Relationship between bimanual coordination performance and intracortical inhibition
Poster No:
1687
Submission Type:
Abstract Submission
Authors:
Hideki Nakano1, Takayuki Maru1, Naoki Shimizu1, Shin Murata1, Kunihiko Anami2, Teppei Abiko1
Institutions:
1Department of Physical Therapy, Faculty of Health Sciences, Kyoto Tachibana University, Kyoto-shi, Kyoto, 2Department of Rehabilitation, Faculty of Health Sciences, Naragakuen University, Nara-shi, Nara
First Author:
Hideki Nakano
Department of Physical Therapy, Faculty of Health Sciences, Kyoto Tachibana University
Kyoto-shi, Kyoto
Department of Physical Therapy, Faculty of Health Sciences, Kyoto Tachibana University
Kyoto-shi, Kyoto
Co-Author(s):
Takayuki Maru
Department of Physical Therapy, Faculty of Health Sciences, Kyoto Tachibana University
Kyoto-shi, Kyoto
Department of Physical Therapy, Faculty of Health Sciences, Kyoto Tachibana University
Kyoto-shi, Kyoto
Naoki Shimizu
Department of Physical Therapy, Faculty of Health Sciences, Kyoto Tachibana University
Kyoto-shi, Kyoto
Department of Physical Therapy, Faculty of Health Sciences, Kyoto Tachibana University
Kyoto-shi, Kyoto
Shin Murata
Department of Physical Therapy, Faculty of Health Sciences, Kyoto Tachibana University
Kyoto-shi, Kyoto
Department of Physical Therapy, Faculty of Health Sciences, Kyoto Tachibana University
Kyoto-shi, Kyoto
Kunihiko Anami
Department of Rehabilitation, Faculty of Health Sciences, Naragakuen University
Nara-shi, Nara
Department of Rehabilitation, Faculty of Health Sciences, Naragakuen University
Nara-shi, Nara
Teppei Abiko
Department of Physical Therapy, Faculty of Health Sciences, Kyoto Tachibana University
Kyoto-shi, Kyoto
Department of Physical Therapy, Faculty of Health Sciences, Kyoto Tachibana University
Kyoto-shi, Kyoto
Introduction:
Bimanual coordination difficulties in stroke patients manifest in both symmetric and asymmetric movements that are essential for goal-directed tasks (Kim et al., 2020). The control of bimanual coordination involves inhibitory and facilitatory neural circuits in the brain (Jordan et al., 2012). However, the relationship between bimanual coordination of finger opposition movements, an essential function for fine motor tasks, and intracortical inhibition remains poorly understood. Clarifying this relationship may contribute to the development of novel assessment and treatment strategies to improve bimanual coordination in post-stroke rehabilitation. This study aimed to clarify the relationship between bimanual coordination performance, as measured by opposition movements of the thumb and index finger, and intracortical inhibition.
Methods:
Twenty-eight right-handed healthy young adults (mean age: 20.66 ± 0.73 years) participated in this study. Each participant performed two tasks: an in-phase task, in which the thumb and index finger moved symmetrically, and an anti-phase task, in which the thumb and index finger moved asymmetrically (Figure 1A). Each task was performed with eyes closed for 15 seconds. During each task, the coefficient of variation (CV) for the maximum local distance of the right finger movements was measured using a Magnetic Sensing Finger Tap Device (UB-2, Maxell). Intracortical inhibition was assessed using the cortical silent period (CSP) measured by transcranial magnetic stimulation (TMS; MagPro R20, MagVenture). CSP was recorded while participants performed isometric contractions at 15% of their maximal voluntary contraction with the right thumb and index finger using a pinch force sensor (Figure 1B). TMS was applied to the left motor cortex at an intensity of 1.3 times the resting motor threshold, and electromyography (EMG) electrodes were placed on the right first dorsal interosseous muscle. Statistical analysis was performed using SPSS 29.0, with normality confirmed by the Shapiro-Wilk test. Spearman's rank correlation coefficient examined the relationship between CV of local maximum distance and CSP, while paired t-test compared CV values for the in-phase and anti-phase tasks. This study was conducted in accordance with the Declaration of Helsinki, and informed consent was obtained from all participants. This study was approved by the Research Ethics Committee of the affiliated institution (approval number 21-47).
Results:
Statistical analysis showed a significant positive correlation between CSP and CV of local maximum distance in both the in-phase and anti-phase tasks (r = 0.44, p < 0.05; r = 0.46, p < 0.05; Figure 2A). In addition, the CV of local maximum distance was significantly lower in the anti-phase task than in the in-phase task (p < 0.05; Figure 2B).
Conclusions:
The results of this study indicate a relationship between bimanual coordination performance and intracortical inhibition in the motor cortex, suggesting that moderate disinhibition in response to task demands is essential for stable bimanual coordination. The results also indicate that the stability of bimanual coordinated movements is higher in anti-phase tasks than in in-phase tasks, suggesting that alternating finger movements may enhance movement stability by allowing detection and correction of movement errors based on proprioceptive feedback.
Brain Stimulation:
Non-invasive Magnetic/TMS 2
Motor Behavior:
Motor Behavior Other 1
Keywords:
Cortex
Motor
NORMAL HUMAN
Physical Therapy
Transcranial Magnetic Stimulation (TMS)
Other - Bimanual coordination; Finger opposition movements; Intracortical inhibition; Cortical silent period
1|2Indicates the priority used for review
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Healthy subjects only or patients (note that patient studies may also involve healthy subjects):
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Were any human subjects research approved by the relevant Institutional Review Board or ethics panel? NOTE: Any human subjects studies without IRB approval will be automatically rejected.
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Provide references using APA citation style.
Kim, R.K. (2020). Bimanual Coordination Functions between Paretic and Nonparetic Arms: A Systematic Review and Meta-analysis. Journal of Stroke and Cerebrovascular Diseases, 29(2), 104544.