• 한국전문물리치료학회지
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• 제19권3호
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• pp.40-50
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• 2012

The purpose of this study was to investigate the effect of visual feedback on the postural control of stroke patients, by systematically varying conditions of visual feedback [eye-open condition (EO) vs. eye-closed condition (EC)], and base-support (both-side support, affected-side support, and unaffected-side support). In this study, we allocated 41 stroke patients with no damage in the cerebellum and visual cortex who can walk at least 10 meters independently, and 35 normal adults who have no experience of stroke to the control group. Both groups were asked to perform a "sit-to-stand" task three to five times, and their postural control ability was measured and compared in terms of asymmetric dependence (AD) instead of the traditional symmetric index (SI) in the literature. The results showed that although both subject groups maintained better postural control in the EO condition than in the EC condition, the patient group appeared to be more stable in EC than in EO when they were required to perform the task of the support condition given on the affected side. These results implied that visual feedback can impair stroke patients' postural control when it is combined with a specific support condition.

• 대한인간공학회지
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• 제23권4호
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• pp.1-8
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• 2004

The objective of this study is to identify the effects of material position and physical fatigue on postural stability. Ten male subjects participated in this study. After bicycling exercises, their centers of pressure (COPs) were measured under four material handling positions and four excercise levels. The measured COPs were then utilized to calculate postural sway length in each experimental condition. Subjects' postural stability was quantified using the sway length. Results showed that the effect of different material handling position was significant on the postural sway length in both the posterior-anterior axis and the medio-lateral axis. Results also showed that the postural sway length was increased as physical fatigue accumulated, significantly in subject's posterior-anterior axis. The results imply that bearing a material on the back or front with both hands appeared to cause least sway length and instability.

• 대한통합의학회지
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• 제4권4호
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• pp.21-32
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• 2016

Purpose: The purpose of this study was to identify whether task-related circuit exercise program combined with sensorimotor training for 4 weeks could improve the balance and gait in stroke patients. Method: Fifteen stroke patients who had agreed with the study were randomly divided into 3 groups categorized as task-related circuit exercise program combined with sensorimotor training group (experimental group 1, n=5), task-related circuit exercise program group (experimental group 2, n=5), and control subjects performed conventional physical therapy (control group, n=5). The balance and gait were assessed by BT-4 force platform system, Berg Balance Scale, 10meter Walk Test and Smart Step at before training and after training. Wilcoxon signed rank test was used to analyze change before and after intervention in intra-group. Kruskal Wallis H test, Mann-Whitney U test and Bonfferoni correction were used to analyze changes of all variables in inter-groups. Result: The experimental group 1 showed significant improvements in postural sway area, BBS scores, walking velocity and plantar pressures of affected foot, whereas the experimental group 2 showed significant improvements in BBS scores, and the control group were no significantly different in all variables following training. The changes of postural sway area and BBS scores in the experimental group 1 were significantly greater than them of the control group. The changes of postural sway area in the experimental group 1 was significantly greater than that of the experimental group 2. Conclusion: The result of this study suggest the task-related circuit exercise program combined with sensorimotor training is an effective intervention to improve balance and gait in stoke patients.

• Physical Therapy Rehabilitation Science
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• 제4권1호
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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.

• The Journal of Korean Physical Therapy
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• 제11권3호
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• pp.23-36
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• 1999

The very definitions of posture and balance have changed, as has our understanding of the underlying neural mechanisms, In rehabilitation science, there awe at least two different conceptual theories to describe the neural control of posture and balance : the reflex/hierarchical theory and system theory. A reflex/hierarchical theory suggests the posture and balance result from hierarchically organized reflex responses triggered by independent sensory systems. The systems approach suggests that action emerges from an interaction of the individual with the task and environment. That is to say, the systems approach implies that the ability to control our body's position in space emerges from a complex interaction of musculoskeletal and neural systems, collectively referred to as the postural control system. The specific organization of postural systems determined both by the functional task and the environment in which it is being performed, The postural control system is divided into three basic functional components for assessment : 1) musculoskeletal components, 2) motor coordination components, and 3) sensory organization components. It is proposed that a systemic functional understanding of human balance is critical to effective programs for balance rehabilitation. Thus, this article briefly reviews the basic functional components to consider in designing treatment plan and for the benefit of the balance assessment.

• The Journal of Korean Physical Therapy
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• 제21권4호
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• pp.51-56
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• 2009

Purpose: This study examined the difference in the static balance ability according to the visual cues and postural tasks in normal subjects. Methods: Thirty participants (12 male, 18 female; mean age $24.63\pm1.43$ years) stood barefoot on a force platform in a one-legged stance, tandem Romberg stance and tandem Romberg with neck extension stance with a visual cue open and closes. The static balance was assessed by the center of pressure (CoP), surface electromyography root mean square (RMS) of the leg muscles according to the stance position. Results: In the CoP tests, the difference in the unit path length and circumference area was affected by the visual cue according to the stance posture (p<0.01). In the RMS tests, the difference in the tibialis anterior and medial gastrocnemius muscle was affected by visual cue in accordance with the stance posture (p<0.01). Conclusion: The visual cue and postural task affect the balance ability in normal subjects. Therefore, this study provides clinical evidence that the balance and postural control can be improved. Therapeutic intervention, such as an obstacle course, and a lower leg muscle performance program with a change in the base of support can affect the balance and postural control.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.1066-1069
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• 2002

