• 재활복지공학회논문지
• /
• 제7권2호
• /
• pp.19-26
• /
• 2013

본 논문에서는 다수의 특징 값 중에서 적합한 특징 및 채널을 선택하는 sEMG 신호기반 보행단계 인식기법을 제안한다. 제안하는 방법은 sEMG 신호 기반 분류기를 이용하여 하지 절단 환자의 동력의족을 제어하며, 적응적으로 특징 및 채널들을 선택하여 임베디드 시스템의 신호처리과정에서 발생하는 오버헤드를 감소시킨다. 또한 피험자의 보행 습관에 따라 근육 발달도가 다르다는 특성을 이용하여 피험자의 보행단계에 따라 사용 빈도가 높은 근육과 특징 추출 알고리즘을 선택함으로서 정확도를 향상시킨다. 실험 결과 피험자마다 인식율이 높은 근육이 다르다는 것을 발견하였다. 또한 모든 특징들과 채널들을 이용하는 기존 방법의 경우 50%의 평균정확도를 보인 반면에 제안한 방법은 91%의 평균정확도를 보였다. 따라서 소수의 발달된 근육과 이에 맞는 특징을 사용한 sEMG기반 보행단계인식 방법이 하지절단환자의 동력의족을 제어하는 데 적용될 수 있음을 확인하였다.

• PNF and Movement
• /
• 제15권2호
• /
• pp.185-194
• /
• 2017

Purpose: The purpose of this study was to prove the effects of the PNF patterns combined with whole-body vibration (PWBV) training on muscle strength, balance, walking speed, and endurance in stroke patients. Methods: Sixteen subjects were randomly assigned to the PWBV group (n=8) and the whole-body vibration (WBV) group (n=8). The PWBV group performed PNF pattern exercises using sprinter combined with WBV, while the WBV group performed using squatting for 30 minutes. Both groups performed therapeutic interventions five days per week over a period of four weeks. The manual muscle test, timed up and go test (TUG), 10-meter walk test (10MWT), and six-minute walk test (6MWT) were used to assess the muscle strength, balance, and gait of the participants. The SPSS Ver. 19.0 statistical program was used for data processing. Statistical analysis included a pared t-test to compare the pre- and post-intervention, and an independent t-test was used to compare groups. The significance level was set as 0.05. Results: The PWBV group and WBV group showed significant improvements in the TUG, 10MWT, and 6MWT (P<0.05). Significant differences between the PWBV and WBV groups were found (P<0.05). Conclusion: The PWBV improved muscle strength, balance, gait speed, and endurance in stroke patients. Thus, PWBV may be suggested as a therapeutic intervention in patients with stroke hemiplegia.

• 한국운동역학회지
• /
• 제16권2호
• /
• pp.145-151
• /
• 2006

A large interindividual variability and some abnormally kinematic patterns at the lower extremity were the main features of the gait in children with Down syndrome. The purposes of this study were to investigate the gait asymmetry and biomechanical difference between dominant leg and non dominant leg in children with Down syndrome. Seven boys with Down Syndrome(age: $120{\pm}0.9yrs$, weight $34.4{\pm}8.4kg$, leg length: $68.7{\pm}5.0cm$) participated in this study. A 10.0 m ${\times}$ 1.3 m walkway with a firm dark surface was built and used for data collection. Three-dimensional motion analyses were performed to obtain the joint angles and range of motions. The vertical ground reaction forces(%BW) and impulses($%BW{\cdot}s$) were measured by two force plates embedded in the walkway. Asymmetry indices between the legs were computed for all variables. After decision the dominant leg and the non dominant leg with max hip abduction angle, paired samples t-test was employed for selected kinematic and ground reaction force variables to analyze the differences between the dominant leg and the non dominant leg. The max hip abduction angle during the swing phase showed most asymmetry, while the knee flexion angle at initial contact showed most symmetry in walking and running. The dominant leg showed more excessive abduction of hip in the swing phase and more flat-footed contact than the non dominant leg. Vertical peak force in running showed more larger than those of in walking, however, vertical impulse showed more small than walking due to decrease of support time. In conclusion, the foot of dominant leg contact more carefully than those of non dominant leg. And also, there are no significant difference between the dominant leg and the non dominant leg in kinematic variables and ground reaction force due to large interindividual variability.

