Electrical brain stimulation may help people recover quicker from ACL injuries by maintaining leg muscle strength, new research suggests.
Edith Cowan University post-doctoral research fellow Dr Myles Murphy said that following ACL reconstructive surgery one of the biggest issues that patients had was leg muscle weakness.
“The biggest driver of this is the brain, which actually stops the contraction of important leg muscles and results in rehabilitation being less effective,” Dr Murphy said.
“The brain puts in a tremendous amount of effort to stop the contraction of these muscles.
“We know that in people with an ACL injury, over a period of time, the brain actually starts to recruit unrelated parts of the brain, like the visual centres, to help activate leg muscles.”
Dr Murphy said that even with exercise rehabilitation, people with ACL reconstruction struggled to regain quadriceps strength and voluntary activation.
However, according to new research conducted by Dr Murphy and West Coast Eagles head physician Dr Casey Whife, electrical brain stimulation could change that.
The pair has shown that by putting a small electrical current through the part of the brain responsible for leg muscles then the muscle strength could be maintained while patients were undertaking standard rehabilitation exercises, and the work of other parts of the brain was eased.
Dr Murphy said electrical brain stimulation had been around for decades and was used in other areas such as treating mental health disorders or neurological conditions.
“Because the current is so small, and is delivered externally, patients only report feeling ‘tingling or itchiness’ at the point where the sponges are connected to the head,” he said.
The research, thought to be a world-first, has shown that electrical brain stimulation appeared effective at improving primary motor cortex disfunction following ACL reconstruction.
Dr Whife said long-term concerns had led him and Dr Murphy to devise new rehabilitative techniques.
“We know that persisting quadriceps weakness leads to poor long-term outcomes, such as reduced participation in sports and increased rates of osteoarthritis,” he said.
“So we wondered, how can we mitigate these brain changes driving persisting muscle weakness?
“This study highlights a significant step forward in addressing the neural barriers to recovery after ACL reconstruction.
“By targeting cortical inhibition, we are paving the way for more effective and efficient rehabilitation strategies, which could help patients regain strength and function sooner.”
Dr Murphy said he was still reviewing the long-term impact of an electrical intervention on injury recovery and outcomes.
“Electrical brain stimulation during rehabilitation could represent a low-cost, simple to apply intervention, which could be performed as an adjunct to current exercise rehabilitation that may address maladaptive changes to the primary motor cortex postoperatively,” he said.
Dr Murphy recommended patients be screened to make sure that commercially available electrical devices were safe for individual use.
Patients with cochlear implants, pacemakers or other implanted devices, for example, would be unable to use this type of intervention.