• Journal of Korean Foot and Ankle Society
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• v.8 no.2
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• pp.131-137
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• 2004

Purpose: We evaluated the results of various surgical treatments for hallux valgus with and without attempting to correct sesamoid subluxation. Materials and Methods: Thirty-one cases in 26 patients were involved in this study: Group I (15 cases) - surgery performed only to correct the hallux valgus angle (HVA) and the first-second intermetatarsal angle (IMA) in AP view; Group II (16 cases) - surgery performed to correct HVA and IMA and also to reduce the subluxation of sesamoid. The degree of sesamoid subluxation was measured from a pre- and intraoperative sesamoid tangential views. For both groups, we analysed the status of the sesamoid in pre- and postoperative radiographs and performed clinical evaluation using the Mayo clinic forefoot scoring system. Results: The average amount of correction during postoperative period and loss of correction at last follow-up in the sesamoid tangential view were as follows: soft tissue procedures (5 cases) - group I: grade $1.0{\pm}0.4/1.5{\pm}0.3$ and group II: grade $2.0{\pm}0.9/0.5{\pm}0.08$; chevron osteotomy (12 cases) - group I: grade $1.0{\pm}0.5/1.2{\pm}0.3$ and group II: grade $2.2{\pm}0.7/0.9{\pm}0.2$; proximal metatarsal osteotomy (14 cases) - group I: grade $4.0{\pm}0.4/1{\pm}0.2$ and group II: grade $4.7{\pm}1.1/0.8{\pm}0.1$. In clinical evaluation, more than 93% of the feet had a good result in both groups. The analysis of these data for each treatment type did not show any statistically significant differences between groups I and II. Conclusion: The radiologic and clinical results did not validate our attempts to reduce the sesamoid during surgery.

• Korean Journal of Applied Biomechanics
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• v.16 no.3
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• pp.43-51
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• 2006

The purpose of this study was to analyze kinematic variables during turing back kick motion of Taekwondo. The subjects of this study were the 4 skilled and 4 unskilled of male university player in respectively. The experiment of this study was used two 16mm high speed cameras and its speed 125 frames/s. Analysis of this data was three dimensional cinematography using KWON3D program package. The results were as following; 1. In the elapsed time, there was no significance difference statically between a skilled and unskilled group. But skilled group was more fast during the motion of I phase. And unskilled group was more fast during the motion of II phase so called force production section, which had an influence on Diechagi's velocity. 2. In the center of gravity of human body, the changing of it was $1.10{\pm}0.04m$, $1.12{\pm}0.03m$ of LFM(left foot movement) and $1.36{\pm}0.08m$, $1.39{\pm}0.09m$ of RKF(right knee flection), and $1.44{\pm}0.08m$, $1.42{\pm}0.09m$ of RFI(right foot impact). There was no significance difference statically between the two groups. 3. The velocity of heel on impact was 1.13m/s in the skilled group and 1.23m/s in the unskilled group, when each angle of knee was $110.4{\pm}10.9deg/s$, $114.8{\pm}28.4deg/s$. The maximum velocity of each performance was reached before the RKF, and the velocity and angle at impact along by two groups did not show any significant difference statically. 4. In the angular velocity of just RKF of lower leg, there was significance difference statically between the two groups(p<.05).

• Journal of Korean Foot and Ankle Society
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• v.9 no.1
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• pp.1-8
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• 2005

Purpose: We compared the bony arrangements of the forefoot in 2 different years, 1982 and 2004, to determine any changes with time period of 22 years. Materials and Methods: The radiographs of 200 normal Korean adults, 100 male and 100 female volunteers, were evaluated both in 1982 and 2004. The radiographic results were evaluated with as follows; hallux valgus angle (HVA), intermetatarsal angle (IMA), morphology of metatarsal head and relative anterior protrusion of the metatarsals and the phalanges. The mean ages were 38 years (23-52years) in 1982, and 37 years (24-50years) in 2004. Results: The mean of HVA decreased from 15.6 degrees in 1982 to 14.3 degrees in 2004 (p=0.047), and the mean of IMA increased from 8.0 degrees in 1982 to 9.4 degrees in 2004 (p=0.031). The morphology of metatarsal head and relative anterior protrusion of the metatarsals and the phalanges were not different between the two study years. Conclusion: Comparing with those of 1982 measurements, we found an increase of IMA and a decrease of HVA. A prospective study may be needed to illuminate course of the changes.

