Lord van Tasm, Wikipedia, CC-BY-SA-3.0
Background
The ability to move and maintain posture in space is critically dependent on motion and orientation information provided by the vestibular system [Forbes2016]. Whenever we walk, for example, vestibular contributions to muscle activity are modulated throughout the locomotion cycle according to a muscle's involvement in correcting for vestibular disturbances. If, however, we are externally supported during walking, the functional use of these vestibular inputs diminishes and vestibular-evoked responses are not observed [Tisserand2018]. In contrast, much less is known about how vestibular signals contribute to balance during biking and several questions arise. What muscles are actively involved in correcting for balance during bicycling? Is steering control more important than upper body stabilizing mechanisms (i.e. inertia) for keeping the body upright? Does the vestibular control of balance for bicycling vary across the cycling phase? Does the vestibular input to bike balance change with cycling speeds? This project aims to answer these questions (and more!) to establish the working principles of the vestibular control of cycling. First, this project will quantify the activity of muscles believed to contribute to balance control when cycling. Second, a mild electrical stimulus delivered behind the ears to manipulate normal vestibular function [Kwan2019] will be used to track vestibular contributions during cycling. By correlating the stimulus to measured muscle activity we will be able to monitor vestibular contributions throughout the cycling pattern and across conditions. These results will reveal how vestibular signal contribute to our ability to remain upright while cycling.
Approach
- Cycling in varying conditions in an open field and/or laboratory setting while collecting muscle activity using EMG.
- Electrical vestibular stimulation (i.e. currents applied via electrodes behind the ears) will be used to modify the vestibular sensitivity of human subjects.
- We will collaborate with Dept. of Neuroscience at the Erasmus MC to implement the electrical stimulation.
Techniques
The student will develop skills to perform biomechanical and neurophysiology experiments in healthy controls during cycling tasks. This includes the use of hard- and software, data collection and signal analysis, but more importantly the use of creativity, which is essential in hypothesis generation, and for optimal experimental design. In this project the focus will be on unraveling how vestibular sensory feedback contributes to cycling behaviors.
References
| [Forbes2016] | Forbes P.A., Luu B.L., Van der Loos H.F.M., Croft E., Inglis J.T., Blouin J.S. (2016), Transformation of Vestibular Signals for the Control of Standing in Humans, Journal of Neuroscience |
| [Tisserand2018] | Tisserand R., Dakin C.J., van der Loos M., Croft E.A., Inglis T.J., Blouin J.S. (2018), Down regulation of vestibular balance stabilizing mechanisms to enable transition between motor states, eLife |
| [Kwan2019] | Kwan A., Forbes P.A., Mitchell D.E., Blouin J.S., Cullen K.E. (2019), Neural substrates, dynamics and thresholds of galvanic vestibular stimulation in the behaving primate, Nature Communications |
How To Apply
If you would like to apply for this project, please send an approximately half page letter explaining your motivations and interest in the lab and project, CV or resume, a list of courses you've taken, the name of your MSc track, and any other relevant information to j.k.moore@tudelft.nl.