• International journal of advanced smart convergence
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• 제9권2호
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• pp.49-57
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• 2020

We have not identified on what gender difference during gait at a pace of one's preferred velocity effects on the function of bilateral lower limb. This study was undertaken to investigate a difference of gait strategy by gender during gait at a one's preferred velocity of participants of adult male and female (n=20). Cinematographic data for motion analysis, ground reaction force (GRF) variables, and muscle volume of lower limb were analyzed. Significant difference of variables on movement of center of mass whole body, joint angle and moment of lower limb, and ground reaction force were tested by 2-way ANOVA analysis (P<0.05). Male group showed more muscle volume than female, and both showed more volume in dominant leg than non-dominant. Main effect by bilateral leg during gait showed higher difference in right than left leg in change of vertical position of center of mass (maximal, minimal). Main effect by gender in vertical change of position and velocity of center of mass showed higher difference in male than female (maximal, minimal). Hip joint showed more flexed and extended angle in male than female, and also dorsiflexion of ankle and flexion moment of knee and hip joint showed higher in male than female group. Therefore, this result was assumed that dominant showed furthermore more contribution for propulsive function than non-dominant leg. Gender difference showed in strategy controlling of biomechanical characteristics, and perhaps influenced by muscle volume.

• 한국운동역학회지
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• 제31권1호
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• pp.64-71
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• 2021

Objective: This study investigated the different in isokinetic peak strength of the knee joint, and kinetics and kinematics in drop landing pattern of lower limb between the patellofemoral pain syndrome (PFPS) patients and normal. Method: 30 adult females were divided into the PFPS (age: 23.13±2.77 yrs; height: 160.97±3.79 cm, weight: 51.19±4.86 kg) and normal group (age: 22.80±2.54 yrs, height: 164.40±5.77 cm, weight: 56.14±8.16 kg), with 15 subjects in each group. To examine the knee isokinetic peak strength, kinematics and kinetics in peak vertical ground reaction force during drop landing. Results: The knee peak torque (Nm) and relative strength (%) were significantly weaker PFPS group than normal group. In addition, PFPS group had significantly greater hip flexion angle (°) than normal group. Moreover, normal group had significantly greater moment of hip abduction, hip internal rotation, and left ankle eversion than PFPS group, and PFPS group had significantly greater moment of knee internal rotation. Finally, there was significant differences between the groups at anteroposterior center of pressure. Conclusion: The PFPS patients had weakened knee strength, and which can result in an unstable landing pattern and cause of more stress in the knee joints despite to effort of reduce vertical ground reaction force.

• Physical Therapy Rehabilitation Science
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• 제10권2호
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• pp.98-105
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• 2021

Objective: The purpose of this study was to examined the kinematic relationship and differences through the range of motion (ROM), muscle activity, and vertical ground reaction force (VGRF) during forward and backward lunge movements, which are effective in improving muscle strength and balance ability of the lower extremities, and to provide clinical information on more efficient lunge movements. Design: Cross-sectional study Methods: Fifteen adult males who met the selection criteria were tested for their dominant feet.Forward and backward lunges were then performed, and the ROM, muscle activity, and VGRF were measured for kinematic analysis during the lunge movement.The differences betweenthe forward lunge and backward lunge intervention were examined using a paired t-test. Results: A significant increase in the ROM of the knee and ankle was observed during the forward and backward lunges (p<0.05). In addition, in terms of the muscle activity, the peak values of the vastus medialis oblique (VMO) and VGRF also showed a significant increase in the forward lunge compared to the backward lunge (p<0.05). Conclusions: This study showed an increase in VGRF peak value, knee and ankle ROM, and VMO muscle activity during forward lunge. Based on these results, it is considered necessary to apply differently depending on the direction of progress in consideration of the musculoskeletal situation and physical ability during the lunge movement.

• 한국재난정보학회 논문집
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• 제19권1호
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• pp.31-43
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• 2023

연구목적: 본 연구에서는 탄소성해석과 수치해석의 차이점 분석과 해석 결과치의 유사한 경향을 도출하기 위한 설계지반정수 재산정 방법의 연구를 수행하였다. 연구방법: 얕은굴착과 깊은굴착에 따라 벽체변위가 같아지는 시점에서의 지반반력계수와 지반변형계수의 관계식을 유도하였다. 연구결과: 계측결과를 바탕으로 역해석을 진행하여 현장지반에 맞는 지반물성을 재산정하고 도출된 식과 문헌식을 이용하여 벽체변위에 대한 비교·검증한 결과 제안식이 가장 유사한 값을 나타내고 있었다. 결론: 제안식을 이용하면 설계시 실제와 가장 비슷한 지반물성치를 유추할 수 있어 실무에 도움이 될 것이다.

