정지신호과제의 수행이 동작의 실행과 정지기능에 미치는 영향

권중원,남석현,김중선,Kwon, Jung-Won,Nam, Seok-Hyun,Kim, Chung-Sun 대한물리치료학회 2011 대한물리치료학회지 Vol.23 No.1

Purpose: We studied the changes in motor response time and stop signal response time following visuomotor skill learning of a stop signal task in young healthy subjects. This study also was designed to determine what an effective practice is for different stop signals in the stop signal task (SST). Methods: Forty-five right-handed normal volunteers without a history of neurological dysfunction were recruited. They all gave written informed consent. In all subjects, motor reaction time (RT) and stop signal reaction time (SSRT) were measured for the stop signal task. Tasks were classified into three categories: predictable-stop signal task (P-SST) practice group random-stop signal task (R-SST) practice group control group. Results: Motor reaction time in the P-SST was significantly reduced when comparing pre- and post-tests (p<0.05). Stop signal reaction times in the P-SST and the R-SST were significantly reduced following motor skill learning (p<0.05). Also, the reaction time of the R-SST was shorter than that of the P-SST. Conclusion: These findings indicate that practice of an SST improves motor performance and stop function for some stop signals in the SST. P-SST practice was effective in the stop function of regular movement because of faster of the motor prediction and preparation but the R-SST was effective in the stop function of movements because of faster motor selection.

The Effect of Different Head Positions in Sitting on Head/Shoulder Posture and Muscle Activity

권중원,남석현,최용원,김중선,Kwon, Jung-Won,Nam, Seok-Hyun,Choi, Yong-Won,Kim, Chung-Sun The Korean Society of Physical Therapy 2013 대한물리치료학회지 Vol.25 No.4

Purpose: This study was to investigate whether the two different head postures, natural and ideal head posture, affect head/shoulder posture and muscle activity. Methods: Thirty healthy subjects with the forward head and round shoulder posture were participated in this study. This study utilized a within-subjects design with subjects being positioned into two sitting positions: natural head posture (NHP) and ideal head posture (IHP). Forward head angle (FHA) and forward shoulder angle (FSA) of each subject were measured for assessing the head/shoulder posture and muscle activities of upper trapezius (UT), lower trapezius (LT), and serratus anterior (SA) during the forward overhead reaching. Results: There were significant increases in both FHA and FSA after taking IHP, which showed greater angles than in taking NHP. In change of muscle activities, there were significant decreases in both LT and SA after taking IHP, which showed lower activities than in taking a NHP, whereas there was no significant change in UT. Conclusion: These findings demonstrate that postural alterations associated with forward head and rounded shoulder postures could alter scapular kinetics and muscle activity during the forward overhead reaching.

정상 성인에서 경두개 직류 전류자극과 기능적 전기자극에 의한 대뇌피질의 활성화: 사례연구

권용현,권중원,박상영,장성호,Kwon, Yong-Hyun,Kwon, Jung-Won,Park, Sang-Young,Jang, Sung-Ho 대한물리치료학회 2011 대한물리치료학회지 Vol.23 No.1

Purpose: Recently, many studies have demonstrated that application of external stimulation can modulate cortical excitability of the human brain. We attempted to observe cortical excitability using functional magnetic resonance imaging (fMRI) during the application of transcranial direct current stimulation (tDCS) or functional electrical stimulation (FES). Methods: We recruited two healthy subjects without a history of neurological or psychiatric problems. fMRI scanning was done during? each constant anodal tDCS and FES session, and each session was repeated three times. The tDCS session consisted of three successive phases (resting phase: 60sec dummy cycle: 10sec tDCS phase: 60sec). The FES session involved stimulation of wrist extensor muscles over two successive phase (resting phase: 15sec FES phase: 15sec). Results: The average map of the tDCS and FES analyses showed that the primary sensory-motor cortex area was activated in all subjects. Conclusion: Our findings show that cortical activation can be induced by constant anodal tDCS and FES. They suggest that the above stimuli have the potential for facilitating brain plasticity and modulating neural excitability if applied as specific therapeutic interventions for brain injured patients.

정지신호과제의 수행에 따른 보행정지 시 다리 근전도 및 지면반발력 비교

구동균,권중원,Koo, Dong-Kyun,Kwon, Jung-Won 대한고유수용성신경근촉진법학회 2022 PNF and Movement Vol.20 No.1

Purpose: The purpose of this study was to investigate the association between cognitive and motor inhibition by comparing muscle activity and ground reaction force during unplanned gait termination according to reaction time measured through the stop-signal task. Methods: Sixteen young adults performed a stop-signal task and an unplanned gait termination separately. The subjects were divided into fast and slow groups based on their stop-signal reaction time (SSRT), as measured by the stop-signal task. Electromyography (EMG) and ground reaction force (GRF) were compared between the groups during unplanned gait termination. The data for gait termination were divided into three phases (Phase 1 to 3). The Mann-Whitney U test was used to compare spatiotemporal gait parameters and EMG and GRF data between groups. Results: The slow group had significantly higher activity of the tibialis anterior in Phase 2 and Phase 3 than the fast group (p <0.05). In Phase 1, the fast group had significantly shorter time to peak amplitude (TPA) of the soleus than the slow group (p <0.05). In Phase 2, the TPA of the tibialis anterior was significantly lower in the fast group than the slow group (p <0.05). In Phase 3, there was no significant difference in the GRF between the two groups (p >0.05). There were no significant difference between the two groups in the spatiotemporal gait parameters (p >0.05). Conclusion: Compared to the slow group, the fast group with cognitive inhibition suppressed muscle activity for unplanned gait termination. The association between SSRT and unplanned gait termination shows that a participant's ability to suppress an incipient finger response is relevant to their ability to construct a corrective gait pattern in a choice-demanding environment.