• 한국운동역학회지
• /
• 제17권3호
• /
• pp.147-154
• /
• 2007

This study's purpose is to investigate the effects on leg muscle activity caused by perturbation, using a trapdoor system during the support phase of gait for healthy adults (n = 6, height $177.5{\pm}5.5cm$, weight $81.0{\pm}9.5kg$, age $30.0{\pm}3.3yrs$). The trapdoor had the functional ability of causing inversion or eversion. The release time for the trapdoor was specified for two times, 0.3 and 0.5 seconds after heel contact. While altering these variables, EMG was recorded for the leg muscles (rectus femoris, biceps femoris, vastus lateralis, tibialis anterior, gastrocnemius, soleus). The following conclusions were derived. The steptime was longer for the 0.5s eversion than 0.3s inversion condition. So in order to regain stability after the perturbation the unsupporting leg reached forward rapidly. This quick reflex can be observed through the center of pressure (COP) and its rapid change in direction. The gastrocnemius was activated throughout the total experiment. There was a low amount of activity recorded in the rectus femoris, vastus lateralis and tibialis anterior except for the condition of inversion 0.3s. For most of the conditions, the highest average EMG peak values were recorded during the condition of inversion 0.3s. The iEMG patterns were similar for the conditions of inversion 0.3s and eversion 0.3s. To cope with the rapid change in these conditions, the biceps femoris was activated. During the experiment except for the condition of normal gait, the activity of the soleus and gastrocnemius was relatively high. Therefore, to prevent injury from perturbation of the lower leg strengthening of the soleus and gastrocnemius is required. Likewise to prevent injury to the thigh strengthening for the biceps femoris.

• Physical Therapy Rehabilitation Science
• /
• 제3권1호
• /
• pp.13-19
• /
• 2014

Objective: The purpose of this study was to determine the effects of Augmented Reality-based Postural Control (ARPC) training on balance and gait function in patients with stroke. Design: Single-blind randomized controlled trial. Methods: Twenty participants who experienced a stroke were enrolled in the study and randomly assigned to the ARPC (n=10) or control group (n=10). Subjects in both groups received conventional physical therapy for 60 min per session, 5 days per week, for 4 weeks. In addition, subjects in the ARPC group received ARPC training for 30 min per day, 3 days per week, for 4 weeks. The participants watched established normal postural control patterns on a head-mounted display and repeated the movements in ARPC training. Outcome measurements were assessed using the Berg Balance Scale (BBS) and 10-Meter Walk Test (10MWT) before and after 4 weeks of training. Results: Of the 20 randomized participants, only 18 completed the 4-week training program. The ARPC group showed significant improvement in the BBS and 10MWT after training (p<0.05). Meanwhile, the control group did not exhibit improvement in either variable. In addition, the ARPC group showed significantly greater improvement than the control group in the 10MWT (p<0.05), whereas no significant difference was observed between the groups for the BBS. Conclusions: The results of this study confirmed the benefits of ARPC training on dynamic balance and functional gait ability. Additionally, this study may provide evidence supporting the use of an ARPC training program for improving balance and gait ability in patients after a chronic stroke.

• 한국콘텐츠학회논문지
• /
• 제12권1호
• /
• pp.318-328
• /
• 2012

본 연구는 PNF 결합패턴이 뇌졸중 환자의 마비측 하지 근 활성도와 보행 능력에 어떠한 영향을 미치는 지를 알아보고자 실시하였다. 뇌졸중 환자 20명을 대상으로 하여 PNF 결합패턴(주 4회, 6주간)을 적용하는 실험군(n=10)과 일반 운동치료만을 적용하는 대조군(n=10)으로 무작위 배정하였다. 하지 근 활성도 측정은 활동전위의 실효치 값으로 분석하였고, 보행능력검사는 10MWT, DGI, F8WT를 이용하여 측정하였다. 운동 적용 방법에 따른 측정 시점에 대한 대조군과 실험군의 유의성 검정은 Two-way repeated measure ANOVA를 실시하였다. 그 결과, 근 활성도를 알아보기 위해 측정한 RF(p<.05), VM, TA, LH, LG(p<.001) 근육 모두 각 측정 시기에서 통계적으로 유의한 증가가 있었으며, VM, TA, LH, LG(p<.001)에서 측정시간과 군 간의 상호작용이 나타났다. 보행능력을 알아보기 위해 실시한 10MWT, DGI, F8WT 검사에서도 각 측정 시기에서 통계적으로 유의한 향상이 있었으며(p<.001), 10MWT(p<.05), DGI(p<.001), F8WT(p<.01)에서 측정시간과 군 간의 상호작용이 나타났다. 본 연구의 결과로 보아 PNF 결합패턴은 뇌졸중 환자의 마비측 근 활성도를 증가시키는데 도움을 주고, 보행 능력 개선에 유용한 전략으로 사용될 수 있음을 증명하였다.

