# Neural control of anticipatory braking and lateral balance predicts fall risk in older adults: BMI-dependent mechanisms

## TL;DR

The study shows that neural control of gait, specifically anticipatory braking and lateral balance, predicts fall risk in older adults, with effects depending on body mass index.

## Contribution

The study identifies BMI-dependent mechanisms in how gait control predicts falls in older adults.

## Key findings

- Fallers had more negative DCEL and higher VZCC compared to non-fallers.
- DCEL predicted falls only in normal weight individuals, while VZCC predicted falls across all BMI levels.
- BMI-stratified assessments are important for fall risk prediction.

## Abstract

Falls are a leading cause of disability among older adults, and neural control is increasingly recognized as a critical risk factor. In this prospective cohort study, we investigated whether deceleration during terminal swing (DCEL), and medial-lateral velocity zero crossing count (VZCC), reflecting anticipatory braking and lateral balance control, predict future falls, and whether body mass index (BMI) moderates these associations. A total of 380 older adults were assessed and stratified by BMI (overweight: ≥ 25 kg/m2).

Fallers (n = 68) and non-fallers (n = 312) were identified prospectively over a 24-month follow-up period. Gait was measured using inertial measurement units (IMUs) during 14-meter walks.

Compared to non-fallers, fallers were older (75.1 ± 4.31 vs. 73.4 ± 4.51 years, p = 0.002), had more prior falls, more negative DCEL values (−10.57 ± 15.61 vs. -5.08 ± 16.39 cm/s, p = 0.010), and higher VZCC (4.96 ± 2.59 vs. 4.29 ± 1.31, p = 0.023). In multivariate models, age, prior falls, DCEL, VZCC, and the BMI × DCEL interaction predicted fall risk. DCEL predicted falls only in individuals with normal weight (OR = 0.533, 95% CI = 0.368–0.770, p = 0.001), whereas VZCC predicted falls across all BMI levels. Gait parameters reflecting neural control predict fall risk, with effects moderated by BMI.

Anticipatory braking control is critical for individuals with normal weight, whereas lateral instability elevates fall risk regardless of BMI. These findings highlight the value of BMI-stratified fall assessments and targeted interventions.