만성 뇌졸중 환자에서 장기간 지팡이 사용이 건측 하지 통증 발현에 미치는 영향

손성민,권중원,남석현,김중선,Son, Sung-Min,Kwon, Jung-Won,Nam, Seok-Hyun,Kim, Chung-Sun 대한물리치료학회 2013 대한물리치료학회지 Vol.25 No.1

Purpose: To investigate whether the long-term use of a cane induces pain in the unaffected lower limb of stroke patients. Methods: A total of 107 stroke patients with chronic hemiparesis were recruited in this study and classified into two groups; a cane-use group (n=49) and non-cane-use group (n=58). The existence of pain in the unaffected lower limb was assessed on a visual analog scale in the hip, knee, and ankle joint, and the University of Alabama pain behaviors scale (UAB pain behavior scale) used to measure the intensity of pain. In addition, the Motricity Index (MI) was tested in the upper and lower extremities. Results: The proportion of pain in each joint of the lower limb was significantly higher in the cane-use group, compared to the non-cane-use group (p<0.05). In addition, significant differences were observed on the UAB pain behavior scale between the two groups. The lower MI score was significantly lower in the cane-use group, compared with the control group. However, no difference was observed in MI scores of the upper limb between the two groups. Conclusion: These findings reveal that long-term cane usage can induce pain in the unaffected lower limb of stroke patients. We suggest careful consideration when prescribing a cane, depending on functional ability in hemiparetic patients, and recommend continuous evaluation for pain in the affected lower limb.

발목관절의 각도가 무릎관절 폄근의 근활성도에 미치는 영향

여상석 ( Sang Seok Yeo ),권중원 ( Jung Won Kwon ),김중선 ( Chung Sun Kim ) 대한물리의학회 2009 대한물리의학회지 Vol.4 No.1

Purpose The purpose of this study was to find the effect of ankle joint angle on knee extensor electromyographic activity following knee extension exercise. Methods Ten male university students participated in the study. The subjects performed isometric maximal voluntary knee extensor contractions (MVC) and knee extensor EMG activity measured in with three different ankle joint angle, The EMG activity of rectus femoris (RF), vastus medialis (VM), vastus lateralis (VL) were measured using surface electromyography. Results EMG activity of vastus lateralis following the change of ankle joint angle was shown statistically significant difference, Conclusion Ankle plantar flexion position insrease EMG activity of vastus lateralis during knee extension exercise.

뇌졸중 환자의 트레드밀 훈련 시 손잡이 유무 및 위치가 보행 및 균형에 미치는 영향

남석현 ( Seok-hyun Nam ),강경우 ( Kyung-woo Kang ),권중원 ( Jung-won Kwon ),최용원 ( Yong-won Choi ),김중선 ( Chung-sun Kim ) 대한물리치료학회 2013 대한물리치료학회지 Vol.25 No.1

Purpose: The purpose of this study was to examine the influence of a handrail (presence and position) on treadmill gait and balance in stroke patients during gait training. Methods: 39 patients with stroke (male 31, female 8) participated in this study. The training groups were classified into a no-handrail group (NHG), front handrail group (FHG), and bilateral handrail group (BHG). Each group comprised 13 subjects. The subjects were trained to walk in a straight path 30 minutes per day for 8 weeks. The Good Balance System was used to measure static balance and dynamic balance. To measure walking ability, timed up and go (TUG) was also assessed. Results: The NHG showed no significant differences in static balance, dynamic balance, and TUG. The FHG was significantly different in their medial-lateral speed of static balance, dynamic balance, and TUG. The BHG was significantly different in their static balance, dynamic balance, and TUG. Conclusion: These findings consider the effects of holding handrails concomitantly with changes in postural stability. We conclude that for training stroke patients, treadmill walking while holding handrails improves balance and gait more than treadmill walking without holding handrails. The resulting changes in muscle activity patterns may facilitate the transfer to a gait pattern. The results of this study suggest methods for training treadmill walking in stroke patients.

