Progressive resistance training (PRT) and neuromuscular exercise (NEMEX) programs result in similar improvements in hip function, pain, and hip-related quality of life (QOL) in people with osteoarthritis (OA), according to the results of a randomized controlled trial.
At the end of the 12-week exercise period, both interventions yielded changes from baseline on the 30-second chair stand test (30s-CST) that were below the threshold for a major clinical effect.
Mean changes in the Hip Disability and Osteoarthritis Outcome Score (HOOS) pain subscale and HOOS QOL score were also similar among the participants, regardless of which exercise program they had been assigned to.
“The lack of superiority of PRT for increasing muscle strength and power is surprising given the principle of specificity (higher-intensity resistance training yields greater improvements in maximal muscle strength),” according to the Danish researchers who reported the results online today in Annals of Internal Medicine.
“However, the point estimates only showed modest and uncertain superiority of PRT for increasing muscle strength and power and no differences for any functional performance tests or self-reported physical function,” they added.
The Power of Exercise
Worldwide, most clinical guidelines recommend exercise as a first-line conservative treatment option in both hip and knee OA. However, there is not much evidence to help guide healthcare practitioners in deciding which type of exercises to use with their patients, Troels Kjeldsen, MSc, the principal investigator for the study, told this news organization.
“Neuromuscular exercise is a very commonly used exercise program in clinical practice, but, to our knowledge, it has never been compared to another type of exercise in hip OA,” observed Mr. Kjeldsen, who is a PhD student in the department of orthopedic surgery at Aarhus University Hospital, Aarhus, Denmark.
“Each year, many thousands of patients are referred to having neuromuscular exercise therapy with a physiotherapist,” Mr. Kjeldsen said. “So, we thought it would be worthwhile to compare it to PRT, another promising exercise type, to see if it really did perform as well as I think most people thought it did,” he added.
Comparing the Two Exercise Programs
PRT and NEMEX are two different types of exercise programs. PRT involves using resistance-training machines, and the focus is to maximize the exercise intensity by using as high an exercise load or weight as possible. By contrast, NEMEX consists of exercises that are low to moderate in intensity and emphasizes alignment, control, and stability of the movements.
To compare the two exercise strategies, Mr. Kjeldsen and fellow investigators recruited 160 participants at five hospitals and 10 physiotherapy clinics across three of five healthcare regions in Denmark.
For inclusion in the trial, the participants had to have a clinical diagnosis of hip OA, be older than 45 years, and experience pain during activity in one or both hips that was rated as 3 or higher on a 10-point numerical rating scale. Participants also had to have no or less than 30 minutes of hip joint stiffness in the morning as well as no surgery involving the lower extremities in the previous 6 months.
Participants were then randomized to undertake the PRT (n = 82) or NEMEX (n = 78) program, delivered as two physiotherapist-led group sessions every week for 12 weeks. Exercise sessions were held at least 72 hours apart and consisted of a 10-minute warm-up on an exercise bike and then 50 minutes of PRT or NEMEX. PRT consisted of five generic resistance-based exercises targeting hip and knee joint muscles and NEMEX consisted of 10 exercises that increased in difficulty by varying the number, direction, speed, and surface of the movements performed.