• 대한의용생체공학회:의공학회지
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• 제31권5호
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• pp.344-350
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• 2010

The aim of this study was to investigate the characteristics of the flexion withdrawal reflex modulated during Lokomat treadmill walking in people with spinal cord injury. The influence of the limb position and movement were tested in 5 subjects with chronic spinal cord injury. EMG activities from tibialis anterior and moments of the hip joint elicited by the foot stimulation were examined during Lokomat treadmill walking. To trigger the flexion withdrawal reflex during Lokomat treadmill walking, a train of 10 stimulus pulses was applied at the skin of the medial arch. The TA EMG activity was modulated during gait phase and the largest TA reflex was obtained after heel-off and initial swing phase. During swing phase, TA EMG was 40.9% greater for the extended hip position (phase 6), compared with flexed hip position (phase 8). The measured reflex moment of the hip joint was also modulated during gait phase. In order to characterize the neural contribution of flexion reflex at the hip joint, we compared estimated moments consisted of the static and dynamic components with measured moment of the hip joint. The mean static gains of reflex hip moments for swing and stance phase are -0.1, -0.8, respectively. The mean dynamic gains of reflex hip moments are 0.25 for swing, 0.75 for stance phase. From this study, we postulate that the joint moment and muscle response of flexion withdrawal reflex have the phase-dependent modulation and linear relationship with hip angle and angular velocity for swing phase during Lokomat treadmill walking.

• 한국운동역학회지
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• 제16권3호
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• pp.53-63
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• 2006

The general objective of this study was to investigate biomechanical characteristics of bowling swing using three-dimensional cinematography. This study focused specifically on movements of the upper body segments during a bowling swing. Eight elite female bowling players participated in this study. Subjects performed bowling swing and their performance was sampled at 60 frame/sec using two high-speed video cameras with a synchronizer. After digitizing images from two cameras, the two-dimensional coordinates were used to produce three-dimensional coordinates of the 12 body segments (20 joint reference makers). The obtained three-dimensional coordinates were fed to a custom-written kinematic and kinetic analyses program (LabView 6.1, National Instrument, Austin, TX, USA). The analyses determined the linear and angular kinematic variables of the body segments with which joint force and torque of the lower and upper trunks and the shoulder were estimated based on the Newton-Euler equations. It was found that during the bowling swing the peak linear velocities of the body segments were reached in sequence the trunk, the shoulder, the elbow, the wrist, and the bowl. This result indicates that linear momentum of the lower body and the trunk transmits to the arm segment during the bowling swing. The joint torques of the torso and the arm occurred almost simultaneously, indicating that bowling swing seem to be a push-like motion, rather than a proximal-distal sequence motion in which many of throwing motions are categorized. The ultimate objective of the bowling swing is to release a heavy-weight bowl with power and consistency. Therefore, the bowling swing observed in this study well agrees with that bowlers use the stepping to increase the linear velocity of the bowl, the simple pendulum system and the push-like segmental motion in the torso and the arm segment to enhance the power at the release of the bowl.

• 대한물리의학회지
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• 제3권4호
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• pp.225-233
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• 2008

Purpose : The purpose of this study was to investigate changes of muscle strength, ROM and proprioceptive function as before & after ankle taping in soccer players. For this study fifteen sports club whose had no ankle injuries were volunteered. Methode : Fifteen healthy male in soccer players participated in this study. Biodex pro system3 was used to measure isokinetic muscle strengths at $60^{\circ}$/sec angular velocity. Performances of ankle joint were measured peak torque, total work, average power, total work. To measure proprioceptive function used goniometer. Results : 1. proprioceptive sensation error were significantly differences by before & after taping(p<.05). 2. Compare of total work of dorsi flexion plantar flexion weren't significantly differences by before & after taping(p>.05). 3. Compare of average power of dorsi flexion weren't significantly differences by before & after taping(p>.05). 4. Compare average power of plantar flexion were significantly differences by before & after taping(p<.05). 5. Compare average peak torque of dorsi flexion weren't significantly differences by before & after taping(p>.05). 6. Compare average peak torque of plantar flexion were significantly differences by before & after taping(p<.05). Conclusion : Taping can have propriocetive aberrative angular measure, power & peak torque of plantar flexion were significantly differences. But, total work of dorsi flexion plantar flexion and power & peak torque of dorsi flexion weren't significantly differences.

