• Journal of the Korean Society of Physical Medicine
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• v.9 no.1
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• pp.125-132
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• 2014

PURPOSE: This study aims to determine the optimal knee joint angle and hip joint angle for minimizing the cervical muscle tension and maximizing the muscle activity of the trunk during the bridging exercise for trunk stabilization. METHODS: The bridging exercise in this study included seven forms of exercise: having a knee joint flexion angle of $120^{\circ}$, $90^{\circ}$, $60^{\circ}$, $45^{\circ}$ and hip joint abduction angle of $15^{\circ}$, $10^{\circ}$, $5^{\circ}$. The posture of the bridging exercise was as follows. To prevent the increase of hyper lumbar lordosis during the bridging exercise, the exercise was practiced after maintaining the lumbar neutral position through the pelvic posterior tilting exercise. RESULTS: The abduction angles did not result in statistically significant effects on the cervical erector, external oblique, rectus abdominis and erector spinae muscles. However, in relation to the knee joint angles, during the bridging exercise, statistically significant results were exhibited. CONCLUSION: The knee joint angle affected the muscle activity of the neck muscle. The greater the knee joint angle, the lower the load placed on the neck muscle. In contrast, the load increased as the knee joint angle decreased. In addition, the muscle activity of the neck muscle and trunk muscle increased as the knee joint angle decreased.

• Physical Therapy Rehabilitation Science
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• v.10 no.2
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• pp.205-211
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• 2021

Objective: This study aimed to identify the effects of assuming different knee angles and hip abduction during bridge exercise and hip thrust exercise on lower body muscle activity. Design: Cross-sectional study Methods: Thirty-three healthy adults (18 men and 15 women) were instructed to perform the bridge and hip thrust exercises while randomly assuming 120°, 90° and 60° of knee flexion and 0° and 30° of hip abduction. EMG data (%maximum voluntary isometric contraction) were recorded three times from the erector spinae (ES), gluteus maximus (GM) and biceps femoris (BF) muscles of participant's dominant side and the mean values were analyzed. Results: The results showed that, during the hip thrust compared to the bridge exercise, there was significantly greater gluteus maximus muscle activity in all hip conditions while the biceps femoris activity was significantly less, and the erector spinae muscle activity was significantly greater with 30° of hip abduction (p<0.05). With all exercises, the erector spinae and the biceps femoris exhibited significantly greater muscle activity with 60° of knee flexion compared to 90° and 120° of knee flexion (p<0.05), and significantly greater muscle activity with 90° compared to 120° of knee flexion (p<0.05). In the case of the gluteus maximus, greater muscle activity was exhibited with 120° compared to 60° of knee flexion with all hip abduction conditions (p<0.05). Conclusions: It was effective for muscle activation of main agonists such as the gluteus maximus and erector spinae during thrust exercise, and the change in knee flexion angle was effective for muscle activation of the gluteus maximus. Therefore, it is considered that this study can be used as a selective indicator of the target movement angle during hip strengthening exercise for specific muscles.

• The Journal of Korean Physical Therapy
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• v.13 no.2
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• pp.453-458
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• 2001

The aim of this study is to present the basic reference data of age and specific gait parameters for Parkinson's Disease Patients. The basic gait parameters were extracted from 5 patients, 5 men and 65 years of age using VICON 512 Motion Analyzer. The temporal gait parameters and kinematic parameters is data of Parkinson's Disease Patients. The results were as follows; 1. The cadence, velocity, stride length decreased and single limb support period, double limb support period increased than normal adult in the temporal parameters. 2. The mean angles of joint pelvic tilt and hip, knee, ankle joint decreased than normal adult at kinematic characteristics on sagittal plane. 3. The mean angles of joint pelvic tilt and hip, knee joint has no difference than normal adult at kinematic characteristics on coronal plane. 4. The mean angles of joint pelvic tilt, hip joint no difference and internal, external rotation in ankle joint significantly decreased than normal adult at kinematic characteristics on transverse plane.

