A Biomechanical Exercise Program for Knee OA

Prescribing exercise for people with painful knee osteoarthritis (OA) is essential for pain management, improved function, and chronic disease prevention. Exercise that decreases joint exposure to damaging loading while eliciting adequate muscular activation for strength improvements is ideal. The purpose of this 3-arm RCT is to compare mobility, strength, pain, and MRI outcomes between the low-loading biomechanical exercise program (BE), a traditional exercise program for knee OA (TE), and a control group completing meditation classes (M).

Osteoarthritis (OA) is a common joint disease affecting 1 in 10 Canadians. Osteoarthritis commonly presents in the knee joint and is associated with mobility limitations, pain, and an increased risk of other chronic health conditions such as heart disease. It is critical to implement exercise for people with knee OA as it can be an effective method for improving pain, mobility, and cardiovascular health. A biomechanical exercise program using static yoga postures has been established in the investigators lab based on minimizing damaging knee joint loads, while effectively exercising the musculature around the knee joint. The investigators pilot project (REB#13-510) showed that a 12-week yoga program using these biomechanical exercises improved pain and mobility while keeping the medial joint loading well below that experienced during normal level walking. The next step with this exercise program is to compare clinical and tissue outcomes with that of a regularly prescribed aerobic and strengthening program, as well as a control group completing meditation classes. The investigators aim to identify differences in clinical mobility performance outcomes, muscle and fat volumes using magnetic resonance imaging (MRI), and cartilage integrity using MRI between the three groups using a randomized controlled trial (RCT) design.

The participants in this arm will be asked to attend 3 group classes per week for 12 weeks at a local yoga studio taught by a certified yoga instructor. Four class times will be offered per week. These classes will include a warm-up, static poses shown to decrease knee joint loading, and a cool down including flexibility exercises. Measurements will be obtained at baseline (before intervention) and at follow-up (following intervention). Outcomes will include clinical mobility; muscle and fat volumes, and cartilage morphology using MRI; pain; isometric leg strength; cardiovascular fitness; and gait analysis.

The participants in this arm will be prescribed an aerobic and strengthening exercise program often prescribed to those with knee OA. The program will include 15 minutes of walking per class, closed kinetic chain strengthening exercises on machines, and a cool down consisting of stretching. Participants will be asked to come to class 3 times per week for 12 weeks. Certified Kinesiologists as well as student volunteers will be available during all class times for program completion and progression.

The participants in this arm will be asked to attend 3 meditation classes per week for 12 weeks taught by a certified yoga instructor with a specialization in meditation. This will take place at an alternate yoga studio to avoid contamination. Since it is known that exercise is beneficial for pain management and strengthening in knee OA, participants randomized to the control group will be offered a free exercise pass following completion of the study.

A biomechanical exercise program shown to decrease joint loading will be administered 3 times a week for 12 weeks. Outcomes will include mobility performance; pain; muscle and fat volumes, and cartilage morphology using MRI; strength; cardiovascular fitness; and gait analysis.

A traditional exercise program for people with knee OA will be administered 3 times a week for 12 weeks. Outcomes will include mobility performance; pain; muscle and fat volumes, and cartilage morphology using MRI; strength; cardiovascular fitness; and gait analysis.

A meditation program acting as a control will be administered 3 times a week for 12 weeks. Outcomes will include mobility performance; pain; muscle and fat volumes, and cartilage morphology using MRI; strength; cardiovascular fitness; and gait analysis.

The Lower Extremity Function Scale (LEFS) consists of 20 items, on an adjectival scale, that assess difficulty during mobility tasks ranging from transfers to running. The LEFS is scored from 0 to 80 with higher scores represent better self-reported physical function. It is reliable and valid in knee OA and has superior sensitivity to change compared to similar measures. The mean (95% confidence interval) difference score (follow-up score - baseline score) was computed for each of the three study arms.

Change in self-reported knee pain was assessed with 3 valid and reliable questionnaires: the Knee injury and Osteoarthritis Outcome Score (KOOS), the Intermittent and Constant Osteoarthritis Pain (ICOAP) score, and the Numeric Pain Rating Scale (NPRS). The KOOS pain score represents a normalized score from 0 (extreme symptoms) to 100 (no symptoms). KOOS scores closer to 100 indicate fewer symptoms. The ICOAP consists of two sub-scales: constant pain (5 items) and intermittent pain (6 items). The score from each subscale represents a normalized score from 0 (no pain) to 100 (extreme pain). ICOAP scores closer to 0 indicate less pain. The NPRS pain score represents a score from 0 (no pain) to 10 (worst possible pain). NPRS ratings were provided following maximum isometric knee extensor exertions and flexor exertions. The mean (95% confidence interval) difference score (follow-up score - baseline score) was computed for each of the three study arms.

The Arthritis Self-Efficacy Scale (ASES) measures arthritis-specific beliefs regarding perception of performance on certain tasks to cope with the disease. The ASES is measured using 20 questions on a 10-100 scale with respect to three main areas: pain management (5 questions), physical function (9 questions), and other symptoms (6 questions). Higher numbers indicate greater certainty that a participant can cope with a particular task as a consequence of their disease. The mean (95% confidence interval) difference score (follow-up score - baseline score) was computed for each of the three study arms.

Depression was assessed with the Centre of Epidemiological Studies Depression (CES-D) Scale, a 20-item scale developed for the general population with emphasis on affect. Elements of affect include mood, guilt, worthlessness, helplessness, appetite, and sleep. The CES-D is scored from 0 to 60 with a score of 16 or higher indicating depression. The mean (95% confidence interval) difference score (follow-up score - baseline score) was computed for each of the three study arms.

