State-of-the-Art: Gait and balance parameters are most often collected under controlled conditions in the lab or the hospital. These assessments reflect mainly functional capacity, compared to the assessments performed in the home environment that mainly provide information about functional performance. The overlap between functional capacity and functional performance is not yet clearly defined, and for our understanding of daily (“ecologically”) relevant deficits, a detailed understanding of the (degrees of) relationships between the respective quantitative parameters of functional capacity and functional performance is indispensable.

Approach: We will establish the relationship between gait and balance parameters using instrumented protocols in the lab and long-term monitoring during daily activity in older and frail persons. Data will be collected with a validated and simple-to-use system developed by our company in collaboration with the École polytechnique fédérale de Lausanne, consisting of 4 sensors with each 3D gyroscopes, 3D accelerometers, 3D magnetometers and 1 barometric pressure sensor. They are fixed on the feet, near the centre of mass, and on the wrist. The approach will be based on estimating a subset of the most relevant spatio-temporal parameters on long-term data sets from motion sensors. The study will evaluate the aspects of repeatability (test-retest) and sensitivity to factors such as the duration and time of the test. The estimation model will be based on context analysis and data fusion algorithms and machine learning approaches, and will include personal, environmental and functional levels based on the ICF model. The eventual aim is the definition of the minimal wearable motion sensor configuration and the optimal sensor placement that leads to optimal assessment of daily activity, with particular focus to achieve reliable estimates of the gait and balance test outcome measures as assessed in the lab.