Assessment of dynamic stability and identification of key tasks, inertial sensors, and parameters in patients with bilateral and unilateral vestibulopathy: investigation in a semi-standardized environment

Monitoring the functional status of patients with bilateral vestibulopathy (BV) or unilateral vestibulopathy (UV) in an ecological environment remains a challenge, as current tests are performed in specialized laboratories and do not reflect patients’ limitations and symptoms. This study aimed to evaluate the overall movement patterns of patients using inertial measurement units (IMU) in a semi-standardized environment that replicated daily life situations. Nineteen BV patients, 20 UV patients, and 20 healthy subjects were recruited to perform 15 daily-living tasks. The intensity, smoothness, and stabilization parameters were calculated from IMU data. The relevant tasks were selected on the basis of their duration and perceived difficulty. Principal component analysis (PCA) was used to identify the variables that contributed most to the variance in the dataset, and their discriminating ability between groups was assessed using Kruskal-Wallis tests. Tasks that minimize or deprive compensatory sensory inputs (e.g., proprioceptive or visual cues), thereby increasing reliance on vestibular information, proved to be the most discriminative between patients with bilateral vestibulopathy and healthy subjects with IMUs placed on the feet (e.g., putting on pants, walking on uneven ground, on inclined plane, in the dark, on a wood beam, or with head turns). BV and UV patients exhibited reduced movement intensity compared to healthy subjects, which can reflect different compensatory stabilisation strategies. This study demonstrated the feasibility of objective functional status assessment using IMUs and provides a basis for the development of rapid clinical protocols, to assess outcomes for rehabilitation therapies.