• The Journal of Korean Physical Therapy
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• 제26권2호
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• pp.117-122
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• 2014

Purpose: The purpose of this study was to compare the effects of force of ipsilateral versus contralateral cane usage on knee moments in healthy young adults. Methods: A convenience sample of 10 subjects volunteered for this study. Subjects walked over a force plate under three different conditions; unaided and ipsilateral cane and contralateral cane. Analysis of data on moment of the knee joint and ground reaction force was performed using the OrthoTrak program. Results: Flexion moment of the knee was decreased with the contralateral cane, but increased with the ipsilateral cane compared with normal gait. Extension moment of the knee was decreased with the contralateral cane compared with normal gait(p<0.05) and it was showed a greater decrease with the contralateral cane than with the ipsilateral cane gait(p=0.00). Valgus moment of the knee joint was increased with the ipsilateral cane but decreased with the contralateral cane. Vertical ground peak force was decreased with the ipsilateral cane compared with normal gait (p<0.05). Conclusion: The following conclusions were drawn from our data. Contralateral cane gait is more efficacious for persons with weakness of knee extensors, however, for a patient with varus deformity, the cane should be used in the ipsilateral hand.

• 한국운동역학회지
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• 제21권2호
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• pp.173-179
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• 2011

This study aims to analyse difference in biomechanical factors between dominant legs and recessive ones according to muscular imbalance during drop landing targeting talented children in sports. The subjects of the study were ten primary students who are attending to Sports Program for Talented Children organized by C university (age: $12.28{\pm}0.70$ year, height: $1.52{\pm}0.11$ m, and weight: $45.2{\pm}4.9$ kg). Strength legs were classified into dominant side and strengthless legs were classified into non-dominant legs. For three-dimensional analyses of the data collected, 6 video cameras(MotionMaster200, Visol, Korea) were used. To analyse ground reaction force, two force platforms(AMTI ORG-6, MA) were used and to analyse electromyograghy a 8-channeled wireless Noraxon Myoresearch made in USA was used at 1000 Hz for sampling. As a result, it was discovered that the dominants legs controlled knee bending motions more stably than strengthless legs as the maximum vertical ground reaction force was significantly high in dominant legs(p<.05), and joint moment of knee joints of the dominant legs was high(p<.05). Therefore, this study suggested that injury prevention program focusing on muscular balance as well as the existing sports programs for talented children should be developed based on results of the study and it is expected that the results will be useful for improvement of sports programs for talented children.

• 한국운동역학회지
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• 제27권1호
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• pp.1-7
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• 2017

Objective: The purpose of this study was to analyze the relationship between ground reaction force (GRF) and attack time according to the position of hand segments during counter attack in Kendo. Method: The participants consisted of 10 kendo athletes (mean age: $21.50{\pm}1.95yr$, mean height: $175.58{\pm}5.02cm$, mean body weight: $70.96{\pm}9.47kg$) who performed standard head strikes (A) and counter attack with a preferred hand position of +10 cm (B), 0 cm (C), and -10 cm (D). One force-plate (AMTI-OR-7., USA) was used to collect GRF data at a sample rate of 1,000 Hz. The variables analyzed were the attack time, medial-lateral GRF, anterior-posterior GRF (AP GRF), peak vertical force (PVF), and loading rate. Results: The total attack time was shorter in types A and C than in types C and D. The AP GRF, PVF, and loading rate had significantly higher forces in types C and D than in types A and C. The attack time (bilateral and unilateral leg support and total) was positively correlated with the GRF variables (vertical GRF and loading rate) during the counter attack in Kendo (r = 0.779 [$R^2=0.607$], p < 0.001). Conclusion: The positions of the hand segments can be changed by various conditions of the opponent in Kendo competitions; however, the position preferred by an individual can promote the successful ratio of the counter attack.

