Upper and Lower Extremity Exercise and Exercise-Induced Hypoalgesia in Knee Osteoarthritis

Study Overview
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Brief Summary
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The objective of the study is to explore the effects of arm exercise (UE, arm ergometer) vs. leg exercise (LE, cycling ergometer) on exercise-induced hypoalgesia (EIH), central pain mechanisms and knee pain in people with knee osteoarthritis (OA). Furthermore, we will explore relations of socioeconomic status, racial discrimination, acculturative stress, and autonomic function to exercise effects on EIH, central pain mechanisms, and knee pain. This will be a pilot randomized cross-over study where all participants undergo Day 1 (baseline assessments), Day 2 (UE or LE), and Day 3 (UE or LE).

Official Title
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Comparing Effects of Upper Extremity Versus Lower Extremity Exercise on Exercise-Induced Hypoalgesia in People With Knee Osteoarthritis: A Pilot Cross-over Study

Conditions
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Knee Osteoarthritis, Knee Pain Chronic, Central Pain Syndrome

Intervention / Treatment
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* Other: Exercise


Participation Criteria
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Eligibility Criteria
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Participants with knee OA (Target n=40) Inclusion Criteria: We will recruit participants with knee OA, using the National Institute for Health and Care Excellence's clinical diagnostic criteria, which does not require radiographs. The clinical diagnostic criteria include: age ≥45 activity-related knee pain either no morning joint-related stiffness or stiffness that lasts ≤ 30 minutes. knee pain at least 4 on a 0-10 pain scale knee pain as a chief complaint if having multiple pain understand English Exclusion Criteria: peripheral neuropathy or other sensation loss on the body sites for pain measurements (i.e., the wrist, knee, the forearm) use of medical devices electrically active (e.g., pacemaker) chronic use of opioids pregnant women serious and uncontrolled concomitant disease, including cardiovascular, nervous system, pulmonary, renal, hepatic, metabolic, hormonal, endocrine, gastrointestinal or epileptic disease rheumatoid arthritis, ankylosing spondylitis, and any neurological disorders that prevent the study procedure cognitive impairment history of a knee replacement surgery inability to perform exercise due to severe pain or other symptoms any intervention procedures for knee pain in the last 3 months Inclusion and exclusion criteria for pain-free controls (Target n = 20) Pain-free controls are not having a pain-related medical condition. They have to speak and understand English. Pain-free controls are excluded if they had experienced a pain episode, caused by musculoskeletal injury or otherwise in the previous 3 months.

