• The Journal of Korean Physical Therapy
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• v.29 no.3
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• pp.135-141
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• 2017

Purpose: This study was to identify the anticipatory postural adjustment (APA) mechanism which is represented by the onset time of trunk muscles and the displacement of the center of pressure (COP) according to the different base of support (BOS) during upper extremity movement. Methods: Thirty healthy subjects (14 males, 16 females) participated in this study. The movement was performed for 10 trials during each of various BOS (shoulder - width double leg stance, narrow base double leg stance, tandem stance, non-dominant single leg stance) at the 1.2 Hz frequency. Electromyography was used to measure muscle onset time and biorescue was used to measure characteristics of the displacement of COP. Surface bipolar electrodes were applied over the right deltoid anterior, right latissimus dorsi, both rectus abdominis, both internal oblique and both erector spinae. The data were analyzed by repeated one-way ANOVA and Duncan's post hoc test. Results: The study has revealed following. There were significant differences with muscle onset time in each BOS (p<0.01). There were significant differences in characteristics of the COP in each BOS (p<0.01). Conclusion: The study found that the more narrowed the basis requires the more rapid anticipatory postural control in contralateral postural muscle when the upper extremity movement is performed.

• Physical Therapy Rehabilitation Science
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• v.4 no.1
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• pp.44-48
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• 2015

Objective: The purpose of this study was to investigate the relationship between anticipatory postural adjustment (APA), single task, dual tasks and physical performances. The trunk muscles of APA consist of bilateral erector spinae (ES) and bilateral internal oblique (IO) adnominal muscles, during rapid stepping with the affected or unaffected leg in a sitting posture. Design: Cross-sectional study. Methods: In patients with chronic stroke, electrodes of surface electromyography (EMG) were attached on the bilateral erector spinae (ES), bilateral internal oblique adnominal (IO), and bilateral rectus femoris (RF) muscles. RF acts as the prime mover. The stroke patients performed hip flexion until $20^{\circ}$ as fast as possible at each leg in a sitting posture according to a visual cue. The visual cue unexpectedly appeared on monitor in front of the stroke patient. The single task was the Timed Up and Go (TUG) test. The dual tasks were the TUGconitive, which increased cognitive capacity, and the TUGmanual task, which had an external focus. Results: All EMG data showed earlier onset latency before the prime mover. In affected leg raising, the onset time of unaffected ES muscle of the stroke patients was correlated with the single and dual tasks (p<0.05). In unaffected leg raising, the onset time of the affected IO muscle was related to all the tasks (p<0.05). Gait speed showed a relationship with the unaffected ES muscle only. Conclusions: The trunk muscles of the bilateral ES and bilateral IO play an important role in APA. The single and dual tasks using TUG test were correlated with the APA s of ES and IO muscles. Dual task by the TUG test is a good measuring tool for reflecting the real life in patients with chronic stroke.