Feasibility of Pain Informed Movement for Knee OA

Overview

The pain experience and its associated mechanisms in people with knee osteoarthritis (OA) are known to be complex and multidimensional. The current understanding of OA pain mechanisms is incomplete, resulting in limited pain management strategies. There is high-quality evidence that suggests the use of exercise for people with knee OA can provide a reduction in pain, changes in quality of life, and have modest improvements in physical function. There is promising evidence to support that yoga for those with knee OA may improve pain intensity, function, and stiffness. The aim of this study is to establish the feasibility of a pain informed movement program, in addition to education for improving pain modulation. The data collected will be used to inform a pilot and feasibility randomized controlled trial (RCT) prior to a multi site RCT to assess the program's effectiveness with the primary outcome of change in pain severity mediated by change in descending modulation.

Background Exercise is regularly utilized as a first-line treatment for knee osteoarthritis, and its use is supported by high quality evidence to improve pain and function. Reductions in perceived pain can be explained in part by exercised-induced analgesia, which is thought to be mediated via numerous endogenous pathways. Furthermore, decreased nervous system sensitivity to noxious stimuli seem to play a role in the decreased pain experience of individuals who engage in exercise. These mechanisms likely play a role in improved function and reduced pain along with the improved balance, muscle strength and flexibility that are conventionally associated with exercise. In recent years multiple guidelines for non-surgical management of knee OA have begun to include mind-body therapies, such as yoga or tai-chi, as conditional or core treatment recommendations. Structured yoga programs have been shown to result in decreased pain and improved function when compared to no exercise and conventional exercise. BDNF is a neurotrophin that appears to play an important role in the central modulation of pain in adults, and altered expression of BDNF is likely to play an important role in the pathophysiology of chronic pain. Individuals with knee OA have been shown to possess altered levels of serum BDNF compared to healthy controls, indicating that BDNF may be implicated in the pain-experience of patients with knee OA. Thus, BDNF has been identified as a therapeutic target in the treatment of pain resulting from central sensitization. NGF is a neurotrophin known to play a critical role in the proper development of the nervous system. Evidence indicates that NGF is also involved in the increased pain experience of many individuals via peripheral sensitization of nociceptive neurons. Therefore, NGF levels have been shown to be elevated in a wide variety of chronic pain conditions including knee OA. Anti-NGF therapies are being highly studied as they have significant potential to decrease pain and improve function in individuals with OA that do not respond to conventional analgesics. Objectives The aim of this study is to establish the feasibility of a pain informed movement program, in addition to education for improving pain modulation. The data collected will be used to inform a pilot and feasibility randomized controlled trial (RCT) prior to a multi site RCT to assess the program's effectiveness with the primary outcome of descending modulation as a mediator of change in pain severity. Research questions 1. Is the pain informed movement and education program feasible in terms of recruitment rate, treatment adherence, timelines, data collection procedures, patient follow-up and resources required? 2. Is the pain informed movement and education program feasible in terms of patient's satisfaction and acceptability? Study Population A convenience sample of 15 adults will be sought and is adequate to evaluate the feasibility of the program. Recruitment Participants will be recruited through the email lists of the McMaster Physical Activity Centre of Excellence (PACE) community. Recruitment posters will also be included in the McMaster Institute for Research on Aging (MIRA) newsletter. In addition, we will place postings on both PACE and MIRA social media pages. Setting The in-person 8-week exercise program will be held twice weekly at McMaster University's Physical Activity Centre of Excellence (PACE) located in the Ivor-Wynne Centre. Participants will complete the pain assessment, and have blood drawn at PACE by PACE staff who are certified phlebotomists. Assessment As part of participation in the study, participants will be asked to attend an assessment at the beginning of the study, and once again upon completing the 8-week exercise program. Participants will undergo pain modulation (CPM) testing, and the 30 Second Sit to Stand Test to determine leg strength and endurance. Lastly, participants will have their blood drawn at the beginning and end of the study. Participants will then be asked to complete a series of questionnaires about their pain and mood. Exit Survey and Focus Group A satisfaction survey will be conducted at the end of the program to evaluate the a priori feasibility criteria. Participants who indicated upon initially consenting to the study that they would like to participate in a focus group, will be contacted. Qualitative data collection will be used to explore participants experience and perceptions of the feasibility and acceptability of the program. A focus group will be conducted using audio or video recording (using Zoom), lasting between 45-60 minutes. Statistical Analysis Plan (SAP) All quantitative analyses will be conducted using SPSS 26. Descriptive statistics will be used to report feasibility outcomes, and survey responses will be summarized (using descriptive statistics) to identify trends in patient-reported outcomes. Qualitative interviews will be analyzed using Thematic content analysis to identify suggestions for program modification. Line-by-line reading of the transcripts will be performed by the authors and thematic patterns will be explored. Once themes and patterns are identified, each meaningful segment of text will be assigned a conceptual code. When conceptual codes become saturated, authors will build pattern codes where specific dimensions of clinicians' experiences will be clustered into recurring themes. Once the codes and themes are developed, participant and clinician partners will be invited to contribute to blinded data analysis to broaden interpretations and provide feedback on the quotes and emergent themes.