• 한국운동역학회지
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• 제29권4호
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• pp.255-261
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• 2019

Objective: The purpose of this study was to investigate differences of shock attenuation strategies between double-leg and single-leg landing on sagittal plane using statistical parametric mapping. Method: Nine healthy female professional soccer players (age: 24.0±2.5 yrs, height: 164.9±3.3 cm, weight: 55.7±6.6 kg, career: 11.2±1.4 yrs) were participated in this study. The subjects performed 10 times of double-leg and single-leg landing from the box of 30 cm height onto force plates respectively. The ground reaction force, angle, moment, angular velocity, and power of the ankle, knee, and hip joint on sagittal plane was calculated from initial contact to maximum knee flexion during landing phase. Statistical parametric mapping was used to compare the biomechanical variables of double-leg and single-leg landing of the dominant leg throughout the landing phase. Each mean difference of variables was analyzed using a paired t-test and alpha level was set to 0.05. Results: For the biomechanical variables, significantly increased vertical ground reaction force, plantarflexion moment of the ankle joint, negative ankle joint power and extension moment of the hip joint were found in single-leg landing compared to double-leg landing (p<.05). In addition, the flexion angle and angular velocity of the knee and hip joint in double-leg landing were observed significantly greater than single-leg landing, respectively (p<.05). Conclusion: These findings suggested that negative joint power and plantarflexion moment of the ankle joint can contribute to shock absorption during single-leg landing and may be the factors for preventing the musculoskeletal injuries of the lower extremity by an external force.

• 한국전문물리치료학회지
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• 제13권4호
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• pp.79-86
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• 2006

The purpose of the current experiment was to describe interlimb coordination when swing limb conditions are being manipulated by constraining step length or by adding a 5 or 10 pound weight to the swing limb distally. Subjects were asked to begin walking with the right limb to land on the primary target (normal step length) that is 10 cm in diameter. However, if, during movement, the light was illuminated, then the subject had to step on one of the secondary targets (long and short step length). These three step length conditions were repeated while wearing a 5 pound ankle weight and then when wearing a 10 pound ankle weight. Ground reaction force (GRF) data indicated that there were changes in the forces and slopes of the swing and stance Fx GRFs. Long stepping subjects had to increase the propulsive force required to increase step length. Consequently, swing and stance toe-off greatly increased in the long step length condition. Short step length subjects had to adequately adjust step length, which decreased the speed of gait initiation. Loading the swing limb decreased the force and slope of the swing limb. Swing and stance toe-off was longest for the long step length condition, but there was a small difference of temporal events between no weight and weight condition. It appears that subjects modulated GRFs and temporal events differently to achieve the peak acceleration force of the swing and stance limb in response to different tasks. The findings from the current study provide preliminary data, which can be used to further investigate how we modulate forces during voluntary movement from a quiet stance. This information may be important if we are to use this or a similar task to evaluate gait patterns of the elderly and patient populations.

• 한국운동역학회지
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• 제28권1호
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• pp.1-8
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• 2018

Objective: The purpose of this study is to investigate the differences in biomechanical variables of golf driving motion according to gender. Method: A total of 21 healthy golfers (11 men and 10 women) who have more than 5 years of professional experience and have been registered in the Korea Golf Association was recruited. A 250-Hz 8-camera motion capture system (MX-T20, Vicon, LA, USA) was used to capture the motion trajectories of a total of 42 reflective markers attached to the golfer's body and club. Moreover, two 1,000-Hz AMTI force plates (AMTI OR6-7-400, AMTI, MA, USA) were used to measure the ground reaction force. The mean and standard deviation for each parameter were then calculated for both groups of 21 subjects. SPSS Windows version 23.0 was used for statistical analysis. The independent t-test was used to determine the differences between groups. An alpha level of .05 was utilized in all tests. Results: There were differences in joint angles according to gender during golf driver swing. Men showed a statistically significantly higher peak joint angle and maximum range of angle in sagittal and frontal axis of the pelvis, hip, and knee. Moreover, women's swing of the pelvis and hips was found to have a pattern using the peak joint angle and range of angle in the vertical axis of the pelvis and hip. There were the differences in peak joint moment according to gender during golf driver swing. Men used higher joint moment in the downswing phase than women in the extensor, abductor, and external rotator muscles of the right hip; flexor and adductor muscles of left hip joint; and flexor and extensor muscles of the right knee. Conclusion: This result reveals that male golfers conducted driver swing using stronger force of the lower body and ground reaction force based on strength of hip and thigh than female golfers.