Ages Eligible for Study
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Minimum Age: 45 Years
Maximum Age: 90 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: This will be a pilot randomized cross-over study. Once enrolled, all participants will undergo 3 laboratory visits, each separated at least by a week as a wash-out period: day 1, baseline assessment; day 2, randomized to either arm exercise (AE) or leg exercise (LE) ; and day 3, AE or LE alternative to the exercise on day 2.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Exercise<br>Arm 1: All participants, knee OA and pain-free individuals, will undergo a single exercise of arm exercise using an arm ergometer and; | Other: Exercise<br>* Arm exercise will be an arm ergometer for 20 minutes, preceded by a 5-minute warm-up. Leg exercise will be a cycling ergometer for 20 minutes, preceded by a 5-minute warm-up. The exercise intensity will be set at 70% of the heart rate reserve (HRR) for each type of exercise.<br>* Other names: Leg exercise;|
| Active Comparator: Lower Body Exercise<br>Arm 2: All participants, knee OA and pain-free individuals, will undergo a single exercise of leg exercise using a cycling ergometer. | Other: Exercise<br>* Arm exercise will be an arm ergometer for 20 minutes, preceded by a 5-minute warm-up. Leg exercise will be a cycling ergometer for 20 minutes, preceded by a 5-minute warm-up. The exercise intensity will be set at 70% of the heart rate reserve (HRR) for each type of exercise.<br>* Other names: Leg exercise;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in pressure pain thresholds (Measure of exercise-induced hypoalgesia) | Pressure pain thresholds (PPT) will be assessed at the wrist and patella. PPT being assessed at a remote body site (e.g., wrist) is to measure central pain sensitivity while PPT being assessed at the location of pain (i.e., knee, patellae) is to assess peripheral pain sensitivity with or without central pain sensitivity. PPT will be assessed using a handheld pressure algometer with 1 cm2 rubber tip. PPT will be defined as the point at which the participant verbally indicated that the pressure first changed to slight pain. A lower PPT value (Kgf) represents greater pain sensitivity. PPT will be assessed 3 times at each location and averaged. Furthermore, changes in PPT after exercise has been used to assess the degree of exercise-induced hypoalgesia (EIH). When PPT values increase after the exercise, it indicates a reduction of pain sensitivity and, therefore, an effect of EIH. | Day 1: PPT will be assessed twice. PPT assessment --> 25 minutes of waiting --> PPT assessment; Time frame of Days 2 and 3 will be the same except 25 minutes of waiting time. It will be 25 minutes of exercise (either AE or LE) on Days 2 and 3 | 
| Mechanical temporal summation | Temporal summation (TS) is a sensitive measurement of central pain sensitivity. Investigators will assess TS using a standard set of weighted probes from 64-512 mN. Participants will rate the pain experienced by each successive weighted probe being touched on the skin of the wrist until a pain rating of ≥ 4/10 is achieved. The selected probe will be then applied at a frequency of 1 Hz for 10 seconds on the wrist. Participants will provide a pain rating at the completion of the train of 10 stimulations and 15 seconds post-stimulation. TS will be defined as the difference between the highest post-stimulation pain rating and the initial pain rating. A post-stimulation pain rating greater than the initial pain rating will be considered to be reflective of an increase in central pain sensitivity. | Day 1: TS will be assessed twice. TS assessment --> 25 minutes of waiting --> TS assessment; Time frame of Days 2 and 3 will be the same except 25 minutes of waiting time. It will be 25 minutes of exercise (either AE or LE) on Days 2 and 3 | 
| Conditioned pain modulation | Conditioned pain modulation (CPM) evaluates the adequacy of the descending pain modulatory pathways, which contributes to central pain sensitivity. Investigators will assess CPM using PPT as the test stimulus (PPT1) at the wrist as described above, with forearm ischemia using a blood pressure cuff as the conditioning stimulus. Briefly, the blood pressure cuff applied to the contralateral arm will be inflated to 10mm Hg above systolic pressure. The participant will be then instructed to perform hand grip squeezes until pain of at least 4/10 occurs in the contralateral arm. PPT will be then reassessed at the wrist 3 times and averaged (PPT2). Percent efficiency of CPM (%CPM) was computed as PPT2/PPT1, multiplied by 100; %CPM ≤ 100 indicates inefficient CPM. | Day 1: CPM will be assessed twice. CPM assessment --> 25 minutes of waiting --> CPM assessment; Time frame of Days 2 and 3 will be the same except 25 minutes of waiting time. It will be 25 minutes of exercise (either AE or LE) on Days 2 and 3 | 
| Knee pain | We will assess changes in knee pain with a 20 meter walk using a 0-10 numeric rating scale where 0 indicates no knee pain and 10 indicates the worst knee pain. | Day 1: knee pain will be assessed twice. Knee pain assessment --> 25 minutes of waiting --> knee pain assessment; Time frame of Days 2 and 3 will be the same except 25 minutes of waiting time. It will be 25 minutes of exercise (either AE or LE) on Days 2 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Racial discrimination | Racial discrimination will be assessed with the Perceived Experiences of Discrimination Questionnaire-Community Version (PEDQ-CV). This is a reliable and valid 17-item survey that assesses experiences of racialized discrimination. | Day 1 after obtaining the informed consent form | 
| Acculturative Stress | Acculturative stress will be assessed with The Social, Attitudinal, Familial, Environment Acculturative Stress Scale (SAFE). SAFE is composed of 24 items that measure stress as a result of the acculturation process in four contexts: social, attitudinal, familial and environmental acculturative. | Day 1 after obtaining the informed consent form | 
| Autonomic function | Heart rate variability (HRV), a measurement of autonomic function, will be assessed using a wearable and wireless heart rate monitor. Investigators will have participants lie supine for 5 minutes to collect heart rate variability parameters such as high frequency and high-frequency/low-frequency ratio. | Day 1 after obtaining the informed consent form | 
| The Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) | WOMAC knee pain scale ranges 0-20 with 5 questions assessing knee pain in different contexts such as knee pain during walking and pain during standing. Each question has a score of 0-4. A greater WOMAC score represents greater knee pain. | Day 1 after obtaining the informed consent form | 
| Pain catastrophizing scale (PCS) | The Pain Catastrophizing Scale is a validated 13-item scale with questions related to catastrophizing behavior. The total score is 52 with higher scores indicating greater catastrophic thoughts. | Day 1 after obtaining the informed consent form | 
| Pittsburgh sleep quality index (PSQI) | The Pittsburgh Sleep Quality Index (PSQI) is a self-reported questionnaire. PSQI contains 19 individual items, creating seven components that produce one global score, ranging from 0 to 21. A score of 0-4 indicates the absence of sleep problems, while scores 5 and higher indicate poor sleep quality. | Day 1 after obtaining the informed consent form | 
| Hospital anxiety and depression scale (HADS) | HADS contains seven questions about anxiety and seven questions about depression, with a 0-3 score for each question. Higher scores indicate greater anxiety and depression. | Day 1 after obtaining the informed consent form | 
| Physical activity | Physical activity will be assessed with International Physical Activity Questionnaire (IPAQ). IPAQ is a 27-item self-reported measure of physical activity. Results can be reported in categorical (low activity levels, moderate activity levels or high activity levels) or as a continuous variable (MET minutes a week). MET minutes represent the amount of energy expended carrying out physical activity. | Day 1 after obtaining the informed consent form | 
| Instrument support | Instrument support will be assessed with the PROMIS SFv2.0 Instrumental Support 6a questionnaire. This is a 6-item questionnaire with a 5-point Likert scale ranging from never to Always. Each score will be standardized to T-scores with mean of 50 standard deviation of 10. A higher score indicates having more support. | Day 1 after obtaining the informed consent form | 
| Emotional support | Emotional support will be assessed with the PROMIS SFv2.0 Emotional Support 6a questionnaire. This is a 6-item questionnaire with a 5-point Likert scale ranging from never to Always. Each score will be standardized to T-scores with mean of 50 standard deviation of 10. A higher score indicates having more support. | Day 1 after obtaining the informed consent form | 
| Positive and negative affect | The Positive and Negative Affect Schedule (PANAS) is a 20-item measure that consists of 10 positive items (e.g., excited, proud) and 10 negative items (e.g., distressed, scared). Items are self-rated on a 5-point Likert-type scale ranging from 1 (very slightly or not at all) to 5 (extremely) and summed to produce total subscale scores for positive and negative affect ranging from 10 to 50, with higher scores representing higher levels of each subscale | Day 1 after obtaining the informed consent form |