Information about task duration influences energetic cost during split-belt adaptation and retention of walking patterns post-adaptation

by Samantha Jeffcoat, Adrian Aragon, Andrian Kuch, Shawn Farrokhi, Andrew Hooyman, Russell Johnson, Natalia Sanchez

Studies of locomotor adaptation have shown that adaptation can occur in short bouts and can continue for long bouts or across days. Information about task duration might influence the adaptation of gait features, given that task duration influences the time available to explore and adapt the aspects of gait that reduce energy cost. We hypothesized that information about task duration and frequency of updates influences adaptation to split-belt walking based on two competing mechanisms: individuals anticipating a prolonged adaptation period may either (1) extend exploration of energetically suboptimal gait patterns, or (2) adapt toward a more energy-efficient pattern earlier to maintain an energetic reserve. We tested three groups: N = 19 participants received minute-by-minute updates during a 10-minute adaptation duration (True group), N = 19 participants received no updates during a 10-minute adaptation duration and were misled to expect a prolonged 30-minute adaptation duration (False group), and N = 14 participants received one update halfway through a 10-minute adaptation duration (Control group). We measured step length asymmetry, leg work, and metabolic cost. Our results partially supported our hypothesis but did not confirm the underlying mechanisms. While step length asymmetry did not differ significantly between groups during adaptation, the True group generated a more effortful gait pattern with a greater increase in metabolic cost and higher work with the slow leg. Additionally, the True group showed no association between the different adapted gait variables such as step length asymmetry and metabolic cost, contrary to the Control and False groups. Finally, we observed that the False group showed greater retention of the split-belt aftereffects than the Control and False groups. Thus, adapted locomotor and energetic patterns are influenced by information about task duration, indicating that Information about task duration should be controlled for, or can be manipulated to elicit different efforts during adaptation.

Prevention and Early Delirium Identification Carer Toolkit (PREDICT): A Study Protocol for a Stepped‐Wedge, Cluster Randomised Controlled Trial

ABSTRACT

Background

Delirium, a common, serious and often preventable complication in older hospitalised adults, contributes to significant health and social care costs. Carers are uniquely positioned to identify early signs and support delirium prevention. The Prevention & Early Delirium Identification Carer Toolkit (PREDICT), a novel model of care designed to educate carers about delirium management and prevention strategies, enables them to actively participate in the care and recovery of their person. Developed through a comprehensive literature review, a co-designed eDelphi and pilot study, PREDICT demonstrated acceptability and feasibility.

Aims

To evaluate the effectiveness, implementation and cost-benefit of a PREDICT in hospital settings.

Method

A stepped-wedge cluster randomised controlled trial (SW-cRCT), consisting of a cohort study, healthcare service evaluation, and process evaluation. The study will assess carer and staff knowledge of delirium, carer care giving stress, health service outcomes (e.g., incidence, length of stay, readmissions) and cost-benefit.

Discussion

PREDICT is a scalable, person-centred approach that supports both patients and carers, with the potential to embed best-practice delirium management into routine healthcare.

Public and Patient Involvement

This study was developed in consultation with older adults, carers and healthcare staff. Two consumer representatives joined the project steering committee and contributed to shaping the research question, refining the study protocol and selecting outcome measures relevant to families and healthcare staff. Carers were involved in reviewing participant information sheets and the PREDICT website, providing feedback to ensure clarity and accessibility. Results will be shared with participants and the wider community through plain-language summaries and public presentations.

Trial Registration

Australian and New Zealand Clinical trial: ACTRN12625000705482 registered on the 3rd of July 2025