• The Journal of Korean Physical Therapy
• /
• 제24권2호
• /
• pp.90-97
• /
• 2012

Purpose: The purpose of this study was to assess the effects of virtual reality-based continuous slow exercise on muscle strength and dynamic balance capacity, in older adults over 65 years of age. Methods: Twenty-six volunteers were randomly divided into two groups; a Virtual Reality (VR) exercise-group ($67.8{\pm}4.1$ yrs) and a Control group ($65.5{\pm}5.2$ yrs). The VR group participated in eight weeks of virtual reality exercise, utilizing modified Tai-Chi provided by a motion capture system, and the Control group had no intervention. The hip muscle strength and dynamic balance of the members of both the VR group and the Control group were measured at pre- and post-intervention, using a multimodal dynamometer, and backward stepping test, respectively. Results: 1. After the 8-week VR-based exercise, the VR group showed significant improvement of hip strength, compared to the control group: hip extension (p=0.00), flexion (p=0.00), abduction (p=0.00), and adduction (p=0.00). 2. After the 8-week VR-based exercise, the VR group showed significant improvement of dynamic balance capacity as ground reaction force, compared to the control group. Eyes opened backward stepping test: Fx (+) (p=0.00), Fy (-) (p=0.02), Ver (+) (p=0.02) direction. Eyes closed backward stepping test: Fx (+) (p=0.04), Fy (-) (p=0.04), Ver (+) (p=0.03) direction. Conclusion: The VR group showed improvement of their hip muscle strength, and dynamic balance capacity. Therefore VR-based continuous slow exercise would contribute to reducing the risk of falls in the elderly.

• 대한기계학회논문집A
• /
• 제38권4호
• /
• pp.345-354
• /
• 2014

본 논문에서는 키넥트센서(Kinect sensor)와 확장칼만필터(Extended Kalman Filter : EKF)를 이용하여 사람과 로봇간의 상대위치 및 각도와 상대속도를 실시간으로 추정하는 알고리즘을 제안한다. 또한, 다양한 이동모드에 따른 모바일로봇의 사람과의 근접동반이동 제어를 수행한다. HOG 및 SVM을 이용한 사람 두부 및 어깨 검출 알고리즘을 통해 사람을 검출하고, 키넥트센서의 정보를 이용해 EKF 알고리즘을 거쳐 사람과 로봇간의 상대위치 및 속도를 추정한다. EKF 알고리즘의 결과를 이용해 실내 환경에서 사람과 같이 근접동반주행을 하기 위한 다양한 모드의 제어 실험을 수행한다. 또한, 모션캡처장비(VICON)를 이용해 알고리즘의 정확도를 검증하였다.

• 한국운동역학회지
• /
• 제19권1호
• /
• pp.107-115
• /
• 2009

본 연구는 다운증후군을 가진 아동($9{\sim}12$세) 9명을 대상으로 12주간의 근력, 평형성, 보행 동작 훈련이 보행과 관련된 운동학적 특성에 미치는 효과를 규명하는 것이다. 근력, 평형성, 보행의 변화를 관찰하기 위해서 훈련이 시작되어 12주가 경과한 시점에서 사전 검사와 동일한 방법으로 보행의 운동학적 변인을 측정하였다. 보행의 운동학적 특성은 3차원 영상분석법을 통하여 산출하였다. 12주간의 근력, 평형성, 보행훈련 후에 골반의 회전이 감소하였으며, 무릎과 엉덩 관절의 굴곡이 증가하였으며, 다리를 스윙할 때 엉덩관절의 외전이 감소하였다. 또한, 분당 보폭 수가 증가하였으며 보폭은 감소하였다. 결론적으로 다운증후군 아동들은 12주간의 근력, 평형성, 보행훈련 후에 보행의 운동학적 변인이 향상되었다.

• 재활복지공학회논문지
• /
• 제11권4호
• /
• pp.349-354
• /
• 2017

본 논문은 개인위생(personal hygiene)을 위한 보조기기(assistive product)의 하나인, 고령자 및 장애인을 위한 높이조절 세면기의 설계 가이드라인을 제안하였다. 본 연구에서는 기존의 세면기와 프로토타입 높이조절 세면기를 이용한 생체역학적 평가를 진행하였다. 65세 이상 남성 5명(age $68.6{\pm}4.3yrs.$, height $169.8{\pm}5.7cm$, weight $70{\pm}7.7kg$)이 피험자로 참가하였으며, 피험자가 세면기 사용시 3차원 동작측정장치를 이용하여 인체각도를 측정하고, 인체모델을 이용하여 요추에 걸리는 모멘트를 추정하여 평가하였다. 이 결과로부터 최적의 높이 조절 가능 범위가 652[mm]에서 1,162[mm]인 설계 가이드라인을 제시하였다. 일반인 5명의 피험자($25.8{\pm}1.8$세, $175.5{\pm}5.8cm$, $74{\pm}15.7kg$)를 대상으로 높이 조절 세면기의 사용시 그 유효성을 평가하였으며, 그 결과 본 논문에서 제시한 높이조절 범위가 타당함을 보였다.