Frailty was assessed using the Edmonton Frail Scale (EFS). The EFS is a brief screening interview for older adults to assess frailty that is commonly used in both inpatient and outpatient settings. The scale covers 8 domains: cognition, general health status, functional independence, social support, medication use, nutrition, mood, continence, and functional performance (defined as performance on the Timed Up and Go [TUG] test). The test is scored out of 17, with higher scores indicating higher levels of frailty. The mean (95% confidence interval) difference score (follow-up score - baseline score) was computed for each of the three study arms.

Mobility performance was measured using the Six-Minute Walk Test. For this test, participants are instructed to walk as far as possible in 6 minutes. The distance covered in 6 minutes is recorded. This measure has produced reliable and valid data in persons with knee OA. The mean (95% confidence interval) difference in distance in metres (follow-up - baseline) was computed for each of the three study arms.

Mobility performance was measured using the 40m Walk Test. This test measures the time taken to complete a fast-paced 40m walk. This measure has produced reliable and valid data in persons with knee OA. The mean (95% confidence interval) difference in time in seconds (follow-up - baseline) was computed for each of the three study arms.

Mobility performance was measured using the 30-second Chair Stand Test. This test measures the number of times participants can rise and lower from a standard height chair, without using arm rests, in a 30-second period. This measure has produced reliable and valid data in persons with knee OA. The mean (95% confidence interval) difference in number (follow-up - baseline) was computed for each of the three study arms.

Mobility performance was measured using the Timed Up and Go Test. This test measures the time taken to rise from a standard chair with arm rests, walk 3m, and return to a seated position. This measure has produced reliable and valid data in persons with knee OA. The mean (95% confidence interval) difference in time in seconds (follow-up - baseline) was computed for each of the three study arms.

Mobility performance was measured using the Stair Ascent Test. For this test, the time taken to ascent nine stairs is recorded. The mean (95% confidence interval) difference in time in seconds (follow-up - baseline) was computed for each of the three study arms.

The peak torque developed during knee extension and flexion during a maximum voluntary isometric contraction was measured by use of a Biodex System 2 isokinetic dynamometer. The mean (95% confidence interval) difference in torque (follow-up - baseline) was computed for each of the three study arms. Data is presented as Nm/kg.

The peak isokinetic torque developed during knee extension and flexion at 25% resistance of their maximum voluntary isometric contraction was measured by use of a Biodex System 2 isokinetic dynamometer. The mean (95% confidence interval) difference in power (follow-up - baseline) was computed for each of the three study arms. Data is expressed in W/kg.

Peak grip strength was assessed using a Jamar hand dynamometer. The hand dynamometer was set to a fixed position and all values of grip force were expressed in kg. The mean (95% confidence interval) difference in absolute force (follow-up - baseline) was computed for each of the three study arms.

Peak grip strength was assessed using a Jamar hand dynamometer. The hand dynamometer was set to a fixed position and all values of grip force were expressed in kg/kg (grip force/body mass). The mean (95% confidence interval) difference in relative force (follow-up - baseline) was computed for each of the three study arms.

Cardiovascular fitness will be calculated using the YMCA submaximal cycle ergometry test. Predictions of VO2max will be made from heart rate (measured with a heart rate monitor) and load (Watts).

Muscle and fat volumes from magnetic resonance images will be segmented using a custom program. The images will be acquired using a • Iterative Decomposition of water and fat with Echo Asymmetry and Least-squares estimation (IDEAL) sequence on a 3.0T MR750 Discovery research-grade scanner.

Cartilage morphology will be assessed in open-sourced and custom programs. Sodium (23Na+) images and T2 mapping will be completed on the 3.0T MR750 DIscovery research-grade scanner. The mean (95% confidence interval) percent change from baseline to follow-up was computed for each of the three study arms.

Cytokines interleukin-6 (IL6), tumour necrosis factor (TNF), and interleukin-10 (IL10) are important markers of the inflammatory response. These markers will be assessed using standard blood draw and nasal swabs collected by a medical professional. The mean (95% confidence interval) difference in concentration in pg/ml (follow-up - baseline) was computed for each of the three study arms.

C-reactive protein (CRP) is an important marker of the inflammatory response. This markers will be assessed using standard blood draw and nasal swabs collected by a medical professional. The mean (95% confidence interval) difference in concentration in ug/ml (follow-up - baseline) was computed for each of the three study arms.

Inclusion Criteria: 50 years of age or older Knee pain on most days of the week Less than 30 minutes of morning stiffness Bony enlargement Bony tenderness to palpation Signs of inflammation Able to safely climb 2 flights of stairs without aid Exclusion Criteria: Any other forms of arthritis Osteoporosis History of patellofemoral symptoms Active non-arthritic knee disease Knee surgery Use of cane or walking aid Unstable heart condition Neurological conditions Skin allergy to medical tape Hip or ankle injuries in past 3 months Any injuries that would prohibit participation in yoga Ipsilateral hip or ankle conditions Currently receiving cancer treatment Currently pregnant

Kuntz AB, Chopp-Hurley JN, Brenneman EC, Karampatos S, Wiebenga EG, Adachi JD, Noseworthy MD, Maly MR. Efficacy of a biomechanically-based yoga exercise program in knee osteoarthritis: A randomized controlled trial. PLoS One. 2018 Apr 17;13(4):e0195653. doi: 10.1371/journal.pone.0195653. eCollection 2018.