By John Salak –
New research out of Australia may have astounding and positive impacts in the battle to improve strength and reverse muscle loss in immobilized limbs.
Edith Cowan University (ECU) reports that training one arm can improve strength and decrease muscle loss in the other arm—without even moving it.
The study focused on the use of eccentric exercises, which involves lengthening a contracting muscle through movements such as lowering a dumbbell in bicep curls, sitting on a chair slowly or walking downstairs. Earlier studies have shown that this approach is more effective at growing muscle than concentric exercises that involve shortening muscle through movements like lifting a dumbbell or walking up stairs.
Ultimately, these findings challenge conventional rehabilitation methods. Yet they could be a boon for partially immobilized stroke patients and individuals suffering from various injuries, according to Ken Nosaka, a professor at the university’s School of Medical and Health Sciences.
“I think this could change the way we approach rehabilitation for people who have temporarily lost the use of one arm or one leg,” he explained. More importantly, Nosaka added that “by starting rehab and exercise in the uninjured limb right away, we can prevent muscle damage induced by exercise in the other limb and also build strength without moving it at all.”
The university’s research focused on 30 participants who had one arm immobilized for a minimum of eight hours a day for four weeks. This group was divided into three subgroups. One group didn’t exercise, a second group engaged in a mix of eccentric and concentric exercise and the third section performed only eccentric exercises. In a somewhat surprising result, Nosaka reported that the group who used a heavy dumbbell to perform only eccentric exercise on their active arm showed an increase in strength and a decrease in muscle atrophy, or wastage, in their immobilized arm.
Noting the “powerful cross-transfer effect” of this focused eccentric exercise, he added that the approach also had an extremely positive impact on muscle wastage in their limp arm.
“This group also had just two per cent muscle wastage in their immobilized arm, compared with those who did no exercise who had a 28 per cent loss of muscle,” Nosaka said.
More research is needed to understand why the immobilized limb responded positively to eccentric exercise in an active arm. The next stage of research, in fact, may focus on how eccentric exercise can help improve motor function, movement and fine muscle control that could help stroke, rehabilitation patients and athletes interested in recovery faster from injuries.
