• 한국정밀공학회지
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• 제32권10호
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• pp.885-890
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• 2015

Walking on split-belt treadmill has been applied to study walking disabilities, such as osteoarthritis (OA), to show asymmetric walking characteristics. In this study, we compared asymmetric walking in OA patients with healthy subjects under split-belt conditions and examined the reproduction of walking asymmetry in OA. Seven OA patients were instructed to walk at four frequencies, while four healthy subjects walked on a treadmill with tied-belt and split-belt conditions. To compare walking asymmetries, kinetic and kinematic measurements were made using force-plates and motion capture cameras, and subsequently center of mass (CoM) velocity, mechanical work and potential energy were calculated. Horizontal velocity change during split-belt walking of healthy subjects was similar to OA patients. Difference of mechanical work during single support phase occurred due to fall of CoM in fast belt. OA walking asymmetry could be reproduced by reducing differences of belt speeds to prevent rapid fall of CoM.

• 대한물리의학회지
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• 제7권4호
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• pp.459-469
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• 2012

PURPOSE: The purpose of the present study was to examine changes caused by asymmetric bag carrying methods to carry the bag with one shoulder only to plantar pressure during walking. METHODS: Twenty three normal adults without any gait problem participated in the present study. Experimental conditions used consisted of walking without carrying any bag(condition 1), walking wearing a bag on both shouders (condition 2), and walking wearing a bag on the right shoulder(condition 3) and the weight of the bag was set to 15% of each subject's body weight. All the subjects were instructed to participate in all experiments under these three conditions and plantar pressures were measured from the subjects' right and left feet using an F-scan system while the subjects were walking under the three conditions. To analyze the measured plantar pressure, the sole was divided into seven areas (Hallux, Toe, Met1, Met23, Met45, Mid foot and Heel) and maximum plantar pressures in individual areas were measured. RESULTS: The results of measurement of plantar pressures under three walking conditions did not show significant changes in any areas of the left and right feet except for the mid foot area of the right food. The asymmetry between the left and right feet was examined and the results showed significant differences only in area Met23 under condition 2 and did not show significant differences in any other areas. CONCLUSION: On comprehensively considering the results of the present study, it could be seen that asymmetric bag carrying did not have large effects on changes in plantar pressure during walking compared to symmetric carrying. The reason for this is considered to be posture adjusting mechanisms against load positions.

• 한국운동역학회지
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• 제21권3호
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• pp.309-315
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• 2011

The purpose of this study was to evaluate the effect of asymmetric muscle force in lower extremity on dynamic balance during walking. Sixteen elementary students(age: 12.3${\pm}$0.7 yrs, height: 149.4${\pm}$9.7 cm, weight 40.6${\pm}$7.8 kg) who have no musculoskeletal disorder were recruited as the subjects. Temporal parameters, M-L inclination angle of XCoM-CoP, M-L and A-P CoP, loading rate, and decay rate were determined for each trial. For each dependent variable, a independent-sample t-test was performed to test if significant difference existed between each conditions(p<.05). The displacement of antero-posterior COP during RTO-LHC1 in SG was siginificantly smaller than corresponding value in AG. In contrast, the displacement of medio-lateral COP during RTO-LHC1 in SG was greater than those of AG. It seems that imbalance of muscle force may result in increasing the medio-lateral stance in order to minimize the instability. We found that the asymmetric muscle force in the lower extremity may be a reason for the awkward control of impact force.

• 전기학회논문지
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• 제63권4호
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• pp.541-545
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• 2014

In this paper, the angle of the thighs that appear during walking condition to balance estimation to the left and right leg was occurred during normal walking. Get over to the limitations of gait analysis using image processing or foot pressure that was used a lot in the previous, the angle of the thigh were used for estimation of asymmetric gait. We implemented heathy five adult male to test targeting and gait and obtained cycle data from 10 times. For this research, Thigh-Angle measurement device were developed, and attached to in a position of $20^{\circ}$ for flexion and $15^{\circ}$ for extension to measure the angle of the thigh. Also, in order to verify the reliability of estimation of asymmetric gait using thigh-angle, it was compared with the result of asymmetric gait estimation using foot pressure. The results of this paper, using the thigh angle is the average of 16.84% higher than using pressure to accuracy of determine the gait imbalance.

