Musculoskeletal pain and exercise, challenging existing paradigms and introducing new

Key points

1. 01Exercise is the cornerstone of managing chronic musculoskeletal pain, but the exact reasons it helps are still unclear and effect sizes stay small to modest.
2. 02The review challenges the long-held rule that pain must always be avoided, shifting from a tissue-damage model toward a biopsychosocial model of pain.
3. 03It proposes three mechanisms by which painful exercise might help: reducing pain-related fear and threat in the brain, boosting the body's own pain-dampening systems, and calming the immune and stress response.
4. 04Allowing painful exercise paired with safety messages may build new 'safe' associations that compete with old fear-based pain memories.
5. 05The authors are explicit that the ideas rest on preliminary data and that many mechanisms are shared by painful and pain-free exercise.

How it was conducted

Design

Narrative, non-systematic review of current understanding and proposed mechanisms

Topic

Mechanisms behind therapeutic exercise for chronic musculoskeletal pain, and the theoretical added benefit of allowing painful over pain-free exercise

Mechanisms examined

Central and peripheral pain sensitisation, the immune system, and affective (fear-related) aspects of pain

Aim

To explain potential mechanisms behind exercise and build a theoretical rationale for allowing painful exercises

What they found

• A cited meta-analysis of 7 randomised controlled trials found protocols allowing painful exercises gave a small but statistically significant short-term benefit over pain-free exercises.
• A cited self-management review (16 studies; n=4047) identified self-efficacy and depression as the strongest prognostic factors, and reduced pain catastrophising plus increased physical activity as the strongest mediating factors.
• The authors report that current evidence shows only a modest difference in efficacy between painful and pain-free exercise.
• Cited human studies on military personnel found that those with PTSD had decreased activation of the medial prefrontal cortex with correlated increased activation of the amygdala, supporting an inverse relationship used to explain fear-extinction learning.

Limitations

• The authors state this is a narrative, non-systematic review describing concepts supported only by preliminary data.
• Many of the proposed mechanisms apply equally to painful and pain-free exercise, and current evidence shows only a modest difference in efficacy.
• Much of the supporting mechanistic evidence comes from animal studies, experimental pain models, and conditions such as PTSD rather than direct clinical trials of painful exercise.
• Exact mechanisms underpinning the effect of exercise on musculoskeletal pain remain unclear, and there is a lack of evidence supporting any specific exercise intervention.

Why it matters

For patients

If you have long-standing muscle or joint pain, some pain during prescribed exercise is generally not a sign of harm, and continuing to move with guidance may help, though you should keep the pain to a level you can cope with.

For clinicians

Consider framing exercise with safety cues, fear reconceptualisation, and self-efficacy building rather than insisting on strictly pain-free movement, while recognising the added benefit over pain-free exercise is modest and mechanistically theoretical.

For readers

This piece reframes the 'no pain' rule around chronic pain using brain and immune-system science, but it is a hypothesis-generating review, not proof that painful exercise is clearly superior.