Knee osteoarthritis (OA) is predominately characterized by knee pain, which can lead to impaired physical function and decreased quality of life. There is growing body of research suggesting that in a subgroup of patients with knee OA (around 30%) the clinical picture is dominated by sensitization of central nervous system pain pathways rather than by biomechanical or structural factors causing nociceptive pain.
The evidence supporting a key role for central sensitization in a subgroup of OA patients may erroneously lead clinicians to conclude that hands-on interventions have no place in the treatment of these patients, and that hands-off interventions must be applied exclusively. However, given the fact that in OA, the lasting continuous input of nociception probably directs the central sensitization, it is very important to integrate current biomechanical and pain neuroscience insights in OA in daily clinical practice. In OA treatment the balance between hands-on and hands-off treatment should be emphasized: targeting the brain without ignoring the joints (Lluch et al. 2015).
In this context, a recent study (Courtney et al. 2016) examined the effect of joint mobilization on impaired Conditioned Pain Modulation in 40 patients with moderate to severe knee OA (73% with impaired Conditioned Pain Modulation). Results showed that the joint mobilization intervention (oscillatory joint mobilization) and not the cutaneous input intervention (control intervention) resulted in a global decrease in pain sensitivity and improvement of impaired Conditioned Pain Modulation, indicating that joint mobilization may aid in facilitating central inhibitory mechanisms.
So, joint mobilization may be a useful intervention for rehabilitation of knee OA through enhancement of descending pain mechanisms. Clinically, this requires a paradigm shift in how these interventions are explained to patients, as treatment response is often described in terms of its mechanical effect. The consequences of approaching chronic pain in this specific way could be significant; patients would gain a deeper understanding of their chronic condition, and thereby greater insight into self-management.
Isabel Baert
2016 Pain in Motion
References and further reading:
Courtney CA, Steffen AD, Fernández-de-Las-Pñas C, Kim J, Chmell SJ. Joint Mobilization Enhances Mechanisms of Conditioned Pain Modulation in Individuals With Osteoarthritis of the Knee. J Orthop Sports Phys Ther. 2016 Mar;46(3):168-76.