완충 용액의 유산 농도와 pH가 법랑질의 재광화에 미치는 영향

권중원,서덕규,송윤정,이윤,이찬영 大韓齒科保存學會 2008 Restorative Dentistry & Endodontics Vol.33 No.6

There are considerable in vitro and in vivo evidences for remineralization and demineralization occurring Simul-taneously in incipient enamel caries. In order to "heal" the incipient dental caries, many experiments have been carried out to determine the optimal conditions for remineralization. It was shown that remineralization is affected by different pH, lactic acid concentrations, chemical composition of the enamel, fluoride concentrations, etc. Eighty specimens from sound permanent teeth without demineralization or cracks, 0.15 mm in thickness, were immersed in lactic acid buffered demineralization solutions for 3 days. Dental caries with a surface zone and subsurface lesion were artificially produced. Groups of 10 specimens were immersed for 10 or 12 days in lactic acid buffered remineralization solutions consisting of pH 4.3 or pH 6.0, and 100, 50, 25, or 10 mM lactic acid. After demineralization and remineralization, images were taken by polarizing microscopy (×100) and micro-computed tomography. The results were obtained by observing images of the specimens and the density of the caries lesions was determined. 1.As the lactic acid concentration of the remineralization solutions with pH 4.3 was higher, the surface zone of the carious enamel increased and an isotropic zone of the subsurface lesion was found. However, the total decalcification depth increased at the same time 2.In the remineralization solutions with pH 6.0, only the surface zone increased slightly but there was no significant change in the total decalcification depth and subsurface zone. In the lactic acid buffer solutions with the lower pH and higher lactic acid concentration, there were dynamic changes at the deep area of the dental carious lesion. 본 연구의 목적은 유산 완충 용액의 pH및 유산 농도 변화가 법랑질에서 인공 우식 병소의 재광화 양상에 미치는 영향을 평가하기 위함이다. 유산 완충 용액을 이용하여 법랑질을 탈회시키고, 유산의 농도가 100, 50, 25, 10 mM이고 pH가 4.3인 네 가지 재광화 용액 (Group 1, 2, 3, 4)에 10일, pH 6.0인 네 가지 재광화 용액 (Group 5, 6, 7, 8)에 12일간 처리한 후 무기질의 양적 변화를 편광 현미경에서 얻은 상에서의 탈회 깊이의 변화, 우식 표면층 깊이의 변화로 측정하였다. 또한 micro-computed tomography (micro-CT)를 이용하여 탈회 후와 재광화 후를 촬영하여 얻은 상으로부터 lesion부위의 density를 비교하였다. 1. pH 4.3에서 유산 농도가 증가할수록 우식 표면층의 증가와 표층하 탈회부 중 심층부의 isotropic zone등의 재광화 현상을 보이나, 전체 탈회 깊이 역시 증가하였다. 2. pH 6.0에서 우식 표면층에 국한된 재광화 현상을 보이고, 전체 탈회 깊이는 변화가 없었다. 이상의 실험 결과로 미루어 포화도가 일정한 유산 완충 용액으로 재광화 유도시 pH가 낮고 유산의 농도가 높을수록 표면으로부터 심층부 동역학적 변화에 더 영향을 주었으며, micro-CT를 이용한 우식 병소부위의 density 확인을 통해 무기질의 침착과 방출 현상을 객관적으로 평가할 수 있었다.

뇌졸중 환자의 apraxia test of Ambrosoni의 신뢰도 연구

김중선,권중원,남석현 대구대학교 특수교육재활과학연구소 2011 특수교육재활과학연구 Vol.50 No.4

실행증은 뇌손상으로 인하여 운동 통합의 장애가 발생하며, 이로 인하여 감각이나 운동신경의 손상이 없음에도 불구하고 숙련된 행동을 하지 못하는 행위를 말한다. 실행증을 동반한 뇌졸중 환자의 경우 일반 뇌졸중 환자와 비교시 특징적인 징후를 보이며, 치료법 또한 다르게 실시 되고 있다. 따라서 실행증을 동반한 환자를 정확히 판별하기 위해서는 정확한 평가도구가 필요하다. 하지만 지금까지의 실행증 평가 도구는 상지만을 측정하여, 하지의 기능을 정확히 구별하지 못하는 단점이 있다. 따라서 본 연구는 뇌졸중 환자 30명을 대상으로 상지와 하지 모두 실행증 유무를 평가할 수 있는 Ambrosoni 등에 의해 개발된 실행증 평가 도구의 신뢰도를 검증하고자 하였다. 연구 결과 Ambrosoni 등에 의해 개발된 실행증 평가 도구의 측정자 내 신뢰도(0.96)는 높게 나타났으며, 측정자간 신뢰도(0.72)는 보통 이상의 신뢰도가 나타났다. 이는 임상에서 실행증 평가 도구로서의 충분한 활용가치가 있음을 증명 하였다. 기존의 실행증을 평가하기위한 평가 도구들은 대부분 상지의 기능만을 이용하여 실행증 유 무를 판단하여야 하는 한계가 있다. 따라서 본 연구에서 실시한 상지 실행증과 하지 실행증의 모두 평가가 가능한 Ambrosoni 등에 의해 개발된 실행증 평가 도구의 신뢰도 검사를 통하여, 임상적 활용가치가 높은 평가 도구이며, 이에 따른 적극적인 활용이 필요할 것으로 생각된다. 또한 앞으로의 연구에서는 환자의 특성에 따른 다양한 연구가 이루어져야 할 것이다.