Dynamic postural control varies with the environmental context, specific task and intentions of the subject. In this paper, dynamic postural control against forward-backward perturbations of a platform was estimated using tri-axial accelerometers and a force plate. Ten young healthy volunteers stood upright in comfortable condition on the perturbation system which was controlled by an AC servo motor. With anterior-posterior perturbations, movements of ankle, knee and hip Joints were obtained by tri-axial accelerometers. and ground reaction forces with corresponding displacements of the center of pressure(CoP) by the force plate. The result showed that the ankle moved first and the trunk forward, which implies that the mechanism of the dynamic postural control in forward-backward perturbations, occurred in the procedure of the ankle, the knee and the hip. Knee flexion and hip extension in the period of acceleration, constant velocity and deceleration phase is very important fur the balance recovery. These responses depends on the magnitude and timing of the perturbation. From the present study the accelerometry-system appears to be a promising tool for understanding kinematic accelerative In response to a transient platform perturbation. A more through understanding of balance recovery mechanism may aid in designing methods for reducing falls and the resulting injuries.

• 대한물리의학회지
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• 제3권3호
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• pp.169-176
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• 2008

Purpose : Tandem stance is a clinical measure of standing balance considered to assess postural steadiness in a heel-to-toe position by a temporal measurement. The aim of this study is to investigate postural steadiness and to explore the weight distribution between legs during 25s of quiet stance and tandem stance(right foot was leading) in healthy young adults. Methods : 107 healthy young adults(mean age 21.1 years) are participated. Weight distribution beneath both feet and sway distance were recorded while the subjects performed 25s of quiet stance and tandem stance. Results : Subjects placed more weight on the rear leg in tandem stance and on the left foot in quiet stance. So, quiet stance and tandem stance is not a task for equal weight bearing. Subjects show larger sway distance in anteroposterior direction of tandem stance than quiet stance. Conclusion : The results of this study will be useful to researchers and clinicians using tandem stance measures to evaluate postural steadiness and to predict fall. The results suggest that tandem stance is useful to treat of weight distribution and to improve of balace in elderly adults and stroke patients.

• 대한물리의학회지
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• 제15권3호
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• pp.29-41
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• 2020

PURPOSE: The aim of this study was to provide evidence for the treatment of Forward Head and Rounded Shoulder Posture (FHRSP) using posture correction exercises by comparing muscle activity and onset time around the neck and shoulder area during an arm elevation task. METHODS: The subjects were divided into FHRSP (21 persons) and non-FHRSP (19 persons) groups to measure muscle activity and onset time of muscle contraction. Wireless surface electromyography was used to assess the muscle activity and onset time of the right and left sternocleidomastoid (SCM), splenius capitis, anterior deltoid, middle deltoid, serratus anterior, upper trapezius, pectoralis major, and infraspinatus during an arm elevation task. After the pre-measurement, the participants performed the postural correction exercises, and then the post-measurement was conducted. RESULTS: After the posture correction exercises, there were significant differences in the muscle activity and onset time of all muscles in the FHRSP group. The results of the comparison of the muscle onset time during an arm elevation task demonstrated that after the postural correction exercises, the muscle onset time was significantly reduced in the right and left SCM and left splenius capitis, but there were no significant changes in the onset time of other muscles. CONCLUSION: The results of this study help us understand the change in muscle activities and muscle contraction onset time in a person with FHRSP when lifting the arm and suggest the relevant basis to apply the posture correction exercise in clinical settings.

• Safety and Health at Work
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• 제10권3호
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• pp.321-326
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• 2019

Background: Performing cognitive tasks and muscular fatigue have been shown to increase muscle activity of the lower extremity during quiet standing. A common intervention to reduce muscular fatigue is to provide a softer shoe-surface interface. However, little is known regarding how muscle activity is affected by softer shoe-surface interfaces during static standing. The purpose of this study was to assess lower extremity muscular activity during erect standing on three different standing surfaces, before and after an acute workload and during cognitive tasks. Methods: Surface electromyography was collected on ankle dorsiflexors and plantarflexors, and knee flexors and extensors of fifteen male participants. Dependent electromyography variables of mean, peak, root mean square, and cocontraction index were calculated and analyzed with a $2{\times}2{\times}3$ within-subject repeated measures analysis of variance. Results: Pre-workload muscle activity did not differ between surfaces and cognitive task conditions. However, greater muscle activity during post-workload balance assessment was found, specifically during the cognitive task. Cognitive task errors did not differ between surface and workload. Conclusions: The cognitive task after workload increased lower extremity muscular activity compared to quite standing, irrespective of the surface condition, suggesting an increased demand was placed on the postural control system as the result of both fatigue and cognitive task.