New Australian research reveals why our walks slow down and become more tiring as we age, suggesting the body prioritizes stability over efficiency to prevent falls.
A study led by Flinders University and the University of Canberra found that aging prompts a "safety-first" approach to walking. This strategy emphasizes staying upright and stable, which can lead to older adults fatiguing faster and increasing their risk of falling.
Researchers analyzed movement data from 107 adults aged 26 to 86, identifying subtle but significant age-related shifts in how ankle muscles operate during each step. Dr. Cody Lindsay, a lead author, explained that the ankle plays a crucial role in both balance and forward propulsion. "As we get older, the body starts to favor stability over efficiency," Dr. Lindsay stated. "That helps keep us upright, but it also makes walking more of an effort."
The study observed that older adults tend to activate opposing ankle muscles simultaneously, a phenomenon called co-contraction. This stiffens the ankle joint, enhancing stability upon ground contact. However, Dr. Lindsay noted this comes at a price: "Stiffening the joint makes walking safer, but it also means the muscles are working harder without generating as much forward movement." Consequently, older participants showed reduced push-off power, shorter strides, and slower walking speeds.
Associate Professor Maarten Immink, a co-author, added that this reflects a broader shift in the nervous system’s movement management with age. "The nervous system adopts a safety-first approach, compensating for age-related changes by favoring stability over performance," he said. These adjustments can also contribute to increased fatigue, make longer walks challenging, and diminish the ability to recover from stumbles, which is a major factor in falls among older individuals.
The findings also suggest exercise interventions should focus not just on strength, but also on balance, coordination, and how muscles work together. Dr. Lindsay recommended that for older Australians, simple activities like regular physical activity, balance exercises (such as tai chi), lower-leg strengthening, and coordination challenges can make a difference. "Staying active is one of the most important things people can do, and small, consistent exercises can help you stay confident, mobile and independent for longer," he concluded.