• Korean Journal of Applied Biomechanics
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• v.30 no.3
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• pp.255-264
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• 2020

Objective: The purpose of this study is to develop new balance evaluation index that can discriminate fall risk factors and provide effective interventions for healthy elderly. In order to conduct this study, the balance assessment tools (TUG, mCTSIB, OLST, FRT and BBS) currently used in clinic were re-evaluated using biomechanical analysis. Method: The participants were healthy elderly people over 65 years old, n=26, age: 69.31±3.13 years; height: 154.00±4.12 cm, body weight: 56.13±6.04 kg. The variables are length of CoM-BoS, length of CoP-BoS, range of CoP, mean distance of CoP, mean frequency of CoP, root mean square of CoP, joint angle, ASM (%SL), CoP-CoM angle. Results: As a result of this study, the following items were included in the list of new balance evaluation index for the healthy elderly, showing differences in the biomechanical evaluation based on the clinical evaluation (Inclusion list: TUG, OLST, 8th assessment item of BBS (reaching forward with outstretched arm), 11th item (turning 360 degrees), 13th item (standing with one foot in front), 14th item (standing on one foot)). Conclusion: Based on the results, the new balance evaluation index for the healthy elderly determined through this study can be used to prevent the fall by evaluating the balance ability in various situations that can be experienced in the normal daily life of the healthy elderly.

• Journal of Korean Foot and Ankle Society
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• v.7 no.1
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• pp.109-114
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• 2003

Purpose: The purpose of this study is to evaluate the effectiveness and indications of the modified Essex-Lopresti reduction in calcaneal fractures. Materials and Methods: We reviewed retrospectively 41 cases of displaced intraarticular calcaneal fractures. The fracture was reduced with Essex-Lopresti technique with modification in compression of the lateral wall with the specially designed compression device instead of the operator's hands. We evaluated the results of treatment by AOFAS scale and the radiographic parameters including the Bohler's angle, calcaneal width, calcaneofibular distance and the congruency of the posterior facet. Results: Boler's angle was restored from 11 to 29.6 degrees on average, heel width was reduced to 112% of contralateral value, the calcaneofibular gap was restored up to 87.9% of contralateral side, and the articular surface of the posterior facet was restored less than 2 mm of step off and less than 2 mm of gap. AOFAS scale averaged 87 points. The quality of reduction was best in Sander's type II fractures. Small sized fragments in type III fractures could not be reduced. The results were better when the reductions were performed within 24 hours of injury. Conclusion: The modified Essex-Lopresti reduction was less invasive, easy to perform, and the results of treatment were similar to those of open reduction; it seemed to be a reasonable alternative for the selected intraarticular calcaneal fractures.

• Journal of Biomedical Engineering Research
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• v.24 no.3
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• pp.209-215
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• 2003

The goal of this study was to investigate the relationship between kinematic and kinetic characteristics of foot joints resisting ground reaction force. Passive elastic joint moment and angular displacement were obtained from the experiment using 3 cameras and force plate. The relationship between joint angle and moment was mathematically modeled by using least square method. The ranges of motion of joints ranged from 5$^{\circ}$ to 7$^{\circ}$ except metatarsophalangeal joint. In the study, we presented simple mathematical models that could relate joint angle and plantar pressure. From this model, we can got the kinematic data of joints which is not available from conventional motion analysis. Furthermore, the model can be used not only for biomechanical model which simulates gait but also for clinical evaluation.

• Journal of Korean Foot and Ankle Society
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• v.7 no.2
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• pp.174-178
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• 2003

Purpose: The purpose of this study was to evaluate the radiographic results and complications after the proximal dome osteotomy for hallux valgus. Material and Methods: 127 cases of clinically moderate to severe hallux valgus from October 1994 to September 1997 were included in this study. All had been surgically corrected with proximal dome osteotomy, bunionectomy, and distal soft tissue release. We compared the hallux valgus angle(HVA) and intermetatarsal angle(IMA) at preoperative, postoperative 3 weeks, postoperative 6 weeks, and postoperative 3 months. Also we reviewed the postoperative com plications. Result: The HVA averaged $34.1^{\circ}$ at preoperative, $4.3^{\circ}$ at 3 weeks after operation, $8.1^{\circ}$ at 6 weeks after operation, and $10.2^{\circ}$ at 3 months after operation. The lMA averaged $14.6^{\circ}$ at preoperative, $5.1^{\circ}$ at 3 weeks after operation, $5.6^{\circ}$ at 6 weeks after operation, and $7.3^{\circ}$ at 3 months after operation. We experienced 7 cases of malunion, 5 cases of limitation of motin at the first metatarso-phalangeal joint, 3 cases of hallux varus deformity, 2 cases of delayed union. Conclusion: Proximal dome osteotomy for moderate to severe hallux valgus deformity was considered as one of the effective treatment methods. And we try to avoid limitation of motion at the first metatarso-phalangeal joint after operation.

