Evaluating physical function and activity in the elderly patient using wearable motion sensors.

Area of Science:

• Biomedical Engineering
• Geriatric Medicine
• Rehabilitation Technology

Background:

• Wearable sensors, particularly inertial measurement units (IMUs), offer objective, valid, and responsive assessment of physical function.
• Applications include gait analysis, stair climbing, and sit-to-stand tests, capturing spatiotemporal and kinematic data.
• Accelerometry in activity monitoring (AM) has focused on energy expenditure and step counts, with specific event detection (e.g., stairs) proving powerful in orthopaedics and geriatrics.

Purpose of the Study:

• To review the utility of wearable motion sensors for evaluating physical function and activity in elderly patients.
• To highlight key parameters and applications in clinical settings, especially in orthopaedics and geriatrics.
• To address the challenges in sensor and parameter selection, advocating for standardization.

Main Methods:

• Review of literature on wearable sensor applications in physical function assessment.
• Analysis of parameters derived from inertial measurement units (IMUs) and accelerometry.
• Discussion of clinimetric properties and clinical relevance of different measures.

Main Results:

• IMUs enable precise measurement of functional tests like gait and sit-to-stand, providing time-to-task, spatiotemporal, and kinematic data.
• Activity monitoring using accelerometry effectively counts specific events and quantifies 'micro-level' activity parameters (e.g., step frequency, sit-stand duration).
• Low cost and ease of use facilitate routine clinical application, but variability in sensor/algorithm choices hinders comparability.

Conclusions:

• Wearable motion sensors are valuable tools for objective physical function assessment in the elderly.
• Standardization of sensors, algorithms, and parameters is crucial for consistent and comparable clinical application.
• Further consensus is needed to optimize the use of these technologies in geriatric and orthopaedic care.