Effects of Different Attentional Focus Strategies on Dynamic Stability and Movement Smoothness During Perturbed Gait: An Optimal Control–Based Analysis in Older Adults With and Without Mild Cognitive Impairment

The aim is to compare optimal movement smoothness and dynamic stability under different attentional strategies in older adults with and without mild cognitive impairment.

Two-group quasi-experimental study with repeated measures. Participants with and without mild cognitive impairment will perform perturbation walking under four attentional conditions. Participants and outcome assessors will be blinded to group status; researchers will not be blinded. Trial phase: not applicable.

After screening, participants will be classified into groups with and without mild cognitive impairment. Each participant will perform perturbation walking and obstacle crossing under four attentional conditions: baseline, internal focus, near external focus, and far external focus. Kinematic data will be collected at the Sport Sciences Laboratory, Yazd University, and analyzed to assess dynamic stability, movement smoothness, and optimal motor control.

Participants will be adults aged 60–80 years who walk independently and will be classified as having or not having mild cognitive impairment. Inclusion criteria are independent walking, no conditions affecting walking or balance, and written informed consent. Exclusion criteria include severe visual/hearing impairment and a severe fall within the previous six months.

Participants will be assessed in two groups: with and without mild cognitive impairment, under four attentional conditions: baseline, internal, near external, and far external focus.

Optimal relative weighting of movement smoothness and dynamic stability in the multi-objective optimal control model; dynamic stability assessed by Margin of Stability (MoS), movement smoothness by linear and angular jerk, and agreement between actual and optimized movement patterns by RMSE.

This study will be conducted with blinding at the level of participants and outcome assessors. Participants will not be informed of their own cognitive status or that of other participants, specifically whether they belong to the cognitively healthy older adults group or the mild cognitive impairment (MCI) group. Due to the nature of the study and the need to provide specific instructions for performing the different attentional conditions, blinding participants to the type of attentional condition is not possible. Outcome assessors and personnel responsible for data processing and analysis will also be blinded to the participants’ group status, and the data will be coded using unique identification codes for analysis. The principal investigator and the researcher responsible for conducting the experimental procedures will not be blinded to participants’ group status because access to this information is necessary for proper implementation of the study protocol. Therefore, blinding in this study will be applied to participants’ cognitive status and to outcome assessment and data analysis, whereas blinding of the principal investigator and the researcher conducting the experimental procedures is not feasible due to the nature of the study protocol.

Data related to the study protocol and statistical analysis plan may be available from the corresponding author upon reasonable request after publication of the study results. Individual participant data, informed consent forms, and identifiable information will not be publicly shared to protect participant confidentiality.

De-identified movement data, including dynamic stability, movement smoothness, and optimal control measures, will be available for sharing after removal of personal identifiers.

Available from 6 months after publication of the study results.

Academic and scientific researchers may request access to the data.

The data may be used for research purposes only, subject to confidentiality and protection of participant identity.

Requests should be submitted to the principal investigator at Yazd University.

Applicants should submit a request describing the research purpose and intended use of the data. Following review and approval by the principal investigator, the de-identified data will be provided to the applicant.