Muscle co-contraction of the forearm is increased in response to temporal uncertainty during a dynamic stabilization task
File(s)
Accepted version
Author(s)
Steadman, Nathan
Tan, Huiling
Vaidyanathan, Ravi
Haar, Shlomi
Type
Conference Paper
Abstract
Modulation of joint stiffness through selective co-contraction of antagonist muscles is integral to adaptive motor control, vital for both feedforward modelling of environmental demands as well as adaptation to proprioceptive feedback. Here, we challenged healthy individuals to stabilize the position of a mechanized wrist exoskeleton under both temporally predictable and temporally uncertain perturbation schedules. The impact of this dynamic stabilization task was then assessed through subsequent cued voluntary flexion and extension movements. Participants demonstrated significantly increased muscular co-contraction in response to uncertain scheduling that remained stable over repeated task exposures. This increased co-contraction was correlated with a delay in reaction time when cued to voluntary movement following the dynamic stabilization task. These results highlight the significant impact of temporal uncertainty on muscle co-contraction and demonstrate how the existing motor context influences subsequent movement. Clinical Relevance - Developing insight into joint stiffness modulation and the role of muscle co-contraction in healthy motor control helps to better understand the deficiencies in these processes present in clinical conditions such as Parkinson’s disease (PD). Focusing this understanding on wrist movement is specifically relevant due to clinical assessments of PD commonly utilizing passive mobilization of the wrist as a central assessment of clinical rigidity. As such, understanding how different dynamics modulate wrist stiffness can guide the improvement of current clinical techniques and potentially inspire new diagnostic and therapeutic approaches.
Date Issued
2025-12-03
Date Acceptance
2025-04-08
Citation
Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), 2025
ISSN
2694-0604
Publisher
IEEE
Journal / Book Title
Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC)
Copyright Statement
Copyright © 2025 IEEE. This is the author’s accepted manuscript made available under a CC-BY licence in accordance with Imperial’s Research Publications Open Access policy (www.imperial.ac.uk/oa-policy)
License URL
Source
47th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC 2025)
Publication Status
Published
Start Date
2025-07-14
Finish Date
2025-07-18
Coverage Spatial
Copenhagen, Denmark
Date Publish Online
2025-12-03