Background: Deficits in vestibular function increase the risk for fall while turning. However, the clinical assessment of turning in patients with vestibular dysfunction is lacking, and evidence is limited that identifies how effective vestibular physical therapy (VPT) is for improving turning performance. Objective: To quantify and compare walking and turning performance during the instrumented timed up and go (TUG) test using inertial measurement units (IMUs) for clinical settings. We investigate novel instrumented TUG parameters for ability to distinguish patients with unilateral vestibular deafferentation (UVD) from control groups, and discriminate the differences in turning parameters of UVD patients following a VPT program.
Methods: We recruited 38 patients following UVD surgery, 26 age-matched Veteran patient (VA) controls with reports of non-vestibular dizziness, and 12 age-matched healthy controls. Individuals were donned with body-worn IMUs and given verbal instructions to complete the TUG test as fast as safely possible. The IMU-instrumented and automated assessment of the TUG test provided component-based TUG parameters, including the novel walking:turning ratio. Among the UVD patients, 19 patients completed an additional instrumented TUG testing after VPT.
Results: The walking:turning time ratio showed that turning performance in pre VPT UVD patients are significantly more impaired than VA patients and healthy controls (p < 0.001). Vestibular rehabilitation significantly improved turning performance and “normalized” their walking:turning time ratio compared to healthy controls (p < 0.001). However, the duration of the straight walking component in UVD patients before VPT was not significantly different as to that after VPT as well as healthy controls.
Conclusions: Our data showed that the IMU-instrumented TUG test can distinguish patients with vestibular deafferentation and objectively quantify the change in their turning performance after surgery. The IMU-based instrumented TUG parameters have potential to quantify the efficacy of VPT and be adopted in the clinic.