• The Journal of Korean Physical Therapy
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• 제23권6호
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• pp.37-42
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• 2011

Purpose: The aim of this study is to suggest the basic materials for proposing effective and efficient methods when stretching by measuring isokinetic muscular strength according to static, dynamic and PNF stretching. Methods: This study was conducted on 45 healthy persons (male and female) in their twenties who are attending universities. The subjects are randomly divided into three (3) groups, and static stretching is applied in group 1, dynamic stretching is applied in group 2 and PNF stretching is applied in group 3. After carrying out static, dynamic and PNF stretching, peak torque was measured using isokinetic muscular strength measurement. Results: According to the results, at $60^{\circ}$/sec and $180^{\circ}$/sec isokinetic peak torque of the knee joint according to types of stretching, the largest changes were shown in Group 2 extension and flexion, and the least changes were shown in Group 1. There were significant differences among the three groups (p<0.05), and the result of after-analysis by LSD showed that there were significant differences between Groups 1 and 2, and Groups 1 and 3 (p<0.05). Conclusion: The intention of this study was to determine the peak torque using Cybex after applying three stretching methods to hamstring muscles, and the case of dynamic and PNF stretching was found to be more significant in both the $60^{\circ}$/sec and $180^{\circ}$/sec angular speeds than that of static stretching. Using the results of such studies, if dynamic and PNF stretching are applied together with warming-up before performing sports, the risk of suffering wounds would reduce and the exactness of sports would increase.

• 한국운동역학회지
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• 제31권4호
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• pp.297-307
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• 2021

Objective: The aim of this study was to analyze kinetic variables between thermotherapy and dynamic warm-up during drop-landing. Method: Twenty male healthy subjects (Age: 21.85 ± 1.90 years, Height: 1.81 ± 0.06 cm, Weight: 68.5 ± 7.06 kg) underwent three treatments applied on the thermotherapy of femoral muscles and a dynamic warm-up. The thermotherapy was performed for 15 minutes while sitting in a chair using an electric heating pad equipped with a temperature control device. Dynamic warm-up performed 14 exercise, a non-treatment was sitting in a chair for 15 minutes. Core temperature measurements of all subjects were performed before landing at a height of 50 cm. During drop-landing, core temperature, joint angle, moment, work of the sagittal plane was collected and analyzed. All analyses were performed with SPSS 21.0 and for repeated measured ANOVA and Post-hoc was Bonferroni. Results: Results indicated that Thermotherapy was increased temperature than other treatments (p = .000). During drop-landing, hip joint of dynamic warm-up was slower for angular velocity (p < .005), and left ankle joint was fastest than other treatments (p = .004). Maximum joint moment of dynamic warm-up was smaller for three joints (hip extension: p = .000; knee flexion/extension: p = .001/.000; ankle plantarflexion: p = .000). Negative work of dynamic warm-up was smaller than other treatments (p = .000). Conclusion: In conclusion, the thermotherapy in the local area doesn't affect the eccentric contraction of the thigh. The dynamic warm-up treatment minimized the joint moment and negative work of the lower joint during an eccentric contraction, it was confirmed that more active movement was performed than other treatment methods.

• 한국체육학회지인문사회과학편
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• 제54권5호
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• pp.829-840
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• 2015

본 연구는 정상시를 가진 정상인을 대상으로 입체시 부족을 유발하여 장애물 보행 시 발생될 것으로 생각되는 하지관절의 운동 변화에 대한 운동학적 분석과 지면반력의 변화를 고찰하는 것이다. 본 연구의 대상자는 입체시 테스트를 거쳐 통과한 18명이 연구에 참여하였다(age: 22.1±2.7 years, height: 176.8±4.4 cm, weight: 67.6±5.8 kg). 3차원 동작분석 시스템과 지면반력기를 이용하여 분석한 결과는 다음과 같다. 보행속도는 장애물 보행 시 느리게 나타났다. 고관절 각변위는 대부분 보행구간에서 장애물 보행 시 굴곡이 크게 나타났다. 무릎관절 각변위는 모든 보행구간에서 장애물 보행 시 굴곡이 크게 일어났고, TO와 FC2에서 입체시 감소의 영향으로 굴곡이 크게 나타났다. 발목관절 각 변위는 FC2에서 장애물 보행 시 굴곡이 크게 나타났다. 몸통기울기는 MSt, TO, MSw에서 장애물 보행 시 신전이 크게 나타났다. 지면반력은 Fx 값(내외측힘)에서 차이가 나타나지 않았지만, Fy 값(전후힘)에서 좌우발 모두 장애물 보행 시 전방 최대힘(추진력)이 크게 나타났고, 후방 최대힘(제동력)은 오른발은 입체시부족 보행 시 크게 나타났으며, 왼발은 장애물 보행 시 크게 나타났다. Fz 값(수직힘)은 최대힘-1과 최대힘-2에서 좌우발 모두 장애물 보행 시 최대 힘이 크게 나타났고, 계곡힘에서 오른발은 입체시부족 보행이 정상시 보행보다 작은힘이 나타났다.