• The Journal of Korean Physical Therapy
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• 제27권4호
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• pp.228-233
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• 2015

Purpose: Gait is the most basic element when evaluating the quality of life with activities of daily living under ordinary life circumstances. Symmetrical use of the lower extremities requires complicated coordination of all limbs. Thus, this study examined asymmetry of muscle activity quadriceps femoris and tibialis anterior as a baseline for training during over-ground walking and stair walking of stroke patients. Methods: Subjects were 14 stroke patients included as one experimental group. Gait speed used in this study was determined by the subject. Low extremity paretic and non-paretic EMG was compared using the surface EMG system. Results: The low extremity EMG difference was statistically significant during over-ground walking and stair walking (p<0.05). The result of low extremity EMG substituted symmetry ratio formula was compared to EMG symmetry ratio in both legs during over-ground walking and stair walking. The average symmetry ratio of quadriceps femoris during over-ground walking was 0.65, and average symmetry ratio of quadriceps femoris during stair walking was 0.47, with significant difference (p<0.05). Conclusion: EMG data was higher in stair walking than over-ground walking. However, in the comparison of symmetry ratio, asymmetric EMG of quadriceps femoris was significantly increased during stair walking. These findings suggested that application of stair walking for strengthening of both legs can be positive, but the key factor is maintaining asymmetrical posture of both legs. Therefore, physical therapists should make an effort to reduce asymmetry of quadriceps femoris power during stair walking by stroke patients.

• 대한통합의학회지
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• 제10권4호
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• pp.145-151
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• 2022

Purpose : Stroke patients exhibit abnormal walking patterns such as slow walking speed and asymmetrical walking values. The recovery of symmetrical walking in the stance phase using a treadmill means improvements in walking speed and asymmetrical walking. The purpose of this research was to investigate the effect of unilateral step treadmill training (USTT) on gait speed and the recovery of symmetrical walking in chronic stroke patients. Methods : Fifteen patients (11 men and 4 women) with chronic stroke participated in this study. The 10-meter walk test (10MWT) and GAITRite system were used to determine the intervention-related changes in gait speed and symmetrical walking values such as non-paretic step length (NSL), non-paretic step time (NST), paretic single-support time (PSST), step length asymmetry (SLA), and step time asymmetry (STA) after USTT. All participants completed USTT and underwent measurements at 3 different times: at pretest, posttest, and the follow-up test. Repeated-measures analysis of variance was used to compare walking speed and asymmetrical walking values. The statistical significance level was set at p<.05. Results : Walking speed by 10MWT (p<.05) showed significant improvements after USTT as follows: at pretest and posttest (p<.05), posttest and follow-up test (p<.05), and pretest and follow-up test (p<.05). Recovery of symmetrical walking patterns such as NSL (p<.05), NST (p<.05), and SLA (p<.05) were observed after USTT. However, no significant improvements were found in PSST (p>.05) and STA (p>.05) in symmetrical gait. Conclusion : This study suggests that USTT may have a positive effect on walking speed and symmetrical walking patterns in chronic stroke patients. Thus, this study contributes to the existing knowledge about the usefulness of USTT for the effective management of patients with chronic stroke. Further studies are needed to generalize these findings.

• 한국운동역학회지
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• 제18권1호
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• pp.169-178
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• 2008

본 연구는 계단 보행 중 연속적인 두 스텝의 3차원적 지면반력 파라미터를 제공하고, 계단의 너비에 따른 지면 반력 파라미터의 차이 및 비대칭성과 일관성을 규명하는데 있다. 10명의 성인 대상자가 본 실험에 참여하였으며, 각 10번의 평지, 상향 및 하향보행을 3가지의 다른 너비의 계단에서 실시하였다. 본 연구를 수행한 결과 다음과 같은 결론을 얻었다. 첫째, 계단의 너비는 대부분의 지면반력 파라미터들의 패턴이나 일관성, 비대칭지수에 영향을 미치지 않았다. 둘째, 평지 보행과 계단보행은 지면반력 파라미터의 패턴에서 큰 차이를 보였다. 평지보행과 상향보행은 Fz1, Fz2, 그리고 Fz3로 구성되는 "M" 형태를 보인 반면에 하향보행에서는 Fz2가 거의 없고 큰 Fz1과 작은 Fz3로 구성된 패턴을 보였다. 또한 계단 보행은 평지보행과 매우 다른 전 후 지면반력 패턴을 보였다. 즉 상향보행은 Fy1이 존재하지 않는 패턴을, 하향보행은 Fy2가 존재하나 매우 작은 크기를 보였다. 셋째, 계단보행의 수직 지면반력 파라미터들은 적용가능한 일관성 지수 및 비대칭 지수를 나타내었다.