• Physical Therapy Rehabilitation Science
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• v.10 no.4
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• pp.406-413
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• 2021

Objective: The purpose of this study was to investigate effects of taping technique applied to knee instability. Design: Cross sectional study. Methods: Twenty-six participants with knee instabilityparticipated in this study. They were randomly assigned to the Kinesio taping (KT) group (n=13) and the dynamic taping (DT) group (n=13). Both groups applied knee stabilization taping techniques. In order to compare the effects of each taping technique, the change in the landing error scoring system (LESS) and lower extremity joint angle wasrecorded before and after the intervention. Results: Both groups significantly decreased in the change before and after the LESS (p<0.05). At the joint angle of the lower extremities, KT group significantly reduced the valgus angle at the max knee flexion (p<0.05). In DT group knee joint flexion and hip joint flexion angles were significantly increased at foot contact (p<0.05). In max knee flexion, the knee joint flexion angle was significantly increased (p<0.05). In foot contact, max knee flexion, the knee joint valgus angle was significantly increased (p<0.05). DT group showed more significant changes in knee joint flexion angle at foot contact and hip joint flexion angle at max knee flexion. Conclusions: Dynamic taping is a clinically applicable intervention method for lowering the risk of non-contact injury in participants with knee instability and for knee stability during rehabilitation exercises.

• Advances in biomechanics and applications
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• v.1 no.1
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• pp.57-66
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• 2014

The purpose of the study was to investigate the kinematics between the double collar-tie and double underhook Thai Boxing clinching positions. Ten amateur mixed martial arts athletes executed six knee strikes for both clinching positions with their dominant limb directed towards a target. A standard two-dimensional video motion analysis was conducted, and the results showed a statistical significant difference at the hip joint angle and the angular acceleration of the knee and ankle. Within both clinching positions, there was a statistically significant correlation between the hip and knee joint angles, hip and knee angular velocities, and hip angular acceleration. Between both clinching positions, there was a statistically significant correlation at the knee joint angle, knee angular velocity, and hip angular acceleration. This study demonstrates the importance of the hip and knee joint movements in both clinching positions, which implies the applications of strength training and flexibility at these joints for sports performance and injury prevention. It is suggested that future studies analyzing the non-dominant leg are warranted to fully understand the Thai Boxing clinch.

• Physical Therapy Korea
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• v.18 no.3
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• pp.26-37
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• 2011

Although there have been various studies related to the body's movement from a sitting to a standing position (sit-to-stand task), there is limited information on the kinematic changes on the frontal and transverse planes. The purpose of this study was to ascertain how pelvic tilt affects kinematic changes in the frontal and transverse planes in the hip and knee joints during a sit-to-stand task. For this study, 33 healthy participants (13 female) were recruited. Each participant rose from a sitting to a standing posture at his or her preferred speed for each of three different pelvic tilt trials (anterior, posterior, and neutral), and the measured angles were analyzed using a 3-D motion analysis system. A one-way repeated measure analysis of variance was performed with Bonferroni's post hoc test. In addition, an independent t-test was carried out to determine the sex differences in hip and knee joint kinematic changes during the sit-to-stand tasks. The results were as follows: 1) The hip and knee joint angle in the frontal and transverse planes showed a significant difference between the different pelvic tilt postures during sitting in the pre-buttock lift-off phase (pre-LO) (p<.05). Compared to the posterior pelvic tilt posture, the anterior pelvic tilt posture involved significantly greater hip joint adduction and internal rotation, knee joint adduction, and reduced internal rotation of the knee joint. 2) Sex differences were found with significant differences for males in the initial and maximal angles in the frontal plane of the hip and knee joint (p<.05). Females had a significantly smaller initial abduction angle of the hip joint and a significantly greater maximal angle of the hip adduction joint. These results suggest that selecting a sit-to-stand exercise for pelvic tilt posture should be considered to control abnormal movement in the lower extremities.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1515-1517
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• 2008

The purposes of this study were to measure the ranges of motion in knee joint and during continuous passive motion(CPM) treatment and to computationally calculate joint angles at the knee joint dependent on the CPM machine design and its application. Four CPM machines and eleven candidates were recruited for this study. Experimental and numerical studies have been peformed to calculate the range-of-motion of CPM machines. From the experimental measurements, the average range of motions at the knee joint for the CPM machine #1, #2, #3, and #4 were lower than the manufactures suggested values due to improper alignments of the hip and knee joints to the CPM machines. Different design of CPM machine generated different outcomes of the ROM at the knee joints during CPM. The experiments and kinematic simulation in this study could be used to provide useful guidance in the treatment of CPM after joint surgery.

