Neural control of locomotion
Group leader: Dr. Alessandro Santuz
PhD students: Victor Munoz-Martel, Leon Brüll
Alumni: Dr. Lars Janshen, Dr. Antonis Ekizos
In the group “Neural control of locomotion” we adopt a multidisciplinary approach to investigate a central topic in neuroscience: movement creation and control. Through an interplay of analytical, computational and experimental methods, we endeavour to improve our understanding of how neural pathways for locomotion are organised. In an attempt to transfer fundamental research findings to daily life, we expand our analyses to locomotion in both steady and unsteady conditions in health and pathology (e.g. multiple sclerosis). We make use of specific devices to create unexpected perturbations during locomotion, such as uneven-surface or actuated treadmills, moving platforms, etc. We believe that putting the central nervous system under stress creates the need for an improved robustness of movement, which can be studied to better understand the underlying control strategies.
Our group is focused on the assessment of the modular control of human walking and running using the concept of muscle synergies (i.e. the control of muscle groups in common pathways). Complementary approaches used in the framework of our projects are: fractal analysis, quantification of the local dynamic stability (maximum Lyapunov exponent), energy cost estimation, analysis of the muscle-tendon unit interaction and assessment of the muscle fascicle behaviour. The team benefits from a variegated expertise. Engineers, sport scientists and mathematicians work together using different tools in the common effort of cracking the mysterious code written in the central nervous system.
Uneven surface treadmill for the study of perturbed locomotion
(Santuz et al. (2018), Sci. Rep. 8, 2740)
Four muscle synergies describe the activity of 13 muscles of the lower limb in the four phases of the running gait cycle.
Selected publications
2022
Santuz, A., Janshen, L., Brüll, L., Munoz-Martel, V., Taborri, J., Rossi, S. & Arampatzis, A. Sex-specific tuning of modular muscle activation patterns for locomotion in young and older adults. PLoS One 17, e0269417 (2022).
2021
Janshen, L., Santuz, A. & Arampatzis, A. Muscle Synergies in Patients With Multiple Sclerosis Reveal Demand-Specific Alterations in the Modular Organization of Locomotion. Front. Hum. Neurosci. 14, (2021).
Munoz-Martel, V., Santuz, A., Bohm, S. & Arampatzis, A. Neuromechanics of Dynamic Balance Tasks in the Presence of Perturbations. Front. Hum. Neurosci. 14, (2021).
2020
Santuz, A., Ekizos, A., Kunimasa, Y., Kijima, K., Ishikawa, M. & Arampatzis, A. Lower complexity of motor primitives ensures robust control of high-speed human locomotion. Heliyon 6, e05377 (2020).
Mileti, I., Serra, A., Wolf, N., Munoz-Martel, V., Ekizos, A., Palermo, E., Arampatzis, A. & Santuz, A. Muscle activation patterns are more constrained and regular in treadmill than in overground human locomotion. Front. Bioeng. Biotechnol. (2020).
Santuz, A. & Akay, T. Fractal analysis of muscle activity patterns during locomotion: pitfalls and how to avoid them. J. Neurophysiol. jn.00360.2020 (2020).
Santuz, A., Brüll, L., Ekizos, A., Schroll, A., Eckardt, N., Kibele, A., Schwenk, M. & Arampatzis, A. Neuromotor Dynamics of Human Locomotion in Challenging Settings. iScience 23, 100796 (2020).
Janshen, L., Santuz, A., Ekizos, A. & Arampatzis, A. Fuzziness of muscle synergies in patients with multiple sclerosis indicates increased robustness of motor control during walking. Sci. Rep. 10, 7249 (2020).
2019
Santuz, A., Akay, T., Mayer, W.P., Wells, T.L., Schroll, A. & Arampatzis, A. Modular organization of murine locomotor pattern in the presence and absence of sensory feedback from muscle spindles. J. Physiol. 597, 3147–3165 (2019).
Munoz-Martel, V., Santuz, A., Ekizos, A. & Arampatzis, A. Neuromuscular organisation and robustness of postural control in the presence of perturbations. Sci. Rep. 9, 12273 (2019).
2018
Santuz, A., Ekizos, A., Janshen, L., Mersmann, F., Bohm, S., Baltzopoulos, V. & Arampatzis, A. Modular Control of Human Movement During Running: An Open Access Data Set. Front. Physiol. 9, 1509 (2018).
Santuz, A., Ekizos, A., Eckardt, N., Kibele, A. & Arampatzis, A. Challenging human locomotion: stability and modular organisation in unsteady conditions. Sci. Rep. 8, 2740 (2018).
Ekizos, A., Santuz, A., Schroll, A. & Arampatzis, A. The Maximum Lyapunov Exponent During Walking and Running: Reliability Assessment of Different Marker-Sets. Front. Physiol. 9, 1101 (2018).
Ekizos, A., Santuz, A. & Arampatzis, A. Short- and long-term effects of altered point of ground reaction force application on human running energetics. J. Exp. Biol. 221, jeb176719 (2018).
2017
Santuz, A., Ekizos, A., Janshen, L., Baltzopoulos, V. & Arampatzis, A. The Influence of Footwear on the Modular Organization of Running. Front. Physiol. 8, 958 (2017).
Santuz, A., Ekizos, A., Janshen, L., Baltzopoulos, V. & Arampatzis, A. On the Methodological Implications of Extracting Muscle Synergies from Human Locomotion. Int. J. Neural Syst. 27, 1750007 (2017).
Ekizos, A., Santuz, A. & Arampatzis, A. Transition from shod to barefoot alters dynamic stability during running. Gait Posture 56, 31–36 (2017).
Janshen, L., Santuz, A., Ekizos, A. & Arampatzis, A. Modular control during incline and level walking in humans. J. Exp. Biol. 220, 807–813 (2017).
2016
Santuz, A., Ekizos, A. & Arampatzis, A. A Pressure Plate-Based Method for the Automatic Assessment of Foot Strike Patterns During Running. Ann. Biomed. Eng. 44, 1646–1655 (2016).