Goal-directed modulation of stretch reflex gains is reduced in the non-dominant upper limb.

Autor: Torell F; Physiology Section, Department of Integrative Medical Biology, Umeå University, Umeå, Sweden., Franklin S; Neuromuscular Diagnostics, Department of Sport and Health Sciences, Technical University of Munich, Munich, Germany., Franklin DW; Neuromuscular Diagnostics, Department of Sport and Health Sciences, Technical University of Munich, Munich, Germany.; Munich Institute of Robotics and Machine Intelligence (MIRMI), Technical University of Munich, Munich, Germany.; Munich Data Science Institute (MDSI), Technical University of Munich, Munich, Germany., Dimitriou M; Physiology Section, Department of Integrative Medical Biology, Umeå University, Umeå, Sweden.
Jazyk: angličtina
Zdroj: The European journal of neuroscience [Eur J Neurosci] 2023 Nov; Vol. 58 (9), pp. 3981-4001. Date of Electronic Publication: 2023 Sep 19.
DOI: 10.1111/ejn.16148
Abstrakt: Most individuals experience their dominant arm as being more dexterous than the non-dominant arm, but the neural mechanisms underlying this asymmetry in motor behaviour are unclear. Using a delayed-reach task, we have recently demonstrated strong goal-directed tuning of stretch reflex gains in the dominant upper limb of human participants. Here, we used an equivalent experimental paradigm to address the neural mechanisms that underlie the preparation for reaching movements with the non-dominant upper limb. There were consistent effects of load, preparatory delay duration and target direction on the long latency stretch reflex. However, by comparing stretch reflex responses in the non-dominant arm with those previously documented in the dominant arm, we demonstrate that goal-directed tuning of short and long latency stretch reflexes is markedly weaker in the non-dominant limb. The results indicate that the motor performance asymmetries across the two upper limbs are partly due to the more sophisticated control of reflexive stiffness in the dominant limb, likely facilitated by the superior goal-directed control of muscle spindle receptors. Our findings therefore suggest that fusimotor control may play a role in determining performance of complex motor behaviours and support existing proposals that the dominant arm is better supplied than the non-dominant arm for executing more complex tasks, such as trajectory control.
(© 2023 The Authors. European Journal of Neuroscience published by Federation of European Neuroscience Societies and John Wiley & Sons Ltd.)
Databáze: MEDLINE
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