Effect of exercise on chronic neck pain and central sensitization: A protocol for a randomized crossover trial

Abstract

Exercise-induced hypoalgesia (EIH) has been found to vary widely within individuals with chronic neck pain (NP). Research has suggested that the presence of central sensitization within a subgroup of individuals with chronic NP might be a mediating factor to explain the relationship between exercise and improvements in patient-reported outcomes. Furthermore, recent work has found that lactate might play a role in the development and maintenance of chronic pain. The immediate effect of a single bout of physical exercise on central sensitization in individuals with chronic NP and the relationship between lactate concentration, central sensitization and pain sensitivity are to be investigated. Eighty adult participants with chronic NP will be recruited for this randomized crossover trial. Outcome measures, including temporal summation, conditioned pain modulation, EIH and lactate concentration, will be assessed before and after low- and high-intensity bicycling exercise. The outcomes of this study will provide new insights into the mechanistic effect of exercise on central sensitization in individuals with chronic NP and have the potential to add important information to the current exercise prescription guidelines for individuals with chronic NP. This study has been approved by the Human Research Ethics Committee, The University of Adelaide (H-2022-082) and registered in the Australian New Zealand Clinical Trials Registry (ACTRN12622000642785p).

Keywords: central sensitization; chronic pain; exercise therapy; neck pain; physical exercise.

FIGURE 1

Schedule of enrolment, interventions and assessments. Abbreviations: CPM, conditioned pain modulation; EIH, exercise‐induced hypoalgesia; GPAQ, global physical activity questionnaire; NDI, neck disability index; PCS, pain catastrophizing scale; SF‐36, 36‐item short form survey; ‐t₁, enrolment week 0; t₀, allocation; t_1–2, intervention, baseline and post‐intervention assessments; TS, temporal summation; TSK, Tampa scale of kinesiophobia.

FIGURE 2

Flowchart of study procedure and the associated assessment conducted.

FIGURE 3

Assessment flowchart at each data collection session. Abbreviations: CPM, conditioned pain modulation assessment; CPT, cold pain threshold; EIH, exercise‐induce hypoalgesia assessment; [La], blood lactate concentration assessment; PPT, pain pressure threshold; TS, temporal summation assessment.