Control system - Central Flashcards
what is pain ? quotes
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”
pain
pain is an output
it motivates
a multisystem output
Pain is not a simple input- output system
pain key messages
- We do not have pain receptors
- Nociceptors are threat receptors
- Pain is not “in” the tissues it is an output/
construct of the nervous system - Pain is not a linear phenomenon
• Input ≠ output - Pain is a multi-system phenomenon
Motor adaptation in acute pain
• Motor response assists the individual to get out of a situation that threatens body tissue
Pain and movement are intimately linked
• 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
Vicious cycle theory
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
Pain adaptation theory
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
Suboptimal proprioception
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
Implication for rehabilitation
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
pain process
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
Does the adaptation protect the painful part?
Leads to “protection” from further pain or injury, or threatened pain or injury
Long term consequences
- Reduces movement which is important for dissipation of forces
- Reduces movement variability
Adaptation summary
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)
Interpretation
• 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
Motor adaptation in chronic pain
- Why is the threat to the body less important?
– Physiological complexities
• Peripheral sensitisation – Hyperalgesia – Allodynia • Central sensitisation – Secondary hyperalgesia – Allodynia • Ectopic pacemaker
