Effect of High-Intensity Strength Training on Knee Pain and Knee Joint Compressive Forces Among Adults With Knee Osteoarthritis: The START Randomized Clinical Trial

• Published in: JAMA : the journal of the American Medical Association 2021-02, Vol.325 (7), p.646-657
• Main Authors: Messier, Stephen P, Mihalko, Shannon L, Beavers, Daniel P, Nicklas, Barbara J, DeVita, Paul, Carr, J. Jeffery, Hunter, David J, Lyles, Mary, Guermazi, Ali, Bennell, Kim L, Loeser, Richard F
• Format: Article
• Language: English
• Subjects: Adults; Adverse events; Aged; Arthritis; Biomedical materials; Body mass; Body Mass Index; Body size; Clinical trials; Compressive Strength; Contact force; Female; Follow-Up Studies; Humans; Joints (anatomy); Knee; Knee Joint - physiology; Male; Middle Aged; Muscles; Original Investigation; Osteoarthritis; Osteoarthritis, Knee - complications; Osteoarthritis, Knee - physiopathology; Osteoarthritis, Knee - therapy; Pain; Pain - etiology; Pain - rehabilitation; Pain Management - methods; Pain Measurement; Physical training; Research facilities; Resistance Training - methods; Signs and symptoms; Single-Blind Method; Sports training; Strength training; Thigh; Tibia; Training; Walking
• ISSN: 0098-7484; 1538-3598
• DOI: 10.1001/jama.2021.0411

IMPORTANCE: Thigh muscle weakness is associated with knee discomfort and osteoarthritis disease progression. Little is known about the efficacy of high-intensity strength training in patients with knee osteoarthritis or whether it may worsen knee symptoms. OBJECTIVE: To determine whether high-intensity strength training reduces knee pain and knee joint compressive forces more than low-intensity strength training and more than attention control in patients with knee osteoarthritis. DESIGN, SETTING, AND PARTICIPANTS: Assessor-blinded randomized clinical trial conducted at a university research center in North Carolina that included 377 community-dwelling adults (≥50 years) with body mass index (BMI) ranging from 20 to 45 and with knee pain and radiographic knee osteoarthritis. Enrollment occurred between July 2012 and February 2016, and follow-up was completed September 2017. INTERVENTIONS: Participants were randomized to high-intensity strength training (n = 127), low-intensity strength training (n = 126), or attention control (n = 124). MAIN OUTCOMES AND MEASURES: Primary outcomes at the 18-month follow-up were Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) knee pain (0 best-20 worst; minimally clinically important difference [MCID, 2]) and knee joint compressive force, defined as the maximal tibiofemoral contact force exerted along the long axis of the tibia during walking (MCID, unknown). RESULTS: Among 377 randomized participants (mean age, 65 years; 151 women [40%]), 320 (85%) completed the trial. Mean adjusted (sex, baseline BMI, baseline outcome values) WOMAC pain scores at the 18-month follow-up were not statistically significantly different between the high-intensity group and the control group (5.1 vs 4.9; adjusted difference, 0.2; 95% CI, −0.6 to 1.1; P = .61) or between the high-intensity and low-intensity groups (5.1 vs 4.4; adjusted difference, 0.7; 95% CI, −0.1 to 1.6; P = .08). Mean knee joint compressive forces were not statistically significantly different between the high-intensity group and the control group (2453 N vs 2512 N; adjusted difference, −58; 95% CI, −282 to 165 N; P = .61), or between the high-intensity and low-intensity groups (2453 N vs 2475 N; adjusted difference, −21; 95% CI, −235 to 193 N; P = .85). There were 87 nonserious adverse events (high-intensity, 53; low-intensity, 30; control, 4) and 13 serious adverse events unrelated to the study (high-intensity, 5; low-intensity, 3; control, 5). CONCLUSION