• Journal of Korean Foot and Ankle Society
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• v.17 no.4
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• pp.302-308
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• 2013

Purpose: To present clinical results of proximal first metatarsal opening wedge osteotomy and low profile plate fixation in hallux valgus deformity. Materials and Methods: Thirty-two patients (39 feet) underwent surgery for hallux valgus deformity. Fourteen patients (18 feet; Group A) underwent proximal first metatarsal opening wedge osteotomy fixed with low profile titanium plate ($Arthrex^{(R)}$), and 18 patients (21 feet; Group B) underwent proximal chevron osteotomy with two K-wires. Improvement in hallux valgus angle (HVA), 1, 2 intermetatarsal angle (IMA), range of motion of 1st metatarsophalangeal joint, VAS score, and the length of first metatarsal on weight-bearing radiograph were evaluated preoperatively and at final follow-up. Results: HVA improved from $36.2{\pm}6.6$ degrees to $11.7{\pm}5.1$ degrees, and 1, 2 IMA improved from $15.7{\pm}2.6$ degrees to $7.2{\pm}1.9$ degrees. VAS score improved from $7.2{\pm}1.2$ to $1.4{\pm}0.9$. There were no significant differences clinically and radiologically. Conclusion: Proximal first metatarsal opening wedge osteotomy with stable fixation using low profile plate may be an effective surgical option for correction of hallux valgus deformity.

• Journal of Korean Foot and Ankle Society
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• v.17 no.4
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• pp.272-276
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• 2013

Purpose: Recurrence is one of the most common complications after primary correction for hallux valgus deformities. The purpose of this study was to evaluate the usefulness of Scarf osteotomy with axial decompression in the treatment of recurrent hallux valgus. Materials and Methods: From April 2006 to April 2011, 14 cases (12 patients) of recurrent hallux valgus were managed with shortening Scarf osteotomy. Preoperative and postoperative radiographs were reviewed for the measurement of the hallux valgus angle (HVA), intermetatarsal angle (IMA), and the amount of the $1^{st}$ metatarsal shortening. Clinical outcomes including the visual analogue scale (VAS), the AOFAS score, and the range of motion [ROM] of the 1st metatarsophalangeal (MTP) joint were evaluated. Results: The mean HVA decreased from 27.9 degrees to 5.2 and the mean IMA decreased from 12.9 to 3.4. The mean VAS improved from 5.3 to 0.3 and the mean AOFAS score improved from 41 to 90. The mean amount of the 1st metatarsal shortening was 3.4 mm (2-5). The mean ROM of the $1^{st}$ MTP joint improved from 22 degrees (15-35) to 68 (55-75). Conclusion: Scarf osteotomy associated with axial decompression can be a useful revision procedure for the treatment of recurrent hallux valgus deformity.

• Korean Journal of Applied Biomechanics
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• v.15 no.3
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• pp.1-7
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• 2005

Excessive pronation and impact force during running are related to various running injuries. To prevent these injuries, three type of running shoes are used, such as cushioning, stability, and motion control. Although there were may studies about the effect of midsole hardness on impact force, no study to investigate biomechanical effect of motion control running shoes. The purpose of this study was to determine biomechanical difference between cushioning and motion control shoes during treadmill running. Specifically, plantar and rearfoot motion, impact force and loading rate, and insole pressure distribution were quantified and compared. Twenty male healthy runners experienced at treadmill running participated in this study. When they ran on treadmill at 3.83 m/s. Kinematic data were collected using a Motion Analysis eight video camera system at 240 Hz. Impact force and pressure distribution data under the heel of right foot were collected with a Pedar pressure insole system with 26 sensors at 360 Hz. Mean value of ten consecutive steps was calculated for kinematics and kinetics. A dependent paired t-test was used to compare the running shoes effect (p=0.05). For most kinematics, motion control running shoes reduced the range of rearfoot motion compared to cushioning shoes. Runners wearing motion control shoe showed less eversion angle during standing less inversion angle at heel strike, and slower eversion velocity. For kinetics, cushioning shoes has the effect to reduce impact on foot obviously. Runners wearing cushioning shoes showed less impact force and loading rate, and less peak insole pressure. For both shoes, there was greater load on the medial part of heel compared to lateral part. For pressure distribution, runners with cushioning shoes showed lower, especially on the medial heel.