Tactile feedback from the foot sole has been shown to play an important role in balance and gait. However, feedback is impaired in ageing due to fiber loss and mechanical changes in the skin, leading to increased sway, unsteady gait, and risk of falling. The precise nature of the age-related changes in the feedback signal are currently unknown, and how tactile information is used more generally by the brain to aid in walking and balance is unclear.
Through a combination of experimental and computational work, this project aims to establish how biomechanical and neurological factors, brought about by ageing, change the tactile feedback sent to the brain. Results will pave the way for mitigating and restoring sensory inputs, targeting the main sources of impairment, which are likely to differ from person to person.
Using sensorized in-soles the student will measure the pressure distribution on the foot sole during standing and walking in participants across different age ranges. Neural activity in the nerve can then be reconstructed using a novel simulation of peripheral tactile responses, which will be validated against electrophysiological recordings, obtained by experimental collaborators at the University of Guelph, Canada. The student will measure mechanical aspects of the skin (such as hardness) to assess biomechanical age-related changes and their influence on the tactile signal. Balance and gait will be assessed by measuring sway using inertial sensors. Finally, neural information will be correlated with performance measures to determine the impact of ageing on the quality of tactile feedback.
This highly interdisciplinary project would suit students with a computational or engineering background. For questions about the project, please contact Dr Hannes Saal in the first instance. The work will take place in a vibrant and interdisciplinary research hub: INSIGNEO Institute for in silico Medicine, and Sheffield Robotics, both co-located in the Pam Liversidge Building at the University of Sheffield, and sharing research laboratories and student spaces.
Dr Hannes Saal, Department of Psychology, https://www.sheffield.ac.uk/psychology/staff/academic/hannes_saal
Prof Claudia Mazza, Department of Mechanical Engineering, https://www.sheffield.ac.uk/mecheng/staff/cmazza
Benefits of being in the DiMeN DTP:
This project is part of the Discovery Medicine North Doctoral Training Partnership (DiMeN DTP), a diverse community of PhD students across the North of England researching the major health problems facing the world today. Our partner institutions (Universities of Leeds, Liverpool, Newcastle and Sheffield) are internationally recognised as centres of research excellence and can offer you access to state-of the-art facilities to deliver high impact research.
We are very proud of our student-centred ethos and committed to supporting you throughout your PhD. As part of the DTP, we offer bespoke training in key skills sought after in early career researchers, as well as opportunities to broaden your career horizons in a range of non-academic sectors.
Being funded by the MRC means you can access additional funding for research placements, international training opportunities or internships in science policy, science communication and beyond. See how our current DiMeN students have benefited from this funding here: http://www.dimen.org.uk/overview/student-profiles/flexible-supplement-awards
Further information on the programme can be found on our website: http://www.dimen.org.uk/
Saal HP, Delhaye BP, Rayhaun BC, Bensmaia SJ. Simulating tactile signals from the whole hand with millisecond precision. Proceedings of the National Academy of Sciences. 2017;114: 201704856–201704856.
Strzalkowski NDJ, Peters RM, Inglis JT, Bent LR. Cutaneous afferent innervation of the human foot sole: what can we learn from single-unit recordings? J Neurophysiol. 2018;120: 1233–1246.
Hannah I, Sawacha Z, Guiotto A, Mazzà C. Relationship between sagittal plane kinematics, foot morphology and vertical forces applied to three regions of the foot. International Biomechanics. 2016;3: 50–56.