Motor control and pain 1

Question 1

Original pain/motor theory 1- Vicious cycle theory

Answer 1

• Pain-spasm-pain cycle
• Pain causes increase in stereotypical muscle activity
• Limits movement
• Sustained activity&raquo_space; ischemia
• = more pain

Question 2

Original pain/motor theory 2- Pain adaption theory

Answer 2

•	Pain causes reduction in muscle activity of agonists
•	Increase in agonist muscle activity
•	= reduction in:
o	Force production
o	Range
o	Velocity of movement

Question 3

4 newer theories for pain/motor control

Answer 3

1. Sub-optimal movement/loading- precursor for injury/pain
2. Impaired movement- consequence of interference by pain/injury (injury/pain interference hypothesis)
3. Modified movement- product of a conditioned response to pain (conditioned response hypothesis)
4. Modified movement- for protection of area (protective response hypothesis)

Question 4

Suboptimal loading

Answer 4

• Hypothesis- suboptimal loading excites nociceptive afferents (+/- tissue injury) = pain
• i.e. movements/positions cause pain
• single event
• accumulated load

Question 5

Pain/injury interference

Answer 5

• Noci and non-noci afferent input may directly influence motor neuron excitability
• i.e. pain and injury cause motor control change
• inhib or excitatory response
• variable/situation dependent response
• usually protective
• E.g. arthrogenic inhibition- muscles across injured joints are inhibited

Question 6

Conditioned response hypothesis

Answer 6

• Individual may learn to associate a movement with pain through classical conditioning
• Movement may initially activate noci pathways
• After while pain may be experienced in association with movement despite absence of noci involvement
• Result: innocuous stim = pain, anticipatory fear or increased muscle tension

Question 7

Treatment for sub-optimal loading

Answer 7

• Optimise loading strategy/ find solution to load

* Specific or generic skill learning

Question 8

Treatment for pain/injury interference

Answer 8

• Counteract the consequences of interference
• May be necessary to treat:
o The stimulus of the effect (e.g. joint swelling)
o Outcome of interference (e.g. reflex inhibition)
o Or both

Question 9

Treatment for conditioned response

Answer 9

• Extinguish conditioned response
• Aim to help patient experience pain free movement
o Exercise/education
o Virtual movement