• Korean Journal of Applied Biomechanics
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• v.31 no.2
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• pp.113-118
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• 2021

Objective: The purpose of this study was to investigate differences of landing strategy between people with or without chronic ankle instability (CAI) during double-leg drop landing. Method: 34 male adults participated in this study (CAI = 16, Normal = 18). Participants performed double-leg drop landing task on a 30 cm height and 20 cm horizontal distance away from the force plate. Lower Extremities Kinetic and Kinematic data were obtained using 8 motion capture cameras and 2 force plates and loading rate was calculated. Independent samples t-test were used to identify differences between groups. Results: Compared with normal group, CAI group exhibits significantly less hip internal rotation angle (CAI = 1.52±8.12, Normal = 10.63±8.44, p = 0.003), greater knee valgus angle (CAI = -6.78±5.03, Normal = -12.38 ±6.78, p = 0.011), greater ankle eversion moment (CAI = 0.0001±0.02, Normal = -0.03±0.05, p = 0.043), greater loading Rate (CAI = 32.65±15.52, Normal = 18.43±10.87, p = 0.003) on their affected limb during maximum vertical Ground Reaction Force moment. Conclusion: Our results demonstrated that CAI group exhibits compensatory movement to avoid ankle inversion during double-leg drop landing compared with normal group. Further study about how changed kinetic and kinematic affect shock absorption ability and injury risk in participants with CAI is needed.

• Journal of Korean Physical Therapy Science
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• v.29 no.3
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• pp.56-62
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• 2022

Background: The purpose of this study was to investigate the effects of ankle joint immobilization on postural balance during quiet standing. Design: Cross-sectional study Methods: Twenty-seven healthy subject participated in this study. The subjects performed to stand quietly for 30s in eyes open on the platform with three different conditions. The sway length, sway area and sway velocity of center of gravity (COG) displacement and limit of stability (LOS) was measured using the balance platform. Repeated measured ANOVA was used to compare the postural balance parameters depending on three different ankle immobilized conditions. Results: Sway length, sway area and sway velocity of the COG displacement with bilateral ankle immobilized condition was significantly increased compared to those of the other two conditions(p<0.05). All directions of LOS with bilateral ankle immobilized condition were significantly decreased compared to those of the other two conditions. Conclusion: These findings suggest that ankle joint immobilization could be one of the factors that interfere the maintaining of the postural balance in quiet standing.

• Korean Journal of Applied Biomechanics
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• v.32 no.2
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• pp.37-42
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• 2022

Objective: The aim of this study is to analyze the effect of the strength of the ankle support on the walking characteristics and ankle joints when men with flexible flat feet walk. Method: 13 adult male subjects (age: 23.9 ± 2.4 yrs, height: 173.0 ± 5.0 cm, weight: 76.9 ± 13.2 kg, Navicular Drop Test (NDT): 10.2 ± 0.8 mm) participated in this study. Each participant had to walk with the 3 conditions, barefoot, soft arch support and hard arch support, along a walkway while their kinematics was recorded at 100 Hz. Results: Based on the results of this study, it is considered that men with flexible flat feet should use hard arch support rather than bare feet to induce normal arch shape, relieve foot damage caused by excessive ankle joint abnormalities and improve stability. Conclusion: Our results for men with flat flexibility, there was a significant difference in the value of step length when walking was performed using two arch supports with different strengths. The angle of ankle dorsiflexion was significantly increased, and the ankle eversion angle was significantly decreased.

• Journal of Hospice and Palliative Care
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• v.12 no.3
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• pp.139-146
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• 2009

This study was designed to examine the effect of aroma massage therapy on lower extremity edema of terminal cancer patients. Methods: A total of thirty-six terminal cancer patients with lower extremity edema were divided into two groups: the aroma massage group received massage with blending oil which was applied from toes to 10 cm above the knee of the subject for 15 to 20 minutes in each turn, while the control group received sham aroma massage (applied with carrier oil only). The circumferences of the fore-foot, ankle and calf were measured before massage and 30 minutes, 2 hours, and 12 hours after massage. The blood pressure, pulse and body temperature were also measured to find the change of subject's physiologic conditions. Results: There were no significant differences in blood pressure, heart rate, body temperature and lower extremity circumferences between two groups. However, edema at each site was slightly improved in the treatment group after the aroma massage therapy, compared to baseline data (P<0.05). In addition, the reduction of lower extremity circumference was maximal at 2 hours in foot, 30 min in right ankle and 12 hours in right calf after aroma massage therapy (P<0.05). Conclusion: Our results suggest that aroma massage therapy is not effective on the lower extremity edema of terminal cancer patients.

