Ageing walkers trade push-off power for ankle stability

The ankle does two jobs on every step: it keeps you stable when your foot lands, then powers you forward as you push off. Ageing changes both the muscles and tendons around the joint and the nervous system's coordination of them, which can pull those two jobs out of sync. What has been less clear is exactly when in the walking cycle these changes appear, and whether older adults lose power because their muscles weaken or because their control strategy shifts. This study set out to map how ankle muscle activity, joint angles, joint forces and ground reaction forces change continuously with age across the full gait cycle.

Researchers ran a secondary analysis of data from 107 healthy, able-bodied adults spanning ages 26 to 86. Each person walked overground at their own comfortable speed while three-dimensional motion capture tracked their movement, force platforms measured the forces between foot and ground, and surface electromyography recorded activity in two key lower-leg muscles: the tibialis anterior at the front of the shin and the gastrocnemius in the calf. The team then time-normalised each gait cycle and used statistical mapping regressions to test how every phase of the stride changed continuously with age, rather than simply comparing young and old groups.

Increasing age was associated with more simultaneous tensing of the shin and calf muscles during early and mid-stance, and less of it in terminal stance. Older adults showed greater dorsiflexion in late stance and pre-swing, reduced plantarflexion moments in mid-stance, and lower braking and propulsive ground reaction forces. Strikingly, gastrocnemius activity in early stance actually increased with age even as the plantarflexion moments it should produce declined, which the authors interpret as a stabilising motor-control strategy compensating for reduced proprioceptive acuity. In short, the muscles work harder while the joint delivers less.

The findings support the idea that age-related walking decline is not just a matter of weaker muscles but of a changed control strategy, and they pinpoint that the changes are phase-specific rather than uniform across the stride. The authors argue these adaptations maintain stability but reduce mechanical efficiency and propulsion, likely contributing to slower gait, greater fatigue and elevated fall risk. Because everyone was measured once, the study cannot show how any individual's gait evolves over time, nor whether the strategy is reversible. The authors suggest interventions should target neuromuscular timing, phase-specific coordination, proprioception and muscle-tendon function.

If walking feels slower and more tiring with age, this study offers a reason: the body may be quietly prioritising not falling over generating forward drive, stiffening the ankle at the moments of the stride when balance is most at risk. That reframes age-related slowing as partly a control problem rather than purely a strength problem. It is a reason to think that ankle function, balance and the sense of where your foot is in space matter alongside raw muscle for staying mobile. This is a single snapshot study, though, so it describes the pattern rather than proving what fixes it.