# Depth Sensor-Based Instrumentation of the Fukuda Stepping Test: Reliability and Clinical Associations in Older Adults

## TL;DR

A depth sensor can reliably measure movement during a stepping test in older adults, and trunk movement is linked to cognitive and physical health factors.

## Contribution

The study introduces a markerless depth-sensing method for the Fukuda Stepping Test with clinical associations in older adults.

## Key findings

- Depth sensor-based Fukuda Stepping Test showed moderate-to-good reliability for most kinematic parameters.
- Trunk flexion and rotation correlated with cognitive function, physical activity, balance, and quality of life.
- Upper trunk rotation was linked to functional mobility measures, while displacement metrics had limited clinical relevance.

## Abstract

What are the main findings?
Depth sensor-based instrumentation of the Fukuda Stepping Test demonstrated moderate-to-good test–retest reliability for most segmental kinematic parameters in older adults.Trunk flexion and rotational kinematic parameters showed clinically meaningful associations with cognitive function, physical activity, balance performance, and quality of life.

Depth sensor-based instrumentation of the Fukuda Stepping Test demonstrated moderate-to-good test–retest reliability for most segmental kinematic parameters in older adults.

Trunk flexion and rotational kinematic parameters showed clinically meaningful associations with cognitive function, physical activity, balance performance, and quality of life.

What are the implications of the main findings?
Markerless depth-sensing technology provides objective and clinically relevant information beyond conventional Fukuda Stepping Test outcomes.Segmental kinematic parameters, particularly trunk flexion, may serve as practical indicators for multidomain functional assessment and fall-risk screening in older adults.

Markerless depth-sensing technology provides objective and clinically relevant information beyond conventional Fukuda Stepping Test outcomes.

Segmental kinematic parameters, particularly trunk flexion, may serve as practical indicators for multidomain functional assessment and fall-risk screening in older adults.

This study evaluated the test–retest reliability of a depth sensor-based Fukuda Stepping Test and examined associations between sensor-derived kinematic parameters and established clinical outcomes in older adults. Eighty-six community-dwelling older adults (mean age 70.3 ± 4.7 years) performed an eyes-closed stepping task monitored by a Microsoft Kinect v2 sensor. Clinical assessments included the Berg Balance Scale, Timed Up and Go test, Five Times Sit-to-Stand, Montreal Cognitive Assessment, International Physical Activity Questionnaire, and WHOQOL-OLD. Test–retest reliability was assessed using intraclass correlation coefficients in a randomly selected subgroup. Reliability estimates varied across parameters, with temporal and displacement-based measures demonstrating more consistent agreement across sessions, whereas selected angular variables showed greater variability. Correlation analyses identified statistically significant associations between trunk kinematic changes and clinical measures, with effect sizes generally ranging from weak to moderate magnitude. Upper trunk rotation was associated with functional mobility measures, while traditional displacement-based metrics demonstrated limited clinical relationships. These findings support the feasibility of markerless depth-sensing technology for objective quantification of movement during the Fukuda Stepping Test and highlight the potential contribution of segmental kinematic parameters to multidimensional functional assessment in older adults.