• Korean Journal of Applied Biomechanics
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• v.14 no.3
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• pp.177-189
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• 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.

• Korean Journal of Applied Biomechanics
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• v.22 no.3
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• pp.261-268
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• 2012

The purpose of this study was to qualitatively analyze pressure intensity and the center of pressure(COP) trajectory according to shoe type. Subjects were ten first-year female university students. The EMED-AT 25/D(Novel, Germany) was used to measure pressure intensity and COP trajectory. The COP Excursion Index(CPEI) was used for within subject test design. Independent variables were bare feet and six types of shoes. Dependent variables were center of pressure trajectory and pressure intensity. Barefeet and five toed shoes had a similar pressure intensity and COP trajectory. COP trajectory for all other shoe types showed a medial wobble at the heel. Pressure intensity for all other shoe types was related to the structure of the shoes. In conclusion, different shoe types can not only affect gait, but they can also influence foot deformities, pain, and dysfunction.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.7 no.2
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• pp.47-54
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• 2013

In this paper, we present an inertial sensor-based motion capturing system to measure and analyze whole body movements. This system implements a wireless AHRS(attitude heading reference system) we developed using a combination of rate gyroscope, accelerometer and magnetometer sensor signals. Several AHRS modules mounted on segments of the patient's body provide the quaternions representing the patient segments's orientation in space. We performed 3D motion capture using the quaternion data calculated. And a method is also proposed for calculating three-dimensional inter-segment joint angle which is an important bio-mechanical measure for a variety of applications related to rehabilitation. To evaluate the performance of our AHRS module, the Vicon motion capture system, which offers millimeter resolution of 3D spatial displacements and orientations, is used as a reference. The evaluation resulted in a RMSE of 2.56 degree. The results suggest that our system will provide an in-depth insight into the effectiveness, appropriate level of care, and feedback of the rehabilitation process by performing real-time limbs or gait analysis during the post-stroke recovery process.

• Korean Journal of Applied Biomechanics
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• v.32 no.1
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• pp.17-23
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• 2022

Objective: The aim of this study was to investigate the effect Tiger-step walking on the movement of the lower extremities during walking. Method: Twenty healthy male adults who had no experience of musculoskeletal injuries on lower extremities in the last six months (age: 26.85 ± 3.28 yrs, height: 174.6 ± 3.72 cm, weight: 73.65 ± 7.48 kg) participated in this study. In this study, 7-segments whole-body model (pelvis, both side of thigh, shank and foot) was used and 29 reflective markers and cluster were attached to the body to identify the segments during the gait. A 3-dimensional motion analysis with 8 infrared cameras and 7 channeled EMG was performed to find the effect of tigerstep on uphill walking. To verify the tigerstep effect, a one-way ANOVA with a repeated measure was used and the statistical significance level was set at α=.05. Results: Firstly, Both Tiger-steps showed a significant increase in stance time and stride length compared with normal walking (p<.05), while both Tiger-steps shown significantly reduced cadence compared to normal walking (p<.05). Secondly, both Tiger-steps revealed significantly increased in hip and ankle joint range of motion compared with normal walking at all planes (p<.05). On the other hand, both Tiger-steps showed significantly increased knee joint range of motion compared with normal walking at the frontal and transverse planes (p<.05). Lastly, Gluteus maximus, biceps femoris, medial gastrocnemius, tibialis anterior of both tiger-step revealed significantly increased muscle activation compared with normal walking in gait cycle and stance phase (p<.05). On the other hand, in swing phase, the muscle activity of the vastus medialis, biceps femoris, tibialis anterior of both tiger-step significantly increased compared with those of normal walking (p <.05). Conclusion: As a result of this study, Tiger step revealed increased in 3d range of motion of lower extremity joints as well as the muscle activities associated with range of motion. These findings were evaluated as an increase in stride length, which is essential for efficient walking. Therefore, the finding of this study prove the effectiveness of the tiger step when walking uphill, and it is thought that it will help develop a more efficient tiger step in the future, which has not been scientifically proven.

• Journal of The Korean Society of Integrative Medicine
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• v.5 no.4
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• pp.41-48
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• 2017

Purpose : The purpose of this study was to verify the relationships among the knee adduction moment, hip rotation range, strength of hip rotators, and Foot Posture Index of healthy young adults. Method : Thirty-two healthy adults(24 male, 8 females) participated in this study. Subjects performed 5 walking trials to evaluate the knee adduction moments using a three-dimensional motion analysis system. Hip rotation ranges and hip rotator strengths were measured using a standard goniometer and a handheld dynamometer, respectively. The mean of three trials of clinical tests was used for data analysis. Results : The first peak knee adduction moment was significantly correlated with the hip rotation ranges and hip rotator strengths (P<.05). The second peak knee adduction moment was showed significant correlations with hip external rotation and rotation ratio. There were no correlations between Foot Posture Index and all knee adduction moments (P>.05). Conclusion : This study suggests that imbalances of the range of motion and strength of the internal and external rotation of the hip joint can affect knee adduction moments. The impact may exacerbate musculoskeletal disorders such as osteoarthritis of the knee. Therefore, further studies should be conducted to evaluate the effects of clinical interventions to correct these imbalances on the reduction of the knee adduction moments in patients with knee osteoarthritis.