• 한국운동역학회지
• /
• 제14권3호
• /
• pp.177-189
• /
• 2004

Kinematic and kinetic analysis using 3D Motion Capture system are common, yet there is little in the literature that discuss the relationship and coactivity between muscles during the golf swing. The purpose of this study was to describe the relationship between the employed 16 muscles during golf swing. We could observe 3 muscle patterns such as 'Line' shape, 'L' shape, and 'Loop' shape for the golf swing activity. The 'Line' shape indicates that two muscles act almost perfectly in phase, and the 'L' shape represents that two muscles act in a reciprocating manner(When one is active, the other is quiescent and vice versa). And the 'Loop' shape indicates that two muscles act sequently(After one is active, the other act). In these results, we knew the muscle patterns during golf swing is similar to the patterns during gait. And we presented it was possible to show the consistence of golf swing through the frequency analysis of muscle patterns. We believe that the results potentially useful for the golf players and coaches to analyze their performance.

• 한국소음진동공학회논문집
• /
• 제24권4호
• /
• pp.299-309
• /
• 2014

When biped robots make turns, the ability to walk stably and precisely along any circular path is crucial. In this context, inverse kinematics solutions are found for accurate gait realization, and new zero moment point(ZMP) equations are derived with respect to the cyclindrical coordinate system to facilitate generation of stable walking patterns. Then, appropriate steady and transitional walking patterns are both proposed in form of time functons. Subsequently, walking patterns for a path but of different speeds are generated using the functions and associated formulas, and preliminarily checked for stability based on the ZMP equations. Upon comparison of those cases, one can see how and when robots may fall down during circular walking. Finally, those patterns are put to test on the sample robot by ADAMS(R) along with the inverse kinematics solutions and a new balance control scheme compensating for insufficient stability particulary during the initial transition period. Test results show that the robot can walk along the circular path as predicted at a resonably high speed despite the distributed mass and ground contact effects, validating effectiveness of the suggested approach.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2003년도 하계종합학술대회 논문집 V
• /
• pp.2891-2894
• /
• 2003

This paper describes the possibility of analyzing gait pattern from the variation of the lower leg electrical impedance. This impedance is measured by the four-electrode method. Two current electrodes are applied to the thigh and foot., and two potential electrodes are applied to the lateral aspect. medial aspect, and posterior position of lower leg. We found the optimal electrode position for knee and ankle joint movements based on high correlation coefficient, least Interference, and maximum magnitude of impedance change. From such features of the lower leg impedance, it has been made clear that different movement patterns exhibit different impedance patterns and impedance level.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2003년도 하계종합학술대회 논문집 V
• /
• pp.2887-2890
• /
• 2003

This paper describes the possibility of analyzing gait pattern from the variation of the lower leg electrical impedance. This impedance is measured by the four-electrode method. Two current electrodes are applied to the thigh, knee, and foot, and two potential electrodes are applied to the lateral, medial, and posterior position of lower leg. The correlation coefficients of the joint angle and the impedance change from human leg movement was obtained using electrogoniometer and 4ch impedance measurement system developed in this study. We found the optimal electrode position for ankle, knee and hipjoint movements based on high correlation coefficient, least interference, and maximum magnitude of impedance change. The correlation coefficients of the ankle, knee, and the hip movements -0.87, 0.957 and 0.80. respectively. From such features of the lower leg impedance, it has been made clear that different movement patterns exhibit different impedance patterns and impedance level. This system showed possibility that lower leg movement could be easily measured by impedance measurement system with a few skin-electrodes.