• Physical Therapy Rehabilitation Science
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• v.7 no.2
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• pp.83-87
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• 2018

Objective: The purpose of this study was to investigate the relationship between heart rate (HR), self-awareness of exercise intensity (rating of perceived exertion, RPE), and 5-meter walk test (5MWT) of persons affected by stroke during backward walking according to the preferred stride frequency (PSF), PSF+3 and PSF+6 conditions. Design: Cross-sectional study. Methods: A total of 11 persons with stroke (9 males, 2 females) participated voluntarily. All patients underwent backward walking under the PSF, PSF+3, and PSF+6 conditions in underwater and ground environments, and each condition was performed for 5 minutes. The HR, RPE, and walking speeds were measured during walking, and the measured values from underwater and ground environments were compared. Results: The HR and RPE in the ground environment were significantly increased (p<0.05), and although the 5MWT showed an increase in speed, it was not significant. The HR and RPE in the underwater environment were also significantly increased (p<0.05), however, although the 5MWT results was increased, it was not significant. The HR and RPE were significantly increased in the PSF+6 condition (p<0.05). Conclusions: The results of this study showed that backward gait training underwater can provide an appropriate exercise intensity for stroke survivors and suggests that exercises performed in an underwater environment is more effective compared to the ground environment.

• Journal of International Academy of Physical Therapy Research
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• v.1 no.2
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• pp.120-125
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• 2010

The purpose of this study was to compare the effects of treadmill walking in underwater and overground which affects gait and physical function of people who have had a stroke. Twenty people after a stroke who have become hemiplegic over 6 months were participated. Participants were divided into two groups: underwater treadmill group(UTG) and overground treadmill group(OTG). The intervention was done 4 times per weeks for 6 weeks and 1 session lasted for 30 minutes. Gait and physical function elements were measured at baseline, at the middle(3 weeks) and at the end of the intervention(6 weeks). For the elements of gait, walking velocity, affected stance phase, affected weight bearing were assessed. For the elements of physical function, Short Form 8(SF-8) health survey was used. The result of this study showed that both groups improved similarly in walking velocity. However participants in UTG improved more than those in OTG in affected stance phase(p<.05), affected weight bearing(p<.05) and emotional aspect(p<.001). Based on the results of this study, it can be suggested that treadmill walking both in underwater and on the ground can be effective in improving hemiplegic gait and physical function of people who have had a stroke. The result also suggest that the underwater treadmill exercise can be more effective than overground treadmill in restoration of gait in people after stroke.

• Journal of Korean Physical Therapy Science
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• v.16 no.4
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• pp.67-74
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• 2009

Background: This study had been carried out with 20 elderly subjects as its object for about one month from November 3, 2008 to December 14, 2008 in order to observe the effect of Underwater Treadmill on the elderly's walking and balance ability. Methods: Subjects were assigned either experimental group (n=10) or the control group (n=10), experimental group received Underwater Treadmill program (30 min per course, 3days a week for 6weeks). Subjects were assessed for muscle power (Nicolas Manual Muscle Test), balance (Functional Reach Test), gait ability (Time Up and Go, 10M walking test) before experiments and after experiments. Results: The results of this study were as follows; 1. After underwater treadmill exercise, the change of isometric contraction indicated a beneficial increase on lower extremity muscle power of experimental group and functional test of balance function; FRT, TUG indicated beneficial difference between groups. 2. beneficial difference between groups in walking speed of hourly index change of walking function. 3. between muscle power and balance, gait ability, we could find out there's high correlation ship between lower extremity muscle power increasing and balance and gait ability of the elderly. Conclusion: Aerobic exercise using underwater treadmill effects on muscle power strengthening of the elderly, and because of this, increase of lower extremity muscle power is very helpful not only to improvement of balance ability, but also to improvement of gait ability, so it will be used as a physical therapy program on clinic and used as an exercise program for protecting the elderly from falling down very well.

• Journal of the Korean Society of Physical Medicine
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• v.13 no.1
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• pp.89-98
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• 2018

PURPOSE: While underwater, patients with hemiplegia experience unwanted limb flotation on their paretic side due to low muscle mass and high body fat. However, only a limited number of studies support the effectiveness of this practice. Therefore, the purpose of this study was to determine how the balance and walking abilities of patients with hemiplegia due to stroke were affected by wearing an aquatic cuff on their ankles during underwater treadmill walking. METHODS: Twenty stroke patients were divided into an experimental group comprised of 20 patients who would wear an aquatic cuff and a control group comprised of 10 patients without an aquatic cuff. Both groups underwent a six-week intervention for 30 minutes a day three times a week. To evaluate the groups' balance and walking abilities before and after the intervention, the 10 m walking test, timed up go test, Berg Balance Scale, functional reaching test, and the GAITRite system were used. RESULTS: The results of the 10 m walking test, timed up go test, differences between the left and right gait cycles, and functional reaching test showed statistically significant differences in the rates of change between the two groups (p<.05). CONCLUSION: The study results suggest that underwater treadmill training in stroke patients can be more effective when they wear an aquatic cuff on their ankles compared to wearing no aquatic cuff.

