Smart Sock for Monitoring Walking and Supporting Physical Activity in Older Adults: A Family-Supported Feasibility Study

The goal of this randomized feasibility clinical trial is to learn whether a low-cost smart sock and mobile application can be used safely, reliably, and comfortably to support gradual walking activity in adults aged 60 years and older. The smart sock is a research prototype worn with the participant's usual footwear. It records simple walking information, such as step timing and walking rhythm, and sends a summary to a mobile application. The application provides an individual walking plan, asks about perceived effort and symptoms, and shows simple messages about whether the participant should continue, repeat the current level, or pause and seek review. The study will include community-dwelling adults aged 60 years or older who can walk independently, with or without a usual walking aid when this is considered safe. This study does not diagnose medical conditions, predict falls, provide emergency monitoring, or replace medical care. The main questions this study aims to answer are: * Can older adults use the smart sock and application comfortably and complete the planned walking sessions? * Does the smart sock record step events and walking cadence accurately enough for this type of monitoring? * Are the application instructions, safety messages, and optional family-support feature understandable and acceptable to older adults? * Can the study procedures be delivered safely, including device fitting, battery charging, walking progression, and reporting of symptoms or falls? * What changes are seen over 12 weeks in walking activity and supervised functional assessments? Researchers will compare a smart-sock-supported adaptive walking group with a comparison group receiving a standard individual walking plan. Participants will be assigned to one of the two groups by chance. The smart-sock group will use the device and app, which may adjust the walking plan conservatively when repeated sessions are completed at an acceptable effort and no safety concerns are reported. Participants in this group may choose a trusted family member or helper to receive limited notifications, such as "session completed" or "please check in." Family members will not see sensor data, symptoms, health history, test results, or decisions about walking progression. The comparison group will follow a standard nonadaptive walking plan independently and will not receive the smart sock, individualized app feedback, or study-provided family support. Participants will: * Complete screening, provide informed consent, and take part in a supervised baseline visit. * Complete walking-related assessments at baseline, Week 6, and Week 12, including a 6-minute walk test, Timed Up and Go test, and 30-second chair-stand test. * Follow an individual walking plan for 12 weeks, usually with three to five sessions per week. * In the smart-sock group, wear the smart sock during planned sessions and use the mobile application to record session completion, perceived effort, and any symptoms. * Report falls, near-falls, pain, dizziness, unusual shortness of breath, device discomfort, or technical problems. Participants can stop a walking session at any time. The walking plan will not progress if there are warning symptoms, a fall, high perceived effort, concerning changes in walking information, or a decline at supervised reassessment. The study team may pause, simplify, or review the plan when needed.

Inclusion Criteria: * Aged 60 years or older. * Living in the community (not residing in an institutional care facility). * Able to walk independently, with or without a customary walking aid, when considered safe by the study team. * Insufficiently active or interested in improving regular walking activity. * Has a compatible smartphone or access to a study-supported smartphone. * Able to understand study instructions and use the application independently or with assistance from a participant-selected helper. * Able and willing to provide written informed consent. * Willing to wear the smart sock during planned sessions and complete study assessments and follow-up procedures. Exclusion Criteria: * Chest pain during physical activity or at rest that has not been medically assessed. * Unexplained dizziness, fainting, or loss of consciousness. * Acute lower-limb injury, severe foot pain, or another condition that prevents safe walking. * Unstable medical condition or a condition for which gradual unsupervised walking progression is considered inappropriate. * A fall in the recent period that required medical attention, unless cleared by an appropriate health professional. * Severe cognitive, visual, hearing, or communication difficulty that prevents informed consent, understanding of safety instructions, or safe participation. * Any other condition identified during pre-exercise screening that requires medical review before increasing physical activity.