• Journal of Korean Foot and Ankle Society
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• v.19 no.4
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• pp.142-150
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• 2015

Purpose: Restoration of ankle stability through the strengthening exercise of peroneus muscles is considered an important factor for achievement of successful outcomes, in the rehabilitation program following ankle ligament injuries. However, there were few definitive data on normal muscle strength, including eversion power by peroneus muscles. This study was conducted to evaluate the muscle strength of ankle joint measured using an isokinetic dynamometer in normal Koreans. Materials and Methods: Sixty adults (120 ankles) were recruited and divided into three groups (20 in their twenties, 20 in thirties, and 20 in forties). Each group consisted of 10 males and 10 females. The selection criteria were no history of ankle injury and no evidence of instability. The peak torque, total work, and deficit ratio were measured using the Biodex$^{TM}$ (Biodex Medical Systems). Differences in muscle strength by age, gender and dominant versus non-dominant side were analyzed. Results: The peak torque of dorsiflexion was average 31.5 Nm at $30^{\circ}/s$ of angular velocity and 18.8 Nm at $90^{\circ}/s$; average 69.3 Nm ($30^{\circ}/s$) and 42.4 Nm ($90^{\circ}/s$) on plantarflexion; average 19.6 Nm ($30^{\circ}/s$) and 10.8 Nm ($90^{\circ}/s$) on inversion; average 12.9 Nm ($30^{\circ}/s$) and 8.0 Nm ($90^{\circ}/s$) on eversion. The deficit ratio of strength in women was average 61.1% of men on dorsiflexion; average 66.2% on plantarflexion; average 48.5% on inversion; average 55.4% on eversion. The deficit ratio in non-dominant foot was average 88.6% of dominant foot on dorsiflexion; average 90.1% on plantarflexion; average 85.1% on inversion; average 85.6% on eversion. Conclusion: The muscle strength of the ankle joint showed a tendency to weaken with age. There were significant differences in muscle strength by gender and dominancy. Further studies for comparison of patients with ankle instability, a comparison between before and after surgery for instability, the correlation between clinical outcomes and the recovery in muscle strength will be needed.

• Journal of Life Science
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• v.19 no.9
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• pp.1299-1303
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• 2009

The purpose of this study was to analyse the gait characteristics of stroke patients walking on a Zebris system, through quantitative three-dimensional biomechanical analysis. They underwent a continuous rehabilitation training program (RTP). A comparison was made between 3 month and 6 month RTP participants. Their ages were between 60 and 65. The data were analyzed by t-test. The result of comparative analysis of the two groups can be summarized as below. Temporal-spatial data, sagittal plane angular kinematics data, and peak ground reaction force and max pressure data showed that there were no significant differences between the 3 month RTP group and the 6month RTP group (Table 2, Table3, Table 4). It can be suggested that patients with hemiplegia after stroke can improve their walking function through continuous RTP participation.

• Journal of Korean Foot and Ankle Society
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• v.14 no.1
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• pp.41-46
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• 2010

Purpose: Anterior drawer and varus stress test are commonly used for radiologic evaluation of chronic lateral ankle instability. However, there are controversies regarding the method of measurement and the normal value. This study was performed to investigate radiologic normal values in normal Korean adults and to analyze differences by age and gender. Materials and Methods: Sixty Korean adults were recruited and divided in three groups (20 in their twenties, 20 in their thirties, 20 in their forties). There were 10 males and 10 females in each group. The selection criteria were no history of ankle injury and no evidence of instability on physical examination. Radiologic measurement of varus talar tilt and anterior talar translation were performed through anterior and varus stress radiographs using Telos device (150N force). The measurement was repeated twice by three researchers, and intraobserver reproducibility and interobserver reliability were analyzed. The average talar tilt and anterior talar translation were obtained. Results: Talar tilt and anterior talar translation on ankle stress radiographs had good intraobserver reproducibility and interobserver reliability. Talar tilt was average $3.7^{\circ}$ and $5.1^{\circ}$ in male and female of twenties of age, $3.9^{\circ}$ and $4.8^{\circ}$ in their thirties, $3.4^{\circ}$ and $4.5^{\circ}$ in their forties. Anterior talar translation was average 3.5 mm and 4.2 mm in their twenties, 4.1 mm and 3.8 mm in their thirties, 3.6 mm and 4.1 mm in their forties. There was no significant difference in talar tilt and anterior talar translation by age. However, there was significant difference in talar tilt by gender. Conclusion: Normal range of talar tilt angle in Korean adults was below $8.3^{\circ}$, and normal range of anterior talar translation was below 7.6 mm. It seems to be able to serve as a good reference for radiologic evaluation and for treatment of chronic lateral ankle instability.

