Smartphone-Based Sit-to-Stand Analysis for Mobility Assessment in Middle Age.

Area of Science:

• Gerontology and Rehabilitation Science
• Biomedical Engineering and Wearable Technology

Background:

• Mobility decline is a concern in middle age, necessitating sensitive assessment methods.
• Traditional mobility tests may have a ceiling effect, limiting detection of subtle changes.
• Smartphone accelerometry offers a potential tool for objective mobility assessment.

Purpose of the Study:

• To investigate the utility of smartphone-based accelerometry during sit-to-stand (STS) tests for detecting subtle mobility changes in middle-aged adults.
• To compare STS performance on a standard chair versus a cushioned sofa.

Main Methods:

• Participants (young, middle-aged, older adults) performed the 5-times STS test on a chair and sofa.
• A smartphone accelerometer measured lower-limb muscle power, maximal vertical velocity (MVV), transition duration (SiToSt), and repetition variability.
• Dynamic time warping was used to analyze repetition variability.

Main Results:

• Middle-aged adults exhibited reduced lower-limb muscle power and MVV compared to young adults, particularly on the sofa.
• Subtle differences in MVV and SiToSt duration were observed between middle-aged and young adults only on the sofa.
• Middle-aged adults showed less repetition variability than older adults on the chair.

Conclusions:

• Smartphone-based accelerometry during STS tests can identify subtle mobility declines in middle age.
• The findings suggest this technology can serve as a valuable screening tool for early mobility deterioration.
• Assessment on varied surfaces, like a sofa, may enhance the detection of age-related mobility changes.