• Korean Journal of Applied Biomechanics
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• v.16 no.4
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• pp.83-94
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• 2006

The purpose of this study is to elucidate how walking speed influences on change of angles of lower extremity and ground reaction force in normal and obese people. One group with normal body weight who were experimented at a standard speed of 1.5m/s and the other obese group were experimented at two different walking speeds (standard speed of 1.5m/s and self-selected speed of 1.3m/s). We calculated angles of lower extremity and ground reaction force during stance phase through video recording and platform force measuring. When the obese group walked at the standard speed, dorsi-flexion angle of ankle got bigger and plantar-flexion angle of ankle got smaller, which were not statistically significant. There was no significant difference of knee joint angles between normal and obese group at the same speed walking but significant post hoc only for the first flexion of knee joint in obese group. $F_z1$ was bigger than $F_z3$ in vertical axis for ground reaction force in both groups at the standard speed walking and the same force value at self-selected speed in obese group. $F_y3$ was always bigger than $F_y1$ in anterior-posterior axis in both groups.

• Journal of the Korean Society of Physical Medicine
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• v.16 no.4
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• pp.1-11
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• 2021

PURPOSE: Lumbosacral orthosis (LSO) is often used to help manage low back pain because it is economical and effective. This study examined the effects of flexible and semirigid LSOs on the lower-limb joint angles in walking in patients with chronic low back pain. METHODS: The effects of the lumbosacral orthosis during gait on the sagittal, frontal, horizontal planes and the change in lower limb angle were examined in fourteen chronic low back pain patients who walked without wearing a LSO, wearing a flexible LSO, and wearing a semirigid LSO in random order for three-dimensional motion analysis. RESULTS: The flexion of the hip and knee joints decreased more significantly during walking with an LSO than without one. The genu valgum angles were reduced in the stance phase more during walking with an LSO than without one. The external rotation of the knee joints in the stance phase increased more during walking with an LSO than without one. CONCLUSION: The angles of the lower-limb joints of patients with chronic low back pain are affected by walking with an LSO, and the effects increased as the LSO stiffened.

• The Journal of Korean Physical Therapy
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• v.16 no.3
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• pp.192-204
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• 2004

The surface electromyographic(sEMG) analyses were knee joint angle during open kinetic chain exercise (OKC) and close kinetic chain exercise (CKC) in vastus medialis (VM), vastus lateralis (VL), and rectus femoralis (RF). Ten subjects with normal , aged 20 to 30(X=27.4, SD=3.23), were randomized Statistical techniques for data analysis were applied paired t-test. The 0.05 level of significane was used as the critical level for rejection of the null hypotheses for the study. And the results were: 1) Both OKC and CKC improved the strength of quadriceps muscle as the knee joint flexion was increased. 2) In OKC, the strength of VM was improved the most at the 30 degree angle. 3) In CKC, the strength of VM was improved the most at the 30 degree angle. 4) The VM/VL ratio was the largest at the 10 and 20 degree angles in OKC and CKC. 5) The VM/VL ratio at 10, 20, and 30 degree angles was significantly different between OKC and CKC (P < 0.05). Base on the results, the OKCE is recommended for the knee joint patients, especially for the patellofemoral pain syndrome patients, during the early phase of rehabilitation. In order to improve strength of the quadriceps, muscle strength training at 30 degree angle is recommended. In order to improve VM/VL ratio, 10 and 20 degree angles are recommended during OKCE and CKCE, respectively. Future researches are warranted comparing electromyographic analysis between OKCE and CKCE in the quadriceps at a certain work lead, and muscle strength performance in the quadriceps at different positions of foot.