• 국제물리치료학회지
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• 제9권4호
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• pp.1576-1585
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• 2018

Regularly participating in physical activity is known to improve quality of life and body composition in elderly with stroke. However, comparatively less physical activity is performed by the stroke survivors. The factors related to inactivity in elderly female stroke survivors have not been elucidated. Therefore, this study aims to compare the quality of life factors and limb compositions between the active and inactive elderly female stroke survivors. Forty nine subjects between the ages of 65 to 75 years were selected from the KNHANES data between the years 2009 to 2011. In addition, 186 agematched healthy peers were also selected for limb composition comparisons. The subjects were groups based on walking days per week: walkers; 3 days or more, non-walkers; less than 3 days per week. BMI and waist circumference were within the obesity ranges for both the non-walkers and walkers. As results, the trend for greater fat (${\pm}10%$) and lean mass (${\pm}30%$) differences were observed for non-walker and walkers, respectively. Significantly greater reasons for function limitation by stroke and hypertension were reported with significantly greater self-care difficulty was shown by the walkers. In conclusion, elderly female stroke survivals may require customized motivation and continuous support to participate in physical activity regularly.

• 문화기술의 융합
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• 제4권4호
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• pp.439-448
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• 2018

본 연구에서는 가방의 휴대 방법이 보행 시 족저압에 어떠한 변화를 일으키는지 알아보기 위하여 정상 성인 남녀 33명을 대상으로 가방을 휴대하지 않고 보행, 가방을 양쪽어깨에 메고 보행, 가방을 하나의 한쪽어깨에 메고 보행, 가방을 한쪽 손으로 들고 보행하기 등 4가지 조건에서 F-scan system을 이용해 족저압을 측정하였다. 실험을 통해 얻어진 족저압의 변화와 좌 우측 발에서의 비대칭성을 분석하였다. 네 가지 가방 휴대방식 간에 부위별 족저압을 비교해 본 결과 좌측 발은 족지와 중족을 제외하고 다섯 가지 조건 간에 유의한 차이를 보였고, 우측 발은 제4,5번 중족골두를 제외하고 모두 유의한 차이가 나타났다(P>.05). 이를 종합해 볼 때 가방을 등 뒤로 양쪽 어깨에 메는 방법을 제외하고는 어떤 방법이 발에 최소한의 부담을 주는 최선의 방법인지는 본 실험의 족저압 변화 양상을 통해서 판단하기에는 다소 부족한 면이 있다고 사료된다. 앞으로의 연구에서는 가방 휴대 방법에 따른 족저압의 변화에 대한 연구 및 비대칭성 부하가 측만증이나 후만증과 같은 비정상적 자세를 치료하는데 효과적으로 사용할 수 있는 방법에 대해서도 연구가 진행되어야 할 것이다.

• 한국컴퓨터그래픽스학회논문지
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• 제24권3호
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• pp.1-10
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• 2018

본 연구는 비대칭 가상현실 환경에 존재하는 HMD 사용자와 Non-HMD 사용자 모두에게 향상된 현존감을 제공하기 위하여 사용자의 체험 환경에 최적화된 몰입형 상호작용을 제안한다. 제안하는 몰입형 상호작용의 핵심은 HMD 사용자와 Non-HMD 사용자 사이의 비대칭 환경의 차이를 구분하여 사용자에게 최적화된 상호작용을 제시하는 것이다. 그리고 사용자 각각에게 주어지는 비대칭 가상현실 환경에서 향상된 몰입을 제공하여 현존감을 높이기 위하여 HMD 사용자에게는 공간의 몰입을 향상시키는 걷기 상호작용을, Non-HMD 사용자에게는 직접적인 조작을 통해 상황을 전체적으로 이해하고 관리함으로써 몰입을 향상시키는 손 기반 인터페이스를 설계한다. 마지막으로 몰입형 상호작용을 통해 모든 사용자가 향상된 현존감을 제공받으면서 동시에 각각의 체험에 환경에 특화된 경험을 하였음을 설문실험을 통해 검증한다. 이러한 과정들을 통하여 제안한 상호작용이 비대칭 가상현실에서 Non-HMD 사용자도 보조자가 아닌 참가자로써 HMD 사용자와 함께 몰입할 수 있음을 확인한다.