Pain Informed Movement for People With Knee Osteoarthritis

It is critical to understand the underlying mechanism of knee osteoarthritis (OA) pain in order to effectively manage knee OA. It has become clear that alterations in central and peripheral nervous system functioning occurs in people with knee OA and pain sensitization is a common feature. Descending modulation from the central nervous system can facilitate or inhibit nociception. Endogenous pain modulation through the descending system is an important factor as its dysregulation has significant ramifications in pain facilitation and promotion of chronic pain development and maintenance at all levels of the nervous system. The current guidelines lack focus on how to effectively manage it, which is a potential reason for why the current methods in conservative management of knee OA pain are only moderately effective. Mind-body approaches are uniquely positioned to potentially reverse the sensitization, induce positive neuroplastic changes, and improve descending pain modulation resulting in decreased pain intensity in many chronic pain populations. This study involves an exercise program which the investigators call 'Pain Informed Movement' that includes evidence-based exercises combined with mind-body techniques and pain neuroscience education. The data from this phase will be used to inform a multi-site randomized controlled trial (RCT) to assess the program's effectiveness with the primary outcome of change in pain severity mediated by change in descending pain modulation.

Exercise is regularly used as a first-line management option for knee OA, and its use is supported by high quality evidence to improve pain and function. Clinical practice guidelines for people with knee OA recommend the use of aerobic and strength training for the reduction of pain and improved physical function. Currently, one of the key components of conservative management of knee OA often implemented by clinicians is a type of exercise called neuromuscular exercise, which aims at improving sensorimotor control and the functionality of the knee joint by addressing movement in all three movement planes. Previous research has showed that the neuromuscular exercise programs designed specifically for knee OA can reduce pain, improve function, alter knee biomechanics, and improve the muscle-activation patterns of the surrounding knee musculature. While exercise is the first line treatment for knee OA and can lead to improvements in physical function and pain, it is important to highlight that it has a moderate effect, which may be short term.

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. Mind-body therapies can lead to pain reductions and improvement of function through various techniques. For instance, breathing exercises including breath awareness and regulation can activate the parasympathetic nervous system and decrease the danger signals of pain, leading to improvement of pain levels. Meditative breathing can lead to reductions in pain levels by modulating the somatosensory cortex. Relaxation techniques focused on relaxing the muscles that become tense as a result of pain and by association can re-enforce or aggravate pain, can influence the pain experience by reversing that association. Mindfulness meditation and mindful movement which can lead to a switch from sensory pain to the interoceptive awareness of the movements of the different body parts, resulting in reduced muscle tension, improvements in postural stability and proprioception, and reductions in pain levels. Mind-body therapies also lead to improvement of psychological factors such as depression, anxiety, pain catastrophizing, increasing pain acceptance, changing patients' relationships to their pain, which in turn lead to reductions in pain levels. The positive effects of mindfulness practices have been reported to last in longer-term follow ups such as 15 months, and 3 years.

Education is another core component recommended by clinical guidelines and known to be effective particularly when combined with exercise. Pain Neuroscience education (PNE) is an alternative technique of teaching patients about pain and how to rethink and re-evaluate the way pain is viewed. The use of PNE in physical therapy interventions has been steadily increasing due to its positive effects on pain and function in many chronic pain patient populations. PNE includes an explanation of the neurophysiology of pain and its process by the nervous system. This includes how pain can be modulated through upregulation or downregulation of signals to increase or decrease the pain experience and that these changes are not necessarily related to tissue damage, particularly when pain becomes chronic. PNE also provides information regarding the influence of various psychosocial aspects. By offering avenues to reconceptualize pain as a threat to the body and movement as imminent danger, patients may become more willing to participate in physical activity and tolerate slight increases in pain and discomfort.

In contrast standard OA education is the traditional and most widely used educational model in people with knee OA, focuses heavily on a pathoanatomical perspective of pain referring mainly to anatomy, biomechanics, and patho-anatomy of OA and the knee joint.

Given the importance of finding effective management strategies for pain modulation in people with knee OA, there is a need to further our understanding of the impact of evidence-based exercise combined with mind-body techniques (e.g., breathing exercises and mindfulness) with PNE on pain mechanisms.

The study is a pilot RCT with a nested qualitative component. The study will be guided by the Conceptual Framework for Defining Feasibility and Pilot studies and the Standard Protocol Items: Recommendations for Intervention Trials.

Study Population

A sample of 66 adults will be sought. The sample size is based on the primary outcome of complete follow-up using the confidence interval method for calculating sample size in pilot trials. 90% follow-up rate is the aim but the trial will be considered successful if 81% is achieved. To achieve a margin of error of 9%, with 10% added for attrition, 66 participants is required.

Recruitment Participants will be recruited through the email lists of the McMaster Physical Activity Centre of Excellence (PACE) community and the McMaster Institute for Research on Aging (MIRA) newsletter. Postings will be placed on both PACE and MIRA social media pages. In addition, the study poster will be placed on other social media channels (i.e., Twitter, Facebook advertisements). In addition, flyers will be placed in local orthopaedic surgeon, Rheumatologist and Physiatrists offices. Physicians will provide potential participants with a one-page study information sheet in lay language. If interested, potential participants can then contact the research team through the contact information provided in the flyer.

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 or in one of two local community churches. 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 conditioned undergo pain modulation (CPM) and mechanical temporal summation testing, and the 30 Second Sit to Stand Test to determine leg strength and endurance. Lastly, participants will have their blood drawn (fasting) at the beginning and end of the study. Participants will then be asked to complete a series of questionnaires about their pain and mood.

Interventions Twice weekly group exercise sessions will be 75 minutes for the intervention group and 60 minutes in duration for the control group. The intervention arm class is slightly longer due to the detailed delivery of instructions for the techniques during the class. Participants will be given instructions to complete these exercises at home at least one other time during the week for the same duration. Participants will receive education videos that are ~15-20 minutes each week, for up to 4 weeks.

Pain Informed Movement and PNE - During the neuromuscular exercise sessions, the PNE components and concepts such as mindfulness, muscle tension regulation, and breathing techniques will be applied by the instructor.

Neuromuscular exercise and standard OA education - The exercise component (i.e., the specific movements) of this group will be similar to those of the intervention group without the added mind-body techniques.

Randomization and allocation concealment Participants will be randomized with an allocation ratio of 1:1 into one of two treatment groups (Pain informed movement and PNE versus neuromuscular exercise and standard OA education) using a REDCap randomization module. Following consent and completion of baseline assessment, the assessor (different person than the recruiter) will log in to the website, open the participants' identification record and click on the randomize button. Randomization will be blocked and this process will ensure allocation concealment. As allocation concealment occurs following the baseline assessment, the assessors will be blinded at baseline and follow up assessment. Blinding of instructors is generally not possible in studies of physical interventions (i.e., exercise). Participants will be blinded to study hypotheses and the two treatment groups. As both arms of the study are providing exercise based interventions and education, participants will be provided limited details of each intervention arm so as to blind them from knowing which is the intervention and which is the control. This will help minimize any bias that occurs by knowledge of group assignment and perception of treatment effects.

Exit Survey and Focus Group In addition to the primary and secondary outcomes, 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 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.