• Journal of Korean Foot and Ankle Society
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• v.18 no.3
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• pp.108-114
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• 2014

Purpose: Ligament reattachment technique using a suture anchor appears to show satisfactory functional outcomes and mechanical stability compared with conventional bone tunnel technique. This study was prospectively conducted in order to evaluate functional outcomes of modified Brostrom procedures using the suture bridge technique for chronic ankle instability in athletes. Materials and Methods: Twenty eight athletes under 30 years of age were followed for more than two years after undergoing the modified Brostrom procedure using the suture bridge technique. Functional evaluation consisted of the foot and ankle outcome score (FAOS), foot and ankle ability measure (FAAM) score. Range of motion and time to return to exercise were evaluated using a periodic questionnaire. Talar tilt angle and anterior talar translation were measured through stress radiographs for evaluation of mechanical stability. Results: FAOS improved significantly from preoperative mean 59.4 points to 91.4 points (p<0.001). Daily living and sport activity scores of FAAM improved significantly from preoperative mean 50.5, 32.5 points to 94.8, 87.3 points, respectively (p<0.001). Talar tilt angle and anterior talar translation improved significantly from preoperative mean $16.8^{\circ}$, 13.5 mm to $4.2^{\circ}$, 4.1 mm at final follow-up (p<0.001). Times to return to exercise were as follows: mean 10.2 weeks in jogging, 15.4 weeks in spurt running, 13.1 weeks in jumping, 11.5 weeks in walking on uneven ground, 9.1 weeks in standing on one leg, 7.2 weeks in tip-toeing gait, 8.4 weeks in squatting, and 10.6 weeks in descending stairs. Conclusion: Modified Brostrom procedure using the suture bridge technique showed satisfactory functional outcomes for chronic ankle instability in athletes. Optimal indication and cost-effectiveness of the suture bridge technique will be studied in the future.

• Journal of Convergence for Information Technology
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• v.7 no.2
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• pp.91-99
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• 2017

The purpose of this study was to clarify the differences between the K-pop and B-boy dancers'characteristics based on the biomechanical variables through the isolation movement by independent variable t-test using spss 18.0. As a result, first, the CoM composite displacement of the K-pop dancer was larger than that of the B-boy(p<.05) in phase1 and phase2. Second, in phase2 and phase3, the movement speed of CoM was faster in K-pop dancer than in B-boy(p<.05). Third, in phase1, the planar angle between the body and pelvis was greater in the right planar angle of the K-pop dancer, while in the phase2 and phase3, the left planar angle of the B-boy was larger(p<.05). Fourth, the composite hip joint moments of B-boy were larger than those of K-pop in phase1, However, K-pop dancers showed greater moments in phase2, phase3 and phase4, and ankle joint moments in phase3(p<.05). Thus, even with the same isolation, we found that K-pop and B-boy dancers performed differently.

• Journal of the Korean Applied Science and Technology
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• v.38 no.2
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• pp.532-542
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• 2021

The purpose of this study was to investigate the body's strategy through kinematic variables of the lower extremities and ground reaction forces to maintain the club-head speed and ball accuracy despite the three stances during the golf swing. Ten male golfers who official handicap two were participate in the experiment. All subjects performed swing after maintaining the address posture according to stance conditions(square; SS, open: OS, closed: CS). Using a 3D motion analysis system and force plateform, the results were calculated with the 7-iron full swing each stance. In result, there was no difference in center of displacement, and left and right hip and knee joint angle displacement. Left ankle joint was largely plantar-flexed in OS, and right ankle joint was largely performed in CS from the address to the downswing. From address to take-back, right foot had a large left direction and the left foot had a right direction were greater in OS than in CS. Therefore, despite various stances, maintaining the same posture at impact is thought to have a positive effect on club head speed and ball direction.