Pain Neurophysiology and Movement

Key Concepts

1. Nociceptive Pathways

• • • Nociception and nociceptors: The process of detecting harmful stimuli and generating a sensory signal to the spinal cord through specialised sensory nerves called nociceptors
    • Transmission: Once activated, nociceptors transmit sensory signals via A-delta fibres (sharp precise pain response) and C fibres (dull diffuse pain response) to the spinal cord
    • Spinal Processing: In the spinal cord, signals can be modified by either inhibiting (stopping) or facilitation (upregulating) sensory signals
    • Ascending Pathways: nociceptive signals travel through assigned pathways to the main terminal (thalamus) and then to many regions of the brain for processing

2. Pain Perception

• • • The brain integrates nociceptive sensory input with emotional and cognitive factors, leading to the subjective and individual experience of pain
    • Factors such as prior experiences, environment, mood, and context can significantly influence how sensory information is processed by the brain to produce what it perceives to be the appropriate pain response

3. Persistent Pain

• • • After tissue trauma the peripheral nervous system is sensitised, and this can lead to increased central sensitivity (central sensitisation) – both these factors can cause nociception and pain in the absence of harmful stimuli
    • This produces structural and functional changes in the spinal cord and brain (neuroplasticity) that can remain after tissues heal and pain is produced when it is not needed – the brain perceives there is a threat to tissue when no threat exists

Movement and Pain

1. Pain and Motor Function:

• • • Pain often leads to altered movement patterns as the brain subconsciously protects the affected area creating muscle imbalances, dysfunction and pain
    • Fear of pain can also restrict movement, leading to decreased physical activity and physical deconditioning

2. Rehabilitation:

• • • Effective rehabilitation focuses on restoring movement through graded exposure to activities, addressing both the physical and psychological aspects of pain
    • Physical therapy, psychological therapy, mindfulness, and cognitive diffusion techniques can help alter irrational beliefs and perceptions to manage pain and improve function

3. Positive Neuroplasticity:

• • • The nervous system’s ability to adapt can be harnessed via physical and cognitive rehabilitation
    • Positive movement experiences can help retrain the nervous system and brain and reduce sensitisation – this can decrease a heightened level of threat to body tissues perceived by the brain