• Journal of Mechanical Science and Technology
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• v.19 no.spc1
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• pp.237-254
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• 2005

The vast mechanical systems could be classified as closed loop system, open loop system and open & closed (switching) system. In the closed loop system, the kinematics and dynamics of 3-D mechanisms will be reviewed and closed form solutions using the direction cosine matrix method and reflection transformation method will be introduced. In the open loop system, kinematic & dynamic analysis methods regarding the redundant system which has more degrees of freedom in joint space than those of task space are reviewed and discussed. Finally, switching system which changes its phase between closed and open loop motion is investigated with the principle of dynamical balance. Among switching systems, the human gait in biomechanics and humanoid in robotics are presented.

• Journal of Veterinary Science
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• v.21 no.4
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• pp.62.1-62.7
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• 2020

A 5-month old Shih Tzu was diagnosed with congenital elbow luxation and uniapical complex angular deformity of the radius. Single radial oblique and dynamic ulnar osteotomies were performed, using patient-specific 3D-printed osteotomy guide. External skeletal fixation was maintained for three weeks to prevent re-luxation of elbow joint. Three months after the surgery, objective gait analysis indicated markedly improved limb function. In addition, radiograph showed improved congruity of elbow joint and appropriate bone healing. In dogs with congenital radial head luxation and concurrent complex angular deformity, a single oblique osteotomy might be a viable option to preserve bone length and correct the luxation of elbow joint.

• Korean Journal of Applied Biomechanics
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• v.20 no.1
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• pp.91-99
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• 2010

The purpose of this study was to the kinetic variables effects from the use of arch support inserts on low-arched people. We selected 10 people for the research and separated them into 2 groups, 5 people for the normal arched group and 5 people for the low arched group. Each group wear shoes which have a 3 step convertible arch support (level 0, level 2, level 5) and we measured their foot pressure and 3D motion analysis data. As a result, we found that the mean pressure at the heel of the low arched group was decreased when using the arch supports. The arch support induced the correct grounding area for the foot and dispersion of foot pressure. 3D motion analysis found that as the height of the arch support was increased, the movement of the Y-axis(inversion-eversion) was increased to relieve the shock to the heel. The arch support insert limited the range of motion(ROM) of the Z-axis(abduction-adduction) of the low arched person's ankle joint and prevented ankle injury caused by the excessive eversion when walking. Low arched people are seen to be easily tired due to the ineffective shock absorption of the knees and abnormal walking motion. In order to improve the problems, a 3 step convertible arch support(level 5) insert would improve the low-arched people's walking ability. In other words, the low arched people should be expected to walk as well as normal arched people when they wear shoes with the arch support insert.

• Journal of the Korean Society of Physical Medicine
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• v.14 no.1
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• pp.53-61
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• 2019

PURPOSE: This study examined the dynamic range of motion (ROM) of the hip, knee, and ankle joint when wearing different shoe sole lifts, as well as the limb asymmetry of the range according to the leg length discrepancy (LLD) during normal speed walking. METHODS: The participants were 40 healthy adults. A motion analysis system was used to collect kinematic ROM data. The participants had 40 markers attached to their lower extremities and were asked to walk on a 6 m walkway, under three different shoe lift conditions (without an insole, 1 cm insole, and 2 cm insole). Visual3D professional software was used to coordinate kinematic ROM data. RESULTS: Most of the ROM variables of the short limbs were similar under each insole lift condition (p>.05). In contrast, when wearing a shoe with a 2 cm insole lift, the long limbs showed significant increases in flexion and extension of the knee joint as well as; plantarflexion, dorsiflexion, pronation, eversion, and inversion of the ankle joint (p<.05). Of the shoes with the insole lifts, significant differences in all ROM variables were observed between the left and right knees, except for the knee internal rotation (p<.05). CONCLUSION: As the insole lift was increased, more ROM differences were observed between the left and right limbs, and the asymmetry of the bilateral lower limbs increased. Therefore, appropriate interventions for LLD are needed because an artificial mild LLD of less than 2.0 cm could lead to a range of musculoskeletal problems of the lower extremities, such as knee and ankle osteoarthritis.

• Physical Therapy Korea
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• v.20 no.1
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• pp.18-27
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• 2013

The purpose of this study was to compare the ring lock type knee-ankle-foot orthosis (KAFO) with newly developed 4-bar linkage KAFO on the gait characteristics of persons with poliomyelitis clinically. This 4-bar linkage is the stance control type KAFO which provide the stability during stance phase and knee flexion during swing phase. Two subjects participated in this study voluntarily. We provided the customized 4-bar linkage KAFO then asked the subjects to walk in level surface and stairs under the two different KAFO conditions. The characteristics of gait in the persons with poliomyelitis were evaluated using a 3D motion analysis system and force plate. Additionally 6 minute walk test for physiological cost index were conducted using pulse oximeter to measure the energy consumption. In the results of this study, the differences of 4-bar linkage KAFO compared with ring lock type KAFO are as follows: (1) Walking speed, stride length, and step length on level increased in subjects, (2) The gait symmetry was improved by generated knee flexion and decreased pelvic external rotation on level and stairs walking, (3) Decreased vertical excursion of center of mass and pelvic elevation during swing phase was decreased on level, (4) Knee extension moment, hip flexion moment, hip and knee internal rotation moment of non-braced limb were decreased on level walking, (5) Walking speed in 6-minute walk test was increased and physiological cost index was decreased. These findings indicate that 4-bar linkage KAFO compared with ring lock type KAFO is effective in enhancing pattern, endurance, and energy consumption in level surface and stairs walking.