• Journal of Biosystems Engineering
• /
• 제38권1호
• /
• pp.64-71
• /
• 2013

Purpose: The purpose of this study was to select standing posture parameters that have a significant difference according to the severity of spinal deformity, and to develop a novel Cobb angle prediction model for adolescent girls with idiopathic scoliosis. Methods: Five normal adolescents girls with no history of musculoskeletal disorders, 13 mild scoliosis patients (Cobb angle: $10^{\circ}-25^{\circ}$), and 14 severe scoliosis patients (Cobb angle: $25^{\circ}-50^{\circ}$) participated in this study. Six infrared cameras (VICON) were used to acquire data and 35 standing parameters of scoliosis patients were extracted from previous studies. Using the ANOVA and post-hoc test, parameters that had significant differences were extracted. In addition, these standing posture parameters were utilized to develop a Cobb-angle prediction model through multiple regression analysis. Results: Twenty two of the parameters showed differences between at least two of the three groups and these parameters were used to develop the multi-linear regression model. This model showed a good agreement ($R^2$ = 0.92) between the predicted and the measured Cobb angle. Also, a blind study was performed using 5 random datasets that had not been used in the model and the errors were approximately $3.2{\pm}1.8$. Conclusions: In this study, we demonstrated the possibility of clinically predicting the Cobb angle using a non-invasive technique. Also, monitoring changes in patients with a progressive disease, such as scoliosis, will make possible to have determine the appropriate treatment and rehabilitation strategies without the need for radiation exposure.

• 한국운동역학회지
• /
• 제15권3호
• /
• pp.31-49
• /
• 2005

The purpose of this study was to analyze the weight transfer patterns under the different golf swing types which are full swing control swing and putting stroke. Two women golfers participated in this study, one(165cm, 94.3kg)being classified as a low-handicap(LH)player, the other(165cm, 54.5kg) being classified as a high-handicap(HH) player. Both players are right-handed. Two force plates(Kistler, 9286AA) were synchronized with a motion capture system(Qualisys ProReflex MCU240). Anteriorposterior, mediolateral, and vertical forces were used as an indicator of the pattern of swing. Four discrete positions which are address, top of backswing impact, and finish were identified as an event and three phases which are backswing downswing, and follow-through between he events were also identified. The results showed that, at impact, the total force was 1.24BW ring the full swing 1.17BW during the control stroke, 1.00BW during the putting stroke. Depending on the golf swing types, the differences are existed. At impact, the distribution of forces is different with a low-handicap(LH) player and a high-handicap(HH) player. A LH player has 26% in right foot and 74% in left foot during the full swing 49% in right foot and 51% in left foot during the control swing 49% in right foot and 51% in left foot during the putting stroke. A HH, on the other hand, has 74% in right foot and 26% in left foot during the full swing 62% in right foot and 38% in left foot during the control swing 54% in right foot and 46% in left foot during the putting stroke. From address to top of backswing the amount of vertical forces are changed 43:57(right foot: left foot) to 76:24 during the full swing 47:53(right foot: left foot) to 75:25 during the control swing 50:50(right foot: left foot) to 54:46 during the putting stroke. The biggest weight transfer pattern took place in full swing and the control swing is next, and the putting stroke is the final.

• 한국운동역학회지
• /
• 제22권4호
• /
• pp.379-386
• /
• 2012

The aim of this study was to investigate and identify the differences in lower extremity energy dissipation strategies between drop-landing and countermovement-jump maneuvers. Fourteen recreational athletes(Age : $23.3{\pm}2.1years$, Height : $172.3{\pm}4.0cm$, Weight : $69.2{\pm}4.7kg$) were recruited and instructed to perform drop-landing from 45 cm height and countermovement-jump from 45 cm to 20 cm height. The landing phase was taken as the time between initial contact and peak knee flexion. A motion-capture system consisting of eight infra-red cameras was employed to collect kinematics data at a sampling rate of 200 Hz and a force-plate was used to collect GRF data at a sampling rate of 2000 Hz. Paired t-test was performed to determine the difference in kinematics and kinetics variables between each task. During the countermovement-jump task, all of lower extremity joint ROM and the hip joint eccentric moment were decreased and the ankle joint plantarflexion moment was increased than drop-landing task. In the eccentric work during countermovement-jump task, the ankle joint displayed greater while knee and hip joint showed lesser than drop-landing. Therefore, the knee joint acted as the key energy dissipater during drop-landing while the ankle joint contributed the most energy dissipation during countermovement-jump. Our findings collectively indicated that different energy dissipation strategies were adopted for drop-landing and countermovement-jump.