• International Journal of Ocean System Engineering
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• v.1 no.4
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• pp.222-229
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• 2011

In this paper, we present the concept and main mission of the Crabster, an underwater walking robot. The main focus is on the modeling of drag and lift forces on the legs of the robot, which comprise the main difference in dynamic characteristics between on-land and underwater robots. Drag and lift forces acting on the underwater link are described as a function of the relative velocity of the link with respect to the fluid using the strip theory. Using the translational velocity of the link as the rotational velocity of the joint, we describe the drag force as a function of joint variables. Generalized drag torque is successfully derived from the drag force as a function of generalized variables and its first derivative, even though the arm has a roll joint and twist angles between the joints. To verify the proposed model, we conducted drag torque simulations using a simple Selective Compliant Articulated Robot Arm.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.8
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• pp.709-717
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• 2013

This paper presents the development of a specialized underwater leg with a manipulator function(convertible-to-arm leg) for the seabed walking robot named CRABSTER200(CR200). The objective functions of the convertible-to-arm leg are to walk on the seabed and to work in underwater for precise seabed exploration and underwater tasks under coastal area with strong tidal current. In order to develop the leg, important design elements including the degree of freedom, dimensions, mass, motion range, joint structure/torque/angular-speed, pressure-resistance, watertight capability and cable protection are considered. The key elements of the convertible-to-arm leg are realized through concept/specific/mechanical design and implementation process with a suitable joint actuator/gear/controller selection procedure. In order to verify the performance of the manufactured convertible-to-arm leg, a 25bar pressure-resistant and watertight test using a high-pressure chamber and a joints operating test with posture control of the CR200 are performed. This paper describes the whole design, realization and verification process for implementation of the underwater convertible-to-arm leg.

• The Journal of Korean Physical Therapy
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• v.31 no.4
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• pp.204-211
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• 2019

Purpose: This study aimed to investigate the effect of progressive speed increase during underwater gait training on stroke patients' balance, gait, and endurance, as well as to compare the effects of underwater gait training and land gait training. Methods: Subjects were randomly allocated into three groups. Underwater gait training group (n=10), land gait training group (n=9) and control group (n=9). The groups performed their respective programs as well as conventional physical therapy 3 times/week for 8 weeks. The patients were assessed before and after the experiment in terms of the Berg balance scale, characteristics of gait, and 6-minute walking test. Results: The beneficial effect perceived in the speed increase underwater gait training (UGT) group was significantly greater than in the groups who were trained with speed increase land gait training (LGT) group, and the control group regarding the following aspects: the Berg balance scale, the affected step length, the affected stride length, and the 6-minute walking test (p<0.05). The LGT group showed a more significant effect on the Berg balance scale, the affected step length, the affected stride length, and the 6-minute walking test (p<0.05), compared to the control group. Furthermore, the UGT group showed a significantly greater effect on the gait speed when compared to the control groupb (p<0.05). Conclusion: This study shows that progressive UGT is effective in improving balance, gait, and endurance in stroke patients. Therefore, we believe that progressive UGT may be used as a method for general physical therapy in patients with stroke.

• Korean Journal of Applied Biomechanics
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• v.29 no.1
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• pp.15-21
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• 2019

Objective: The purpose of this study was to investigate the effects of aqua-noodles on the practice of underwater walking in patients with hemiplegia. Method: After an oral explanation and signing an IRB approved consent form 10 participants ($66.8{\pm}10.75yr$, $165.3{\pm}8.79cm$, $73.6{\pm}46kg$) agreed to participate in this study. Each of the participants was required to walk with the aqua noodles and without the aqua-noodles in a swimming pool. Each participant was asked to walk a distance of 5 m a total of 10 times, 5 with and 5 without the aqua-noodles. The depth of the swimming pool was at 1.3 m, approximately chest height. The following variables were calculated for analysis; height of the knee (m), knee joint ROM ($^{\circ}$), ankle joint ROM ($^{\circ}$), knee joint maximum angular velocity ($^{\circ}/sec$), and ankle joint maximum angular velocity ($^{\circ}/sec$). Results: First, there was a significant increase in time (s) for the maximum knee height to reach as well as the maximum knee height (m) increased when the participant used the aqua-noodles. Second, there was a statistically significant decrease in stride length when the aqua-noodles were used. Conclusion: This study helps to verify that the effect of underwater walking exercise can provide a suitable walking exercise environment. The results of this study provide systematic scientific information about how walking in water can be used for the rehabilitation of patients and the elderly.

• 대한정형외과스포츠의학회:학술대회논문집
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• 2004.09a
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• pp.1-1
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• 2004

• Physical Therapy Rehabilitation Science
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• v.6 no.3
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• pp.120-126
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• 2017

Objective: The purpose of this study was to investigate the effects of backward treadmill gait training between underwater and ground environments on strength, proprioception, and walking ability in persons with stroke. Design: Randomized control trial. Methods: Twenty eight subjects participated in the study in which they were randomly assigned to either the underwater backward treadmill training (UBTT) group (n=13) or the BTT group (n=15). In both groups, forward gait training was performed for 20 minutes on the ground treadmill. The UBTT group performed backward gait on an underwater treadmill for 20 minutes while the BTT group performed backward gait on a ground treadmill for 20 minutes. The gait training in each group was performed twice a week for a total of six weeks. Muscle strength, proprioception, and gait ability was assessed using a digital power meter, joint angle recurrence method using the smartphone protractor application, the Figure-of-Eight walk test (F8W) and the functional gait assessment (FGA) respectively. Results: Both groups showed significant improvement in strength, F8W and FGA scores after training (p<0.05). However, there was no statistically significant difference between the two groups. Both groups showed significant improvement in proprioception after training (p<0.05). In the comparison between the two groups, there was a greater significant change in the UBTT group for joint proprioception (p<0.05). Conclusions: In this study, it was found that both backward treadmill gait training programs were effective on strength, proprioception, and gait ability, and that underwater training was particularly effective on proprioception compared to ground training.