• The Journal of Korean Physical Therapy
• /
• 제27권5호
• /
• pp.304-310
• /
• 2015

Purpose: The purpose of this study was to examine the change in the kinematics and kinetics of the knee joint depending on high-heeled shoes during sit-to-stand (SitTS) task. Methods: Nineteen healthy females participated in this study. The subjects performed the SitTS task wearing high-heeled shoes and barefoot. The experiment was repeated three times for each task with foot conditions. The kinematics and kinetics of the knee joint were measured and analyzed using a 3D motion analysis system. Results: The result of this study showed kinematic and kinetics differences in knee joints during the SitTS task based on high-heeled shoes. Significant differences in knee flexion angle were observed during SitTS. The knee extensor force showed statistically significant differences during SitTS tasks. At the initial of SitTS, the knee flexor and extensor moment showed significant differences. The knee extensor moment showed statistically significant differences at the terminal of SitTS. At the maximum of SitTS, the knee extensor moment showed statistically significant differences. Conclusion: Therefore, wearing high-heeled shoes during SitTS movements in daily life is considered to influence knee joint kinematics and kinetics due to the HH, suggesting the possibility of increased risk of patellofemoral pain, and knee osteoarthritis caused by changes in loading of the knee joint.

• 한국의류학회지
• /
• 제22권1호
• /
• pp.18-28
• /
• 1998

The objective of the study was to observe the difference of moving function of lower-limb in relation to the length 8t silouutte of tight skirt. Four types of tight skirts (2 lengths$\times$2 silhouettes) were made for the experiment. The surface E.M.S in four different locations of leg muscles (Rectos femoris, Semitendinosus, Tibalis anterior, Gastrocnemius) were recorded. The sensory test to decide how to be fatigued after longtime wearing of skirt were examined two times per a day. The fatigue sensory test was scored a Likert-type scale (1= no fatigue, 5=heavy fatigue). Data were analyzed by the repeated ANOVA ann Duncan's multiple range test with use of SAS Package. The main results of this study were as follows: 1. As a result of analysis of E.M.S., in case of walking on the floor there was significant difference in the moving function according to length of skirt and in case of stepping there was significant differnce in three ways (length silhouette, length, silhouette). 2. From the record of walking the step-length, stride-length, step-width were found affected by garments, but foot-angle was not affected. The moving function of slim type was lower than that of semi type and that of ankle-length skirt was lower than that of knee-length skirt. 3. The results of the sensory test agreed with that of E.M.G and Footprints.

• 디지털산업정보학회논문지
• /
• 제13권4호
• /
• pp.81-90
• /
• 2017

This paper presents a smart seat for correction of driver posture while driving. We introduce good postures with seat height, seat angle, head height, back of knees, distances of foot pedals, tilt of seat, etc. There have been some studies on correction of good posture while driving, effects of driving environment on driver's posture, sitting strategies based on seating pressure distribution, estimation of driver's standard postures, and others. However, there are a few studies on guide of good postures while driving for problem of driver's posture using machine leaning. Therefore, we suggest a smart seat for correction of driver's posture based on machine leaning, 1) developed the system to get postures by 10 piezoelectric effect element, 2) collect piezoelectric values from 37 drivers and 28 types of cars, 3) suggest 4 types of good postures while driving, 4) analyze test postures by kNN. As the results, we can guide good postures for bad or problems of postures while driving.

• 한국운동역학회지
• /
• 제30권1호
• /
• pp.83-91
• /
• 2020

Objective: The study aimed to develop a functional performance index that evaluates the functional performance of Parkinson's patients, i.e., to integrate biomechanical measurements of walking, balance, muscle strength and tremor, and to use multiple linear regression with stepwise methods to identify the most suitable predictors for the progression of disease. Method: A total of 60 subjects were tested for sub-variables of four factors: walking, balance, isometric strength and hand tremors. Potential independet variables were extracted through correlation analysis of the sub-variables and dependent variables, Hoehn & Yahr scale. And then, a stepwise multiple regression analysis using the potential independent variables was performed to identify predictor of Hoehn & Yahr scale. Results: First, the results of the study showed that physical composition and gait had a relatively more correlated with the progression of the disease, compared to balance and hand tremor. Second, Parkinson's functional performance is characterized by dynamic pattern of walking, such as foot clearance and turning angle (TA) of walking, and a high-explained regression model is completed. Conclusion: The study emphasized the importance of walking variables and body composition in minor pathological features compared to Parkinson's patient's balancing ability and hand tremor. Specifically, it revealed that dynamic walking patterns functionally characterize patients. The results are worth considering when assessing functional performance related to the progression of the disease at the site.

