Should exercise be painful?

When assisting a patient with rehabilitation from injury or pain, a major question that needs to be asked is "should this patient exercise through pain or not?" This becomes even more pertinent if the patient's condition consists of primary pain (1). And there have certainly been arguments for both sides on this topic (2-4) as pain management has been emerging as an increasingly relevant matter in current medicine.

Most practitioners realise that that there cannot be a "blanket rule" that can be applied to all, but every patient is an opportunity for a practitioner to clinically apply biopsychosocial framework followed by a construction of case formulation (5, 6). Thus the decision to exercise through pain or not is usually a destination that a practitioner can naturally arrive after such preceding thought-processes.

There are four important factors to consider when deciding whether or not a patient should exercise “through pain”:

 

1) Pathophysiology of the current condition
2) Mechanism of the pain being experienced
3) Patient’s attitude and beliefs
4) Level of endogenous modulation

 

1) Pathophysiology of the current condition

Perhaps the most obvious one; certain pathophysiological states logically indicate that exercising in pain would not be a sensible choice: e.g. acute inflammation post traumatic injury with tissue disruption. However some conditions are not as clear-cut: e.g. chronic patellofemoral pain. In such instances critical analysis of the diagnosis would be necessary before a decision is made: if a clinician was to reason that such patellofemoral condition was a result of muscle dysfunction from pain inhibition (7), it may be more reasonable to exercise without pain as further pain is likely to reinforce inhibition, especially in the early stages.

2) Mechanism of the pain being experienced

"Mechanism-specific approach" classifies pain into four categories (8, 9): nociceptive, inflammatory, neuropathic and dysfunctional (or nociplastic). While there are no “hard-guidelines” that can clearly define a given pain into such categories, it is not difficult to make a hypothetical call after a thorough case formulation construction, and such approach is absolutely necessary to provide a foundation of care for complex multi-dimensional conditions such as primary pain. Once mechanism of pain is hypothetically determined, the implication of experiencing such pain while exercising becomes clearer; e.g. certain nociceptive pain may be ignored, or even beneficial, whereas inflammatory and neuropathic pain is generally best to be avoided. Dysfunctional / nociplastic pain will need to be deconstructed - i.e. cause of the pain analysed - before determining the possible effects of experiencing such pain while exercising.

3) Attitude and beliefs

Pain excitation or inhibition from cortical and subcortical centres are well-documented through literature (10-12) and anecdotes, and the main constructs behind this powerful process are the attitude and beliefs of the patient. This is where fear-avoidance and catastrophising exist at one extreme, and placebo response and attentional modulation at the other. How a clinician positively “manipulates” these is critical to the success of the rehabilitation and is often dependent upon the “art” of communication and persuasion skills. Graded exposure (13, 14) is one of the most important and widely-used cognitive framework on which exercise therapy can be effectively integrated.

4) Suspected level of endogenous modulation

This resides closely to “attitudes and beliefs” as their end-effect is also endogenous modulation. However there are many other factors that can influence endogenous modulation (e.g. genetic, DNIC, autonomic regulation, gender, age, fitness, physical and psychological history) and these are important data that need to be considered to hypothetically assess the “activity level” of patients' endogenous pain modulation. In essence, stronger the modulation is suspected, stronger the exercise stimulation may be, and possibility of exercising through pain.

It is critical to specify the intention or aim behind exercise programmes when prescribing to patients as this will often give a quick indication of how the experience of pain should be handled. For example, in a case of mobilisation of joints and soft tissues post fracture with no significant pain issues, it is probably useful to “stretch into the pain zone" if this coincides with the restriction in range of motion and evidence of tissue shortening (i.e. nociceptive pain).

Compared to this in management of primary pain the goals are, in most cases, to modulate pain and facilitate neural recruitment. Thus how a clinician teaches patients to handle pain when it inevitably occurs during exercises - whether to alter exercises to minimise pain or to "ignore and keep going" - will need to be carefully considered in accordance with abovementioned factors to ensure the best outcome.

References

1. Treede RD, Rief W, Barke A, Aziz Q, Bennett MI, Benoliel R, et al. A classification of chronic pain for ICD-11. Pain. 2015;156(6):1003-7.

2. Booth J, Moseley GL, Schiltenwolf M, Cashin A, Davies M, Hubscher M. Exercise for chronic musculoskeletal pain: A biopsychosocial approach. Musculoskeletal Care. 2017.

3. Daenen L, Varkey E, Kellmann M, Nijs J. Exercise, not to exercise, or how to exercise in patients with chronic pain? Applying science to practice. Clin J Pain. 2015;31(2):108-14.

4. Smith BE, Hendrick P, Smith TO, Bateman M, Moffatt F, Rathleff MS, et al. Should exercises be painful in the management of chronic musculoskeletal pain? A systematic review and meta-analysis. Br J Sports Med. 2017.

5. Eells TD, Kendjelic EM, Lucas CP. What's in a Case Formulation? Development and use of a Content Coding Manual. Journal of Psychotherapy Practice and Research. 1998;7(2):144-53.

6. Linton SJ, Nicholas MK. After assessment, then what? Integrated findings for successful case formulation and treatment tailoring. In: Breivik H, Campbell WI, Nicholas MK, editors. Clinical Pain Management: Practice and Procedures. 2nd ed: CRC Press; 2008. p. 95-106.

7. Mense S. Muscle pain: mechanisms and clinical significance. Dtsch Arztebl Int. 2008;105(12):214-9.

8. Vardeh D, Mannion RJ, Woolf CJ. Toward a Mechanism-Based Approach to Pain Diagnosis. J Pain. 2016;17(9 Suppl):T50-69.

9. Woolf CJ. Pain: Moving from Symptom Control toward Mechanism-Specific Pharmacologic Management. Annals of Internal Medicine. 2004;140:441-51.

10. Goffaux P, Redmond WJ, Rainville P, Marchand S. Descending analgesia--when the spine echoes what the brain expects. Pain. 2007;130(1-2):137-43.

11. Kenntner-Mabiala R, Andreatta M, Wieser MJ, Muhlberger A, Pauli P. Distinct effects of attention and affect on pain perception and somatosensory evoked potentials. Biol Psychol. 2008;78(1):114-22.

12. Wiech K, Ploner M, Tracey I. Neurocognitive aspects of pain perception. Trends Cogn Sci. 2008;12(8):306-13.

13. de Jong JR, Vlaeyen JW, Onghena P, Goossens ME, Geilen M, Mulder H. Fear of Movement/(Re)injury in Chronic Low Back Pain. Education or Exposure In Vivo as Mediator to Fear Reduction? The Clinical Journal of Pain. 2005;21:9-17.

14. Vlaeyen JW, de Jong JR, Geilen M, Heuts PHTG, van Breukelen G. The Treatment of Fear of Movement/(Re)injury in Chronic Low Back Pain: Further Evidence on the Effectiveness of Exposure In Vivo. The Clinical Journal of Pain. 2002;18:251-61.