• 한국운동역학회지
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• 제24권1호
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• pp.51-57
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• 2014

The purpose of this study was to compare and analyze kinetic variables of lower limbs according to types of ankle taping in drop landing. For this, targeting seven male basketball players (average age: $20.8{\pm}0.74yrs$, average height: $187.4{\pm}3.92cm$, average weight: $79.8{\pm}7.62kg$) with no instability of ankle joints, the drop landing motion was conducted according to three types of inelastic taping (C-type), elastic taping (K-type), and no treatment (N-taping). Based on the result, the next conclusion was reached. First, the effect of taping for the players with stable ankles was minimal and the high load on ankle joints offset the fixing effect of inelastic taping. Thus the inelastic taping for the players with stable ankles did not have an effect on the control of dorsal flexion during one-foot landing. Second, increasing angular velocity by increasing the movable range of knee joints disperses impact forces, yet inelastic taping restricted the range of knee joint motion and at the same time increased angular velocity, adding to a negative effect on knee joints. Third, inelastic taping induced inefficient motion of Lower limbs and unstable impact force control of ankle joints at the moment of landing and produced maximum vertical ground reaction force, which led to an increase of load. Therefore, inelastic ankle taping of players whose jump actions occur very often should be reconsidered. Also, it is thought that this study has a great meaning in proving the problem of inelastic taping related to knee pain with unknown causes.

• 한국산학기술학회논문지
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• 제16권2호
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• pp.970-977
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• 2015

본 연구의 목적은 보아의 넘버원 댄스 핵심동작의 생체역학적 3차원분석이며 보아의 전문 안무가가 실험에 참가하였다. 핵심동작의 관절 동작범위는 견관절과 주관절의 전후회전, 분절 동작범위는 몸통과 골반의 좌우회전이 가장 크며 몸통이 골반보다 더 크다. 무게중심이동 속도는 상하방향이 가장 빠르고 좌우, 전후방향 순이다. 최대각속도는 상지관절의 견관절과 주관절 및 하지관절의 고관절과 슬관절의 전후회전에서 가장 크게 나타났으나 족관절의 동작범위와 각속도는 거의 생성되지 않았다. 그리고 최대 회전파워는 상지 견관절과 하지 슬관절을 중심으로 원위분절로 갈수록 작게 나타나고 회전력은 고관절 외전모멘트가 가장 크고 슬관절은 신전모멘트가 크게 나타났다.

• 한국운동역학회지
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• 제15권1호
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• pp.177-195
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• 2005

The purpose of this study was to analyze the kinematic variables of ankle joints and EMG signal of the lower limbs muscle activity for the different walking speed. The subjects were 6 males of twenties. It was classified into three different walking speed-0.75m/s, 1.25m/s, 1.75m/s. The walking performances were filmed by high speed video camera and EMG signal was gained by ME3000P8 Measurement Unit. Tibialis anterior(TA), Gastrocnemius medial head(GM), Gastrocnemius lateral head(GL), Ssoleus(SO) were selected for the dorsiflexion and plantarflexion of the ankle joint. The result of this study were as follows: 1. In the gait cycle, The time parameters for the phases were showed significant difference without the terminal stance phase and terminal swing phase for the different walking speed. 2. The angle of ankle joint was no significant difference for each time point and MDF, MPF but increasing walking speed the angle had the increasing pattern slightly. 3. The angular velocity of ankle joint was showed the significant difference for LHC, RTO, RKC, LHU, MPF and MDF point along the walking speed. 4. TA was showed about 2-3 times muscle activity at the 1.75m/s than 1.25m/s in some phases. And it was showed the similar muscle activity between the 0.75m/s and 1.25m/s but, showed a little much muscle activity in the 0.75m/s. GM was showed about 2-3 times muscle activity in the 1.75m/s than 1.25m/s, and even much muscle activity at the 0.75m/s than 1.25m/s in some phases. GL was showed increasing pattern of muscle activity specially in the initial swing phase as the walking speed increased. SO was showed about 3 times muscle activity in the 1.75m/s than 1.25m/s during the plantarflexion of ankle joint. It was showed the similar muscle activity between the 0.75m/s and 1.25m/s but, showed a little much muscle activity in the 1.25m/s.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1500-1503
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• 2003

One of the main goals in the rehabilitation of SCI patients is to enable the patient to stand and walk themselves. We are developing high-thrust powered gait orthosis(PGO) that use air muscle actuator(shadow robot Co., UK) to be assisted gait and rehabilitation purposes of them. We made of PD controller and measured hip joint angle by its load and the pressure to control air muscle of PGO. As a results, maximum flexion angle of hip joint is $20^{\circ}$, and angular velocity is 30.4${\pm}2.5^{\circ}/sec$, and then delay time of system was average 0.62${\pm}$0.03s. As the hip flexion angle and the pelvic angle is decreased during the gait with PGO, the patient can walk faster. By using the PGO, the energy consumption can also be decreased. therefore, the proposed PGO can be a very useful assitive device for the paraplegics to walk.