• 제어로봇시스템학회논문지
• /
• 제11권1호
• /
• pp.58-66
• /
• 2005

Usual human gait can be modeled as continual impact phenomenon that happens due to the topological change of the kinematic structure of the two feet. The human being adapts his own control algorithm to minimize the ill effect due to the collision with the environment. In order to operate a Humanoid robot like the human being, it is necessary to understand the physics of the impact and to derive an analytical model of the impact. In this paper, specially, we focus on impact analysis of the kicking motion in playing soccer. At the instant of impact, the external impulse exerted on the ball by the foot is an important property. Initially, we introduce the complete external impulse model of the lower-extremity of the human body and analyze the external impulses for several kicking postures of the lower-extremity. Secondly, a trajectory-planning algorithm of a ball, in which the initial velocity and the launch angle of the ball are calculated for a desired trajectory of the ball, will be introduced. The aerodynamic effect such as drag force and lift force is also considered. We carry out numerical simulation and experimentation to verify the effectiveness of the proposed analytical methodology.

• 한국운동역학회지
• /
• 제22권1호
• /
• pp.1-7
• /
• 2012

The purpose of this study was to investigate the pattern change of throwing in baseball after 15 weeks of participation in baseball class, by examining ball speed, trunk and upper body angles. The comparison was with 6 university students that haven't had any experience in baseball. 8 infra red cameras and 2 force platforms were used to collect the data. First, there was an increase in the speed of the ball after the class. Second, there was no significant difference in the allocated phases during the throw before and after class. Third, the release point was lower and more in front. Forth, there was an increase in the knee flexion at the left foot landing and release point. Finally, there was an increase in the maximum shoulder external rotation and pelvis angle. It is recommended that the coordination between the segments should be investigated to improve our understanding of the learning of throwing in future research.

• 대한물리치료과학회지
• /
• 제11권2호
• /
• pp.5-17
• /
• 2004

The purpose of this study was to investigate the relationship between normal adults' resting calcaneal stance position(RCSP) and postural sway. Subjects were 70 normal adults(34 men and 36 women) in their twenties who attend S. University. Postural sway during a single limb stance was measured using the CMS 10 Measuring System when subjects positioned on the balance trainer in their bare foot. RCSP while subjects were standing on the glass plate was measured using the angle tinder after subjects were positioned in prone to divide equally lower leg and calcaneus using the goniometer. The result was as follows. There were significant weak positive correlations between RCSP and postural sway(r=0.362, p<0.01), the leg of the small RCSP within a subject has the small postural sway index($X^2=43.758$, p<0.001). There was no significant difference between groups of rearfoot valgus(RCSp<$2^{\circ}$) and those of rearfoot varus (RCSp>$2^{\circ}$) in the postural sway. In conclusion, there is a weak relationship between increasing the absolute value of RCSP and increasing postural sway.

• 대한의용생체공학회:의공학회지
• /
• 제30권3호
• /
• pp.247-254
• /
• 2009

We studied the postural response induced by plantar sole vibration with various frequencies(20, 60, 100Hz) and vibration zone(the anterior and posterior foot zone) of both soles during standing. Eight healthy young adults were exposed to 15s periods of plantar sole vibration while blindfolded. Body sway(COM, center of mass), the angle of neck, trunk, hip, knee, ankle and EMG of four lower limb muscles(tibialis anterior, lateral and medial gastrocnemial, soleus muscle) were recorded during 15s plantar sole vibration using 3D motion analysis system. Simulating each zone separately resulted in spatially oriented body tilts; oppositely directed backward and forward, respectively, the amplitude of which was proportional to the vibration frequency. EMG activity of lower limb muscles also varied according to the direction of the vibration zone and linearly according to the frequency. These findings led us to consider the plantar sole vibration as useful method of postural balance control and adjustment.

• 대한전기학회논문지:시스템및제어부문D
• /
• 제52권8호
• /
• pp.506-509
• /
• 2003

This paper describes the possibility of analyzing gait pattern from the changes of the lower leg electrical impedance. This impedance was measured by the four-electrode method. Two current electrodes were applied to the thigh, knee, and foot., and two potential electrodes were applied to the lateral, medial, and posterior position of human leg. The correlation coefficients of the joint angle and the impedance change from human leg movement was obtained using a electrogoniometer and 4ch impedance measurement system developed in this study. 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. The correlation coefficients of the ankle, knee, and the hip movements were -0.913, 0.984 and 0.823, respectively. From such features of the human leg impedance, it has been made clear that different movement patterns exhibit different impedance patterns and impedance level. This system showed feasibility that lower leg movement could be easily measured by impedance measurement system with a few skin-electrodes.

• 한국운동역학회지
• /
• 제23권3호
• /
• pp.235-243
• /
• 2013

The purpose of this study was to analyse scientific according to period of rehabilitation training of ACL patients. ACL patients seven subjects participated in this study. Gait (1.58 m/sec) analysis was performed by using a 3-D Cinematography, a Zebris system and a electromyograph system. The data were analyzed by paired t-test. The joint angles were recorded from the ankle, knee, hip joints. Peak max dorsi-flexion and peak max plantar-flexion identified significant differences (p<0.05). Another angles were no significant difference. Vertical force (Fz) and max pressure variables improved 6 month RTP better than 3 month RTP. EMG were collected from 4 muscles (rectus femoris, biceps femoris, gastrocnemius, tibialis anterior) with surface electrides in gait system. EMG signals were rectified and smoothed data. EMG signas were no significant difference but they also improved 6 month RTP better than 3 month RTP. More research is necessary to determine exactly what constitutes optimal rehabilitation training period for ACL patients.