New study reveals why exercise doesn’t work out for some osteoarthritis patients

Exercise is one of the key recommendations for patients with osteoarthritis. Strong muscles protect weakened joints, reduce pressure on them, and help slow the progression of this degenerative condition.

Unfortunately, osteoarthritis pain makes many patients less active. Now, Australian scientists have discovered another problem. people
People with osteoarthritis cannot activate their muscles as efficiently as people without joint problems.

“If you try to build muscle, you don’t get stronger as quickly,” says Miles Murphy, a sports and exercise physiotherapist and researcher at Edith Cowan University.

He was interested in understanding why people suffering from arthritis do not achieve the muscle strength gains and pain relief that exercise rehabilitation aims to achieve. “We wanted to investigate whether there was something going on in their brains that might be causing some impairment in their recovery.”

Murphy and his team tested 41 people, 17 of whom had hip osteoarthritis, to study brain function and how it affects muscle strength. All participants were 59 years old, as osteoarthritis tends to develop in middle age.

Regardless of muscle strength, the hip arthritis group was unable to properly activate their muscles. “The brain actively puts on the brakes to prevent muscle use,” Murphy explains. “This seems to be a short-term defensive response that went awry.”

In the early stages of an injury, this can be helpful and prevents you from overdoing it and causing further damage. Chronic conditions such as osteoarthritis can hinder recovery.

All participants in Edith Cowan’s study were asked to perform exercises that measured leg strength while exerting their maximum capacity.

“We asked them to push 100 percent. We were yelling at them to work hard,” Murphy says. “Even though patients with hip arthritis think they are 100% contracting, in reality only about 90% of their muscle fibers are activated, whereas the group without problems activated about 95% of their muscle fibers. It wasn’t for lack of effort. They were doing the best they could.”

What the researchers did next was to send electrical signals to the nerves in the hip joint that activated the leg muscles, overriding the brain and providing a boost. This reveals the difference between what a person’s body wants and what it can actually do. “It’s not a very good test, but it does give us some good data,” Murphy said.

There is no cure for osteoarthritis, but exercise rehabilitation under the guidance of a physical therapist or exercise physiologist can help reduce pain and improve physical performance. There are also some useful online tools. Arthritis New Zealand has a YouTube channel with exercises to help manage arthritis. A combination of aerobic exercise, strength training, stretching, and balance exercises is ideal.

People with osteoarthritis must make special efforts to strengthen their muscles and maintain their strength. However, there are some tricks that can interfere with your brain’s overprotective response.

“One is to exercise to the beat of a metronome,” says Murphy. “If you’re at the gym, put it on in your headphones and do a slow, focused workout to the beat. This will help you override your brain a little bit.”

Another technique he suggests is blood flow restriction training. BFR involves wearing a pressure band, much like a blood pressure cuff, during training. This traps lactic acid in your muscle tissue, tricking your brain into thinking you’re working harder than you are, allowing you to build muscle and improve strength without worsening joint pain. There is some science that shows it can help people with knee osteoarthritis.

Murphy, on the other hand, is working on a more novel approach. “We’re looking at ways to improve symptoms in patients with hip osteoarthritis by passing a small electrical current through the brain, so they’re undergoing standard physical therapy rehabilitation, but… We’re wearing fancy headsets that give us a little bit of outside help to take the brakes off and overcome the problems we’re seeing.”