Summary of Neurophysiological Principles

Question 1

Summary of Neurophysiological Principles

Answer 1

After Discharge
• Temporal Summation
• Spatial Summation
• Irradiation
• Successive Induction
• Reciprocal Innervation (Inhibition)
• Autogenic Inhibition

Question 2

After discharge:

Answer 2

• Any somatosensory stimulation (touch, pressure, proprioception) has a continuation of the stimulus after cessation of stimulation.
• The greater the stimulus, the greater the discharge.

Question 3

Temporal Summation:

Answer 3

• Repeated stimuli (generally weaker)
• Occurring within a short period of time
• Combine to cause excitation
(CONTINOUSLY STABBING SOMEONE AT SAME SPOT)

Question 4

Spatial Summation:

Answer 4

DIFFERENT SPACES/LOCATIONS AT SAME TIME
• Weak stimuli applied to different areas of the body simultaneously.
• Reinforces the facilitatory effect to cause excitation.

Question 5

Irradiation:

Answer 5

• Spreading of the response>overflow from stronger muscle groups to weaker muscle groups.
• Increased strength of the response.
• Increased number of stimuli OR Increased intensity of stimulus.
* HAVE STRONGER MUSCLES HELP WITH RECRUITMENT

Question 6

Successive Induction:

Answer 6

• Strong contraction of the antagonist muscle (muscles opposing the action) causes reciprocal inhibition of the agonist (muscles contributing to the desired direction of movement).
• Once the antagonist relaxes, the inhibition ceases and there is an increased excitation of the agonist.

Question 7

Reciprocal Innervation (Inhibition):

Answer 7

• Contraction of muscles leads to simultaneous relaxation (inhibition) of their antagonists.
Example - Reciprocal inhibition in stretch reflex:
• Joints are controlled by opposing muscle groups (flexors / extensors).
• When a muscle spindle stretches and activates the stretch reflex, the opposing muscle group needs to be inhibited so that it doesn’t work against the contraction of the desired muscle.
• Remember muscle spindles lie within the muscle belly and respond to stretch (changes in muscle length).

Question 8

Autogenic Inhibition:

Answer 8

• Reflex relaxation that will occur in the same muscle that the Golgi tendon organ is stimulated in (this occurs by isometrically contracting a stretched muscle)a - Lowers resistance to stretch therefore can increase ROM.
• Remember, GTO are located in muscle tendons and respond to force / muscle tension.

Question 9

TECHNIQUES

Answer 9

Facilitatory – used to gain muscle activity Example: Mm strength, mm endurance, coordination
Inhibitory – used to reduce muscle activity Example: Increase range, decrease tone

Question 10

PNF TECHNIQUES

Answer 10

• Methods by which the patterns of movement are applied to achieve various responses.
• PNF uses concentric, eccentric and isometric muscle contractions combined with suitable resistance and specific facilitatory techniques.
• Examples:
– Use facilitation to increase strength and / or stability.
– Use inhibition combined with facilitation to increase range.
• Treatment goals can include:
– Increase ROM
– Increase strength
– Develop co-ordination
– Reduce fatigue
– Decrease pain

Question 11

Facilitation

Answer 11

• Utilise facilitatory neurophysiological principles – after discharge, temporal and spatial summation, irradiation, successive induction
• Physiotherapists can utilise facilitation techniques to make movement easier and more accurate for patients.
• The accuracy in movement is imperative in prevention of musculoskeletal injuries, and also vital for efficient functioning.
• Treatment methods / approaches that use facilitation methods include PNF (Kabat, Knott & Voss), Bobaths, Rood, Ayres and Sahrmann.

Question 12

When is facilitation appropriate?

Answer 12

If you are trying to get a muscle contraction when it is difficult for the patient to contract the muscle due to:
– Weakness – Pain
– CNS damage
– Abnormal recruitment patterns

Question 13

Facilitation Specific Techniques

Answer 13

• Rythmic initiations
• Slow reversals
• Slow reversals hold
• Repeated contractions
• Rhythmic stabilisations
(Listed in order of typical progressions)

Question 14

Rhythmic Initiation

Answer 14

• Assists patient to initiate movement (e.g. apraxic patient)
• ALWAYS start with this to ensure the patient understands the movement and is performing correctly.
• Improves co-ordination and sense of motion
• Normalizes the rate of motion
• Teaches the motion
• Can help the patient relax
• Can classify as a ‘strengthening’ exercise in very low level patients

Question 15

Rhythmic Initiation

Application:

Answer 15

• Passively move the limb / part through full available range in the PNF pattern.
• Patient watches / concentrates on feeling the movement.
• Ask the patient to assist your movement (or may ask them to do it themselves if strong enough) to ensure they have understood.
• Progression > Slow reversals.

Question 16

Slow Reversals

Answer 16

• Can be used for improving muscular strength
• Can be used for improving muscular endurance
• Can be used to facilitate normal timing between agonists and antagonists.
• Example = Useinpatientswithmuscleweakness.

Question 17

Slow Reversals Application:

Answer 17

• If you have gone through rhythmic initiation and the patient is tolerating ok,
then you can add resistance to the agonist and antagonist patterns through full available range > this becomes a slow reversal technique
• Start in direction of pattern with weaker muscle groups (isotonic contraction of agonists)
• Smoothly reverse into antagonist pattern (isotonic contraction of antagonists). Repeat.
• MAXIMISE all sensory inputs – voice, touch, visual cues
• Progression > Slow reversal holds

Question 18

Slow Reversals Hold

Answer 18

• Used to increase the motor unit recruitment and strength at a particular point in the motion
• Might add/progress to repeated contraction application to enhance the HOLD
Application:
• An isometric hold is applied at any point in the execution of a diagonal pattern of movement where muscle response is less / weaker.

Question 19

Repeated Contractions

Answer 19

• Enhances recruitment of motor units.
• Used mainly when muscle WEAKNESS is a problem or when initiation of movement is difficult.
Advantages:
• Learning and skill acquisition occurs through repeated stimulus of CNS: o Allows focus to specific muscle / group of muscles.
o Uses repeated stretch of muscle spindle to recruit motor units. o Focus on voluntary contraction response.
• Enables increased strength / endurance in very weak muscles.
• When fatigue of muscle response is evident, you MUST stop and allow recovery.

Question 20

Repeated Contractions

Application:

Answer 20

Move out of the agonist pattern a short amount (+stretch stimulus) à initiate command to move into agonist pattern again
Commands:
• Now PULL (apply stretch and resist flexion)
• Or now PUSH (apply stretch and resist extension)

Question 21

Rhythmic Stabilisations

Answer 21

• Used to gain stability and increase endurance.
Example = In a patient with poor globa land/or local stability.
• Aims to gain isometric contraction of agonists and antagonists to provide joint/s stability.
• Particularly useful if there is PAIN when motion is attempted.
• Prescription guideline: 10 x 10 second holds

Question 22

Rhythmic Stabilisations APPLICATION:

Answer 22

• Get the patient to perform an isometric contraction of the agonist/s.
• Following this, get the patient to perform an isometric contraction of the antagonist/s.
• Do NOT apply too much resistance – contraction is isometric & aims for co- contraction.

Question 23

PNF AIMS

Answer 23

PNF aims to combine the many facilitatory factors such as sight, hearing, touch, pressure and resistance to give a bigger sensory demand and so a bigger motor response is elicited.