1. Re-establishing Neuromuscular Control

2. Why is it critical to the rehabilitation process?
Refocuses the athlete’s 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.

3. 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

4. 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

5. 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

6. 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

7. 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

8. 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

9. Articular Mechanoreceptors
Quick adapting (QA)
Cease discharging shortly after onset of stimulus
Provide conscious & unconscious kinesthetic sensation in response to joint movement/acceleration
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

10. 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

11. 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
GTO’s have opposite effect of muscle spindles by producing a relaxation in the muscle being loaded

12. 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

13. 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

14. 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

15. 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 GTO’s & increase muscle spindle activity
Power trained vs. Endurance trained athletes
Power athlete = Faster muscle pre-activation (EMG)
Endurance athlete = Increased baseline motor tone

16. 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

17. 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

18. 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

19. 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

20. 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

21. 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

22. Stair climbing (forward & backward) Biofeedback
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

23. 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 8’s, cutting, carioca, changes in speed
Functional activities that simulate demands of sport

24. 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

25. Dynamic stabilization
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

26. 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