Predictive Foot Targeting During Natural Human Walking: Evidence from 556 Community-Dwelling Adults

Background The brain continuously estimates distance and adjusts gait to satisfy foot-placement constraints during everyday walking. While computational neuroscience has long proposed that such locomotor behaviour involves predictive motor control, experimental evidence from large naturalistic populations across varying conditions has been lacking. Methods We observed 556 healthy community-dwelling adults (ages 7–80 years, 49.5% female; education ranging from illiterate to university degree) approaching marked targets at three distances (12 m, 20 m, 30 m; order randomized). Participants were instructed which foot should land at the target but received no guidance on strategy, step-counting, or distance estimation. In a subset (n = 178), the foot specification was changed mid-approach to probe real-time motor adaptability. Success was defined as the specified foot landing within ± 10 cm of target centre, reflecting normal biological variability and permitting late corrective adjustments. Results Overall success rate was 98.1% (547/556 participants achieved > 95% accuracy). Performance showed no dependence on target distance (12 m: 98.2%, 20 m: 98.1%, 30 m: 97.9%; χ² = 0.24, p = 0.89), age (r = − 0.08, p = 0.63), education (F₃,₅₅₂ = 0.18, p = 0.91), or sex (p = 0.82). Mid-course command changes yielded 95.5% success across all change-point timings (ANOVA: p = 0.59), with no performance decline when commands changed late in the approach (> 75% distance covered). Performance reflected robust error reduction rather than exact precomputed accuracy, with successful trials often including small step-length adjustments near the target consistent with late-stage correction. Conclusions These findings demonstrate that neurologically intact adults spontaneously and reliably satisfy a locomotor foot-placement constraint through automatic predictive motor control implemented through continuous adjustment. The scale-invariant accuracy, independence from formal education, and preserved adaptability during mid-course changes suggest reliance on continuous distance estimation and online motor updating rather than explicit calculation or conscious planning. Low performance was strongly associated with identifiable neurological conditions, raising the possibility that this simple walking task may serve as a sensitive observational marker for motor system dysfunction.