# Treadmill perturbation-based balance training to prevent unrecovered falls in fall-prone older adults with and without cognitive impairment: protocol for the multi-center randomized controlled TRAIL study

## TL;DR

This study tests if treadmill balance training can help older adults, including those with cognitive issues, avoid falls that leave them unrecovered.

## Contribution

The study introduces a novel treadmill-based perturbation training protocol for fall-prone older adults, including those with cognitive impairment.

## Key findings

- The TRAIL study will assess if treadmill perturbation training reduces unrecovered falls in older adults.
- Results may provide evidence for a low-volume balance training approach for high-risk populations.
- Proxy reporting will be used to improve fall data accuracy in participants with cognitive impairment.

## Abstract

Approximately one-third of older adults fall each year, most often due to slips or trips. Fall incidence is even higher in those with cognitive impairment (CI). Among older adults who fall, about 50% are unable to get up without assistance. Such unrecovered falls are particularly critical, as they are linked to prolonged lying periods, an increased risk of medical complications, and mortality. As unrecovered falls require third-party assistance, they offer an opportunity to incorporate proxy information into fall reporting to reduce recall bias. Perturbation-based balance training (PBT) aims to improve recovery reactions in response to balance disturbances such as slips and trips and thereby prevent falls. This task-specific approach has shown promise in reducing falls in low-risk older adults. However, its efficacy in high-risk populations, especially in participants with CI, remains largely unknown. The primary aim of the TRAIL study is to evaluate the efficacy of treadmill PBT in reducing unrecovered falls among fall-prone older adults with and without CI.

In this multi-center, assessor-blinded, randomized controlled parallel-group trial, 396 older adults (≥ 70 years) at risk of falling (≥ 40% prospective fall risk, Timed Up and Go ≥ 10 s) will be assigned (1:1) to receive nine sessions of either treadmill PBT or conventional treadmill training (CTT) over three weeks. The primary outcome is the incidence of unrecovered falls within twelve months post-intervention, tracked via monthly fall calendars, phone interviews, proactive reporting, and proxy information. Secondary outcomes include other fall-related outcomes (e.g. total falls, injurious falls, falls per physical activity), physical capacity and activity, psychological status, and cognitive functioning. Assessments will be conducted at baseline, post-intervention, as well as six and twelve months after the intervention. Primary analyses will follow the intention-to-treat principle.

Treadmill PBT is expected to reduce unrecovered falls by ≥ 50% over twelve months, compared to CTT. If effective, the low-volume PBT approach can serve as an important treatment option for the rapidly growing group of fall-prone older adults, especially those with CI, for whom evidence-based strategies for fall prevention remain limited.

Prospectively registered at ClinicalTrials.gov (NCT06652828). First posted: 2024-10-22, last update posted: 2025-05-14.

The online version contains supplementary material available at 10.1186/s12877-025-06599-w.