PNF and Movement 2022; 20(1): 135-145
Comparison of Lower Extremity Electromyography and Ground Reaction Force during Gait Termination according to the Performance of the Stop Signal Task
Dong-Kyun Koo, PT, MS.1⋅Jung-Won Kwon, PT, PhD.2†
1Department of Public Health Sciences, Graduate School, Dankook University
2Department of Physical Therapy, College of Health and Welfare Sciences, Dankook University
Correspondence to: Jungwon Kown (
Received: April 8, 2022; Revised: April 12, 2022; Accepted: April 13, 2022; Published online: April 30, 2022.
© Korea Proprioceptive Neuromuscular Facilitation Association. All rights reserved.

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Purpose: The purpose of this study was to investigate the association between cognitive and motor inhibition by comparing muscle activity and ground reaction force during unplanned gait termination according to reaction time measured through the stop-signal task.
Methods: Sixteen young adults performed a stop-signal task and an unplanned gait termination separately. The subjects were divided into fast and slow groups based on their stop-signal reaction time (SSRT), as measured by the stop-signal task. Electromyography (EMG) and ground reaction force (GRF) were compared between the groups during unplanned gait termination. The data for gait termination were divided into three phases (Phase 1 to 3). The Mann–Whitney U test was used to compare spatiotemporal gait parameters and EMG and GRF data between groups.
Results: The slow group had significantly higher activity of the tibialis anterior in Phase 2 and Phase 3 than the fast group (p <0.05). In Phase 1, the fast group had significantly shorter time to peak amplitude (TPA) of the soleus than the slow group (p <0.05). In Phase 2, the TPA of the tibialis anterior was significantly lower in the fast group than the slow group (p <0.05). In Phase 3, there was no significant difference in the GRF between the two groups (p >0.05). There were no significant difference between the two groups in the spatiotemporal gait parameters (p >0.05).
Conclusion: Compared to the slow group, the fast group with cognitive inhibition suppressed muscle activity for unplanned gait termination. The association between SSRT and unplanned gait termination shows that a participant’s ability to suppress an incipient finger response is relevant to their ability to construct a corrective gait pattern in a choice-demanding environment.
Keywords: Gait termination, Stop signal task, Electromyography

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