elastic resistance (focus on
  eccentrics)
• High repetitions low resistance
• Upper extremity ergometers should be incorporated
  for endurance
• Dynamic stabilization
• Stability platforms
• Push-ups, horizontal abduction, tracing circles
  on slide board with dominant non-dominant arms
• Plyometric exercise

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• Reactive Neuromuscular Exercises
• Manual perturbations
• Rhythmic stabilization with gradual progression
• Placing joint in inherently unstable positions
• Functional Training
• Developing motor patterns in overhead position
• Reproduce demands of activity
• Emphasis on technique
• Re-education of functional patterns
• Speed complexity in movement require rapid
  integration of sensory information

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References

• www.google.com
• Images
• Prentice, W.E. (2004). Rehabilitation Techniques
  for Sports Medicine Athletic Training, 4th
  edition, McGraw-Hill software