Control system - Central

Question 1

what is pain ? quotes

Answer 1

Pain is an unpleasant sensory and emotional experience associated with actual or potential damage, or described in terms of such damage”

“Pain is a multi-system output that motivates and assists the individual to get out of a situation that threatens body tissue”

Question 2

pain

Answer 2

pain is an output
it motivates
a multisystem output
Pain is not a simple input- output system

Question 3

pain key messages

Answer 3

1. We do not have pain receptors
2. Nociceptors are threat receptors
3. Pain is not “in” the tissues it is an output/
   construct of the nervous system
4. Pain is not a linear phenomenon
   • Input ≠ output
5. Pain is a multi-system phenomenon

Question 4

Motor adaptation in acute pain

Answer 4

• Motor response assists the individual to get out of a situation that threatens body tissue

Question 5

Pain and movement are intimately linked

Answer 5

• IF the brain concludes that
– danger to the body tissue exists &
– action is required
• THEN it will produce pain and a movement response to remove/ reduce the threat

Question 6

Vicious cycle theory

Answer 6

proposes a vicious cycle between pain and muscle activity.

predicts systematic increase in activity mediated by spinal mechanisms however can’t explain reduced muscle activity and Non-systematic changes

Question 7

Pain adaptation theory

Answer 7

proposes that pain causes changes in muscle activity to limit movement and protect the sensory-motor system from further injury.

Predicts systematic changes mediated by brain stem mechanisms however Cannot explain: Non-systematic changes, Non uniform inhibition of muscle, Limited to context of voluntary

Question 8

Suboptimal proprioception

Answer 8

If your nervous system doesn’t know where you are or how you are moving you cannot control movement accurately
= inaccurate input, inaccurate use of input, Different central representation and integration of input

Question 9

Implication for rehabilitation

Answer 9

Restoration of motor control may contribute to recovery of low back pain – if suboptimal loading of tissue contributes to symptoms
• This may require motor learning interventions

Question 10

pain process

Answer 10

Real or threatened nociceptive input/pain/injury >
Changes in motor behaviour (Subtle Changes in motor behaviour, Redistributed activity within & between muscles,
and Major avoidance of movement = Experience Pain cognition Pain beliefs)
> Changed motor output/mechanical behaviour:
Stiffness, force direction, load distribution, variability, force & movement amplitude
> Short term benefit:
Protection of the injured/painful region, decrease muscle activity/stress, decrease movement,e decrease potential for error

Long term consequence:
Suboptimal tissue loading

Question 11

Does the adaptation protect the painful part?

Answer 11

Leads to “protection” from further pain or injury, or threatened pain or injury

Question 12

Long term consequences

Answer 12

• Reduces movement which is important for dissipation of forces
• Reduces movement variability

Question 13

Adaptation summary

Answer 13

Pain motivates movement adaptation to reduce pain
(short term benefit)
Adaptation might persist beyond when it is necessary
Adaptation may contribute to pain persistence
(long term consequence)

Question 14

Interpretation

Answer 14

• Motor adaptation may provide short term benefit, but with long term consequences if not resolved
– Pain motivates adaptation, reduction of pain
– Adaptation might contribute to persistence of
pain
– Development of secondary issues
• Recover may require reduction of protective strategies to optimise tissue loading

Question 15

Motor adaptation in chronic pain
- Why is the threat to the body less important?
– Physiological complexities

Answer 15

•  Peripheral sensitisation 
–  Hyperalgesia
–  Allodynia
•  Central sensitisation
–  Secondary hyperalgesia
–  Allodynia
•  Ectopic pacemaker

Question 16

Motor adaptation in chronic pain
- Why is the threat to the body less important?
– Psychological complexities

Answer 16

• Attitudes and beliefs
• Distress
• Illness behaviour
• Social Environment

Question 17

Negatives

Answer 17

“Amplification” of motor adaptation beyond what is necessary
“Persistence” of motor adaptation beyond when it is necessary
“Inappropriate” motor adaptation
> Mismatch between pain & motor adaptation

Question 18

Why does pain exist?

Answer 18

combination of bio, psycho ad social factors

Question 19

changing motor control

Answer 19

If load on tissues (potentially sensitized) causes nociceptor discharge which contributes to the pain experience then it may be helpful to change motor control to optimise load on tissues

Question 20

Potential neuromuscular targets for treatment

Answer 20

• Muscle
– Reverse structural changes - atrophy & weakness, anti-
inflammatory treatment
• Neural control – SPINAL CORD
– Modify excitability of spinal motoneurons
• Differential effects likely to be required – not systematic inc/dec in activation/excitability
• Neural control – SUPRASPINAL
– Motor learning strategies
– Manage cognitive/psychosocial – pain coping skills;

Question 21

Specific motor re-education of motor control deficits

Answer 21

Optimise load on tissues – reduce nociceptive input to nervous system
• Optimise muscle activation, posture/ alignment & movement
• Individualised treatment to address features found on assessment

Question 22

Outcomes of treatment

Answer 22

• Improved structure & behaviour of deep trunk muscles
• Reduced activity of superficial trunk muscles
• Improved proprioception
  • Improved spine posture
  • Improved movement

Question 23

summary

Answer 23

• Central elements of the control system are profoundly affected by pain, injury and pathology
• Requires specific attention in rehabilitation
• Motor learning strategies are likely to be essential