Chronic Pain and Manual Therapy

Chronic pain conditions (e.g., osteoarthritis, diabetic neuropathy, fibromyalgia) are not simply “long-lasting acute pain.” They reflect a multisystem dysregulation involving peripheral tissues, spinal cord processing, and brain-based modulation. This complexity helps explain why no single treatment works for everyone, why symptoms persist for years in some patients, and why long-term reliance on medications can create significant harms alongside limited sustained benefit.

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The modern view of pain: from pathway to dysregulation

Pain pathway (the “wiring diagram”)

Pain signals begin at nociceptors (Aδ and C fibres), enter the spinal cord at the dorsal horn, and ascend via tracts (e.g., spinothalamic) to the brain. The brain then interprets and modulates pain through a network including the thalamus, insula, anterior cingulate cortex (ACC), prefrontal cortex (PFC), amygdala, and brainstem centres such as the periaqueductal gray (PAG).

What changes in chronic pain

Chronic pain is marked by:

• Peripheral sensitisation: nociceptors become more excitable (ion channels influenced by cytokines, growth factors, injury).
• Spinal amplification: dorsal horn neurons show increased excitability and reduced inhibition (glutamate/NMDA up; GABA/glycine inhibition down).
• Brain network shifts: altered connectivity and neurochemistry in regions that shape the sensory and emotional/cognitive dimensions of pain.
• Descending modulation imbalance: less effective inhibition and/or more facilitation from brainstem/cortex.

Central sensitisation (a key driver)

Central sensitisation is an enduring “gain increase” in the CNS: pain is amplified, spread, and triggered more easily. It involves:

• sustained nociceptive input,
• NMDA-dependent plasticity (“wind-up”),
• reduced inhibitory tone,
• descending facilitation,
• and neuroimmune activation (microglia, inflammatory mediators).

For manual therapy, this means: tissue findings may be modest while pain and disability are high, and treatment must address both sensory input and the broader neuromodulatory context.

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Manual therapy in this landscape: what it likely does (and doesn’t)

1) Manual therapy is primarily neuromodulatory

In chronic pain, hands-on care is best understood as a sensory and regulatory intervention rather than a purely mechanical correction. Likely contributors include:

• Afferent input modulation: stimulation of cutaneous and deep mechanoreceptors changes spinal processing of nociception (gating-like effects).
• Autonomic shifts: many patients show improved parasympathetic tone and reduced stress reactivity after treatment.
• Descending inhibition support: altered brainstem–cortical control (PAG-related pathways) may increase endogenous analgesia.
• Context effects: expectation, safety, therapeutic alliance, and meaning strongly influence outcomes (not “fake”—they’re brain-mediated analgesic mechanisms).

2) Manual therapy may help “turn down the volume” of sensitisation

Evidence and theory suggest manual therapy can contribute to reducing central sensitisation by:

• providing non-threatening, graded sensory input,
• decreasing protective muscle guarding and movement avoidance,
• improving confidence and re-engagement with activity,
• and supporting sleep/stress regulation (key modulators of pain amplification).

3) Effects are often short-term unless paired with active strategies

Hands-on care frequently produces meaningful short-term relief, especially for musculoskeletal pain. Longer-term change is more likely when manual therapy is integrated with:

• progressive exercise / movement exposure
• pain education and self-efficacy strategies
• sleep and stress interventions
• and, when needed, psychological therapies (CBT/mindfulness)

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Practical implications for manual therapy practice

Mechanism-based clinical reasoning (simple version)

When chronic pain dominates, consider:

• Peripheral drivers (nociceptor sensitisation, inflammation, local tissue irritability)
• Spinal features (widespread sensitivity, disproportionate pain, allodynia)
• Brain modulation (sleep disruption, anxiety, catastrophising, trauma history, social stress)

Then match tools:

• Hands-on + calming input for sensitivity and threat reduction
• Graded movement for function and desensitisation
• Education + pacing for flare control
• CBT/mindfulness when cognitive-emotional loops maintain pain
• TENS/thermal modalities as adjuncts for symptom windows that enable movement

Dosing: think “dose-response,” not technique superiority

Across modalities, the field still struggles with standardised dosing and long-term follow-up. For manual therapy, this points to:

• explicit treatment goals (pain window vs. function),
• planned tapering,
• and progression toward self-management.

Safety and special populations

Manual therapy must be adapted in:

• older adults (bone fragility, comorbidities),
• pregnancy,
• cancer/palliative contexts,
• neuropathy with altered sensation,
• acute trauma/fracture risk.

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Key take-home

Chronic pain is a systems-level problem: sensitised peripheral inputs, amplified spinal processing, and altered brain modulation. Manual therapy can be valuable—especially as a neuromodulatory, safety-building, symptom-window intervention—but it is strongest when used to support movement, self-efficacy, and broader pain modulation, not as a stand-alone “fix.”

Shi, Y. and Wu, W., 2023. Multimodal non-invasive non-pharmacological therapies for chronic pain: mechanisms and progress. BMC medicine, 21(1), p.372.