Exercise therapy for chronic musculoskeletal pain: Innovation by altering pain memories

Abstract

Even though nociceptive pathology has often long subsided, the brain of patients with chronic musculoskeletal pain has typically acquired a protective (movement-related) pain memory. Exercise therapy for patients with chronic musculoskeletal pain is often hampered by such pain memories. Here the authors explain how musculoskeletal therapists can alter pain memories in patients with chronic musculoskeletal pain, by integrating pain neuroscience education with exercise interventions. The latter includes applying graded exposure in vivo principles during exercise therapy, for targeting the brain circuitries orchestrated by the amygdala (the memory of fear centre in the brain).

Before initiating exercise therapy, a preparatory phase of intensive pain neuroscience education is required. Next, exercise therapy can address movement-related pain memories by applying the ‘exposure without danger’ principle. By addressing patients' perceptions about exercises, therapists should try to decrease the anticipated danger (threat level) of the exercises by challenging the nature of, and reasoning behind their fears, assuring the safety of the exercises, and increasing confidence in a successful accomplishment of the exercise. This way, exercise therapy accounts for the current understanding of pain neuroscience, including the mechanisms of central sensitization.

Introduction

In acute musculoskeletal pain, the main focus for treatment is to reduce the nociceptive trigger. Such a focus on peripheral pain generators is often effective for treatment of (sub)acute musculoskeletal pain (Surenkok et al., 2009, Grunnesjo et al., 2011, Brantingham et al., 2013, Struyf et al., 2013). In patients with chronic musculoskeletal pain, ongoing nociception rarely dominates the clinical picture. Chronic musculoskeletal pain conditions including osteoarthritis (Lluch Girbes et al., 2013), rheumatoid arthritis (Meeus et al., 2012), whiplash (Curatolo et al., 2001, Banic et al., 2004, Sterling, 2010), fibromyalgia (Staud, 2002, Meeus and Nijs, 2007), low back pain (Roussel et al., 2013), pelvic pain (Kaya et al., 2013) and lateral epicondylitis (Fernandez-Carnero et al., 2009), are often characterized by brain plasticity that leads to hyperexcitability of the central nervous system (central sensitization). Growing evidence supports the clinical importance of central sensitization in patients with chronic musculoskeletal pain (Sterling et al., 2003, Jull et al., 2007, Coombes et al., 2012, Smart et al., 2012).

In such cases, musculoskeletal therapists need to think and treat beyond muscles and joints (Nijs et al., 2013). Within the context of the management of chronic pain, it is crucial to consider the concept of central pain mechanisms including central sensitization (Gifford and Butler, 1997). Modern pain neuroscience calls for treatment strategies aimed at decreasing the sensitivity of the central nervous system (i.e. desensitizing therapies).

Treatments capable of desensitizing the central nervous system in patients with chronic pain have been proposed, including exercise prescription (Mease et al., 2011, Woolf, 2011, Nijs et al., 2011a, Lluch Girbes et al., 2013), but up to now exercise therapy as a potential desensitizing treatment (Nijs et al., 2012) for chronic musculoskeletal pain has not been adequately addressed. Here it is explained how musculoskeletal therapists can integrate pain neuroscience education (Butler and Moseley, 2003, Nijs et al., 2011b) with exercise interventions, and how they can apply graded exposure in vivo principles (Vlaeyen et al., 2012) during exercise therapy for patients with chronic musculoskeletal pain. Together, the treatment proposed here aims at altering pain memories in patients with chronic musculoskeletal pain.