• 한국전문물리치료학회지
• /
• 제26권1호
• /
• pp.67-74
• /
• 2019

Background: Uncontrolled lumbopelvic movement leads to asymmetric symptoms and causes pain in the lumbar and pelvic regions. So many patients have uncontrolled lumbopelvic movement. Passive support devices are used for unstable lumbopelvic patient. So, we need to understand that influence of passive support on lumbopelvic stability. It is important to examine that using the pelvic belt on abdominal muscle activity, pelvic rotation and pelvic tilt. Objects: This study observed abdominal muscle activity, pelvic rotation and tilt angles were compared during active straight leg raise (ASLR) with and without pelvic compression belt. Methods: Sixteen healthy women were participated in this study. ASRL with and without pelvic compression belt was performed for 5 sec, until their leg touched the target bar that was set 20 cm above the base. Surface electromyography was recorded from rectus abdominis (RA), internal oblique abdominis (IO), and external oblique abdominis (EO) bilaterally. And pelvic rotation and tilt angles were measured by motion capture system. Results: There were significantly less activities of left EO (p=.042), right EO (p=.031), left IO (p=.039), right IO (p=.019), left RA (p=.044), and right RA (p=.042) and a greater right pelvic rotation angle (p=.008) and anterior pelvic tilt angle (p<.001) during ASLR with pelvic compression belt. Conclusion: These results showed that abdominal activity was reduced while the right pelvic rotation angle and anterior pelvic tilt angle were increased during ASLR with a pelvic compression belt. In other words, although pelvic compression belt could support abdominal muscle activity, it would be difficult to control pelvic movement. So pelvic belt would not be useful for controlled ASLR.

• The Journal of Korean Physical Therapy
• /
• 제31권2호
• /
• pp.122-128
• /
• 2019

Purpose: This study examined the effects of sagittal spinopelvic alignment on the clinical parameters, motor symptoms, and respiratory function in patients with mild to moderate Parkinson's disease (PD). Methods: This study was a prospective assessment of treated patients (n=28, Hoehn and Yahr (H&Y) stage 2-3) in a PD center. Twenty-eight subjects ($68.5{\pm}5.7yrs$) participated in this study. The clinical and demographic parameters, including age, sex, symptoms duration, treatment duration, and H&Y stage, were collected. Kinematic analysis was conducted in the upright standing posture with a motion capture system. A pulmonary function test (PFT) was performed in the sitting position using a spirometer. The motor symptoms were assessed on part III of the movement disorder society sponsored version of the unified Parkinson's disease rating scale (MDS-UPDRS). SPSS 18.0 was used to analyze the collected data. Results: The exceeding 12 degrees group of the lower trunk showed significantly higher on the clinical parameters than the below 12 degrees group. In addition, the exceeding 12 degrees group of the lower trunk showed a significantly lower forced expiratory volume at one second (FEV1) / forced vital capacity (FVC) (%) and 25-75% forced mid-expiratory flow (FEF) (L/s) than in the below group. On the other hand, there was no difference in the upper trunk and the cervical pelvis between the groups. Conclusion: These findings suggest that the sagittal balance in the lower trunk is related to the clinical parameters and respiratory function, but not the motor symptoms in patients with mild to moderate PD.

• 한국전문물리치료학회지
• /
• 제26권2호
• /
• pp.1-7
• /
• 2019

Background: In previous studies, changes in postural alignment were found when the slope was changed during walking. Downhill walking straightens the trunk by shifting the line of gravity backward. Objects: This study investigated the effect of the downhill treadmill walking exercise (DTWE) on thoracic angle and thoracic erector spinae (TES) activation in subjects with thoracic kyphosis. Methods: A total of 20 subjects with thoracic kyphosis were recruited for this study. All the subjects performed the DTWE for 30 minutes. A surface EMG and 3D motion capture system were used to measure TES activation and thoracic angle before and after the DTWE. Paired t-tests were used to confirm the effect of the DTWE (p<.05). Results: Both the thoracic angle and TES activation had significantly increased after the DTWE compared to the baseline (p<.05). An increase in the thoracic angle indicates a decrease in kyphosis. Conclusion: The DTWE is effective for thoracic kyphosis patients as it decreases their kyphotic posture and increases the TES activation. Future longitudinal studies are required to investigate the long-term effects of the DTWE.