Investigating the Effect of Interval Walking and Qigong on People With Knee Osteoarthritis: Pilot Study

For comprehensive pain assessment: The Measure of Intermittent and Constant Osteoarthritis Pain (ICOAP) scale. ICOAP is a multidimensional measure developed to evaluate the pain in subjects with KOA, comprehensively. ICOAP assesses both pain intensity and frequency in addition to assessing the impact of pain on sleep, and quality of life (physical function). ICOAP has high reliability (0.85) and validity (0.60-0.81). ICOAP is 11-points scale to assess OA pain with maximum score 100.

rHR and HRR will be measured using a Polar OH1 optical HR sensor (Polar Electro Inc., New York), which is in high agreement with ECG measured HR and is validated to be used in lab sittings. HRR is defined as the range of the change of HR from the peak after the exercise to one-minute post-exercise. Slow HRR is a warning of decline of cardiovascular/autonomic function. The HR should decrease at least 12 beats after one minute after exercise termination, otherwise this is considered as an abnormal response. The HRR will be measured post the 6-minute walk test, which has been approved to be as effective in testing HRR as vigorous exercises. The HR will be measured before the exercise (rHR), immediately after the exercise (the peak HR), and one minute after the exercise(1-min-post). Then, the difference between the peak HR and the 1-min-post will be calculated.

HRV will be estimated using an ECG system via analyzing the HRV frequency and time domain. Standard lead II configuration will be used by placing three disposable electrodes over the participant's chest to record the ECG signals. We will collect the ECG signal at 2000 Hz sampling rate.The subject will be asked to sit relaxed in a quiet room with a temperature between 22 and 24°C, for 10 minutes. Then, the HRV ECG recording will be collected over a 5-minute period while participants are asked to not move or speak over the next 5 minutes when HRV will be collected. BIOPAC AcqKnowledge 5.0 software will be utilized to collect both the frequency and the time parameters of HRV. The frequency parameters are LF power (0.04-0.15 Hz) and HF power (0.15-0.4 Hz) and LF/HF ratio, while the time parameters includes RMSSD.

SBP will be measures using an automatic device, Microlife BP monitor.

Insomnia Severity Index is a 7-item questionnaire that is a global measure of perceived insomnia severity, with its reliability and validity have been reported.

Sleeping Quality Assessment will use Pittsburgh Sleep Quality Index (PSQI) with high test-retest reliability and construct validity.

Fatigue will be measured using Multidimensional Fatigue Inventory (MFI-20), with proved internal consistency, validity, and utilized in research of OA.

The 15-item questionnaire of the Geriatric Depression Scale will be used, which is a valid measurement of depression.

Injury and Osteoarthritis Outcome Score (KOOS) is a valid and reliable instrument and will be used for short-term and long-term follow-up of knee OA. KOOS consists of 42 items. A Likert scale is used for each sub-scale and items have five possible answer options scored from 0 (No Problems) to 4 (Extreme Problems) and each of the five scores is calculated as the sum of the items included. Scores are transformed to a 0-100 scale. Zero representing extreme knee problems and 100 representing no knee problems.

in 5 separately scored subscales; Pain, other Symptoms, Function in daily living (ADL), Function in Sport and Recreation (Sport/Rec), and knee-related Quality of Life (QOL).

The SF-36 measures eight scales: physical functioning, role physical, bodily pain, general health, vitality, social functioning, role emotional, and mental health. Each scale is directly transformed into a 0-100 scale on the assumption that each question carries equal weight. The lower the score the more disability.

The inflammatory biomarker assessments will use venous blood samples drawn from subjects. Approximately 10 ml of blood will be collected from fasting subjects, between 8 am to 10 am. The serum will be assayed for the levels of inflammatory markers: TNF-α, IL-1β, IL-6, IL-8, IL-17, and C-reactive protein, using respective ELISA kits available from Thermo Scientific, Inc (Rockford, IL).

The 6-minute walk test will be used to assess the fitness level at the baseline and after completing the intervention. We will follow the guideline of the American Thoracic Society to conduct this test as the improvement in walking distance indicates the improvement of aerobic fitness.

Pain intensity level will be assessed using 100 mm horizontal VAS, which is a valid and reliable pain scale. The VAS is reported to be a sensitive measurement to hourly and weekly assessment of pain level, and a reduction of 10mm is reported to be the minimum clinical important difference for people with chronic pain such as in OA. The subjects in both groups will be asked to score their pain before and after each session of the walking exercise, and the averaged range of change from pre to post walking will be used in data analysis.

In addition, for change of pain from baseline to post intervention, the participant will be asked to report their minimum and maximum pain during the last 24 hours, and their current pain on the VAS ruler. Then, the average of the measure taken 3 different times will be used in the analysis.