• Korean Journal of Applied Biomechanics
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• v.33 no.3
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• pp.110-117
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• 2023

Objective: The purpose of this study was to find out kinematic and kinetic differences the lower extremity joint according to the landing type during vertical jump movement after jump landing, and to present an efficient landing method to reduce the incidence of injury in youth players. Method: Total of 24 Youth players under Korean Sport and Olympic Committee, who used either heel contact landing (HCG) or toe contact landing (TCG) participated in this study (HCG (12): CG height: 168.7 ± 9.7 cm, weight: 60.9 ± 11.6 kg, age: 14.1 ± 0.9 yrs., career: 4.3 ± 2.9 yrs., TCG height: 174.8 ± 4.9 cm, weight: 66.9 ± 9.9 kg, age 13.9 ± 0.8 yrs., career: 4.7 ± 2.0 yrs.). Participants were asked to perform jump landing consecutively followed by vertical jump. A 3-dimensional motion analysis with 19 infrared cameras and 2 force plates was performed in this study. To find out the significance between two landing styles independent t-test was performed and significance level was set at .05. Results: HCG showed a significantly higher dorsi flexion, extension and flexion angle at ankle, knee and hip joints, respectively compared with those of TCG (p<.05). Also, HCG revealed reduced RoM at ankle joint while it showed increased RoM at knee joint compared to TCG (p<.05). In addition, HGC showed greater peak force, a loading rate, and impulse than those of TCG (p<.05). Finally, greater planta flexion moment was revealed in TCG compared to HCG at ankle joint. For the knee joint HCG showed extension and flexion moment in E1 and E2, respectively, while TCG showed opposite results. Conclusion: Compared to toe contact landing, the heel contact landing is not expected to have an advantage in terms of absorbing and dispersing the impact of contact with the ground to the joint. If these movements continuously used, performance may deteriorate, including injuries, so it is believed that education on safe landing methods is needed for young athletes whose musculoskeletal growth is not fully mature.

• The Journal of Korean Physical Therapy
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• v.14 no.4
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• pp.172-182
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• 2002

Objectives: We did research in the cause of the Pitchers' injury and their recovery process to make a detailed injury list for the purpose of finding the cause of the Korean professional pitchers' injury and its classification. We drew the conclusion through the results as following. Methods: We posed a question to the 80 pitchers playing in the first team of the eight Korean professional baseball team and analyzed the 62 pieces of question paper except the paper having a mistake. We used SAS/PC statistical package in analyzing the data. Results: In the frequency of the pitchers' shoulder injury in the last three years, the injured of all the players were 61.3$\%$ and the injury free players were 28.7$\%$. The cause of the injury was 45.2$\%$ wrong pitching motion, which was the highest value. For the shape of a pain when injured, the reverberation ache feeling when he is hit in the weight commanded an absolute majority as 19.4$\%$. Those who had muscular pain were 17.7$\%$, which was felt mostly at the pitching motion. The most trouble name of the injured shoulder was bicepstendinitis as 16.1$\%$ while the injury of shoulder joint was the lowest as 1.6$\%$. As the most widely used treatment, 25.8 percent of all the players had taken an electronical thraphy after injury. 14.5 percent of the players who had an injury to the shoulder told that they have an operation and 85 percent of them didn't. As a sort of the operation, a repairing of labrum was 44.4 percent, which is the highest value and the 77.8 percent pitchers are performing a normal pitching through rehabilitation after the operation and 22.2 percent of them are undergoing rehabilitation training. Conclusion: The research have shown that the main cause of the injury, concerning the Korean professional pitchers throwing lots of ball in both matches and practices, is overuse syndrome, bad mechanism, muscle weakness and instability of balance. I think that the role of trainer, physical therapy, and team physician taking charge of the players' injury must learn physical test method by heart exactly to check up the state of the injury definitely at the initial phase. Moreover, when the cause of the injury part after a close examination is discovered, the scientific and good surgery is essential to the rehabilitation success and making a classification of shoulder instability is useful to make a operation plan as well as the players' rehabilitation, treatment.

• Korean Journal of Health Education and Promotion
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• v.18 no.1
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• pp.35-47
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• 2001

As the complexity of the our environment is further complicated by advancements in industry and increase in vehicle traffic flow, the incidents of injury causing accidents are on the rise. Consequently, there is increasing emphasis on the importance of systematic and continual safety education for injury preventive behaviors. This study investigates safety related problems of elementary school students based on the PRECEDE model, proposed by Green et al.(1980 Green), to comprehensively identify the requirements of school safety education. The identified requirements were used to diagnose the current state of elementary school safety education through the analysis of multidimensional factors. A questionnaire survey was conducted on 594 sixth grade students from randomly selected 4 schools in Seoul to examine their injury preventive behaviors and to determine the educational diagnosis variables that affect it. The duration of the survey was 3 weeks starting from April 12, 1999 to May 8, 1999. A summary of the survey results are presented below; 1. Situations in which accidents have occurred were, in their order of frequency, ‘during play or sports activities within the school grounds’ was most frequent at 59.6％, ‘during play on local streets’ at 49.5％, and ‘traffic accidents’ at 41.6％. 2. Categorization of the injury preventive behavior showed that ‘not playing at high traffic flow locations such as streets and construction sites’ had the higher level of observance, while ‘wearing of helmets and joint protection devices during playing’ was least observed. 3. Considering injury preventive behaviors in relation to educational diagnosis variables indicated, for predisposing factors, lower ‘perception to injury accidents’ (p〈0.001) combined with higher ‘concerns for injury accidents’(p〈0.001), ‘practice of preventive behavior’(p〈0.001), and ‘the level of safety knowledge’(p〈0.001) resulted in significantly higher observance of injury preventive behaviors. For enabling factors, higher ‘perceived level of the school safety education’ (p〈0.001) and ‘availability of safety education resources’(p〈0.01) indicated significantly higher observance of injury preventive behaviors. For the reinforcing factor, frequent exposure to ‘safety education brochure’ (p〈0.01) and ‘audio-visual material for safety education’(p〈0.01) combined with more ‘regional safety education’ (p〈0.01), ‘home safety education’ (p〈0.01), ‘school safety education’(p〈0.001), and, ‘parents’ observance of preventive behaviors' (p〈0.001) showed significantly higher observance of injury preventive behaviors. 4. An analysis of the factors that affect injury preventive behaviors showed that the enabling factor ‘awareness of school safety education’ had the highest correlation with injury preventive behaviors followed by factors, in their order of significance, ‘practice of preventive behavior’, ‘perception to injury accidents’, ‘level of safety knowledge’, ‘parents’ observances of preventive behaviors', and ‘concerns for injury accidents.’

• Korean Journal of Applied Biomechanics
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• v.14 no.1
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• pp.133-144
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• 2004

The purpose of this study was to analyze the joint moment on lower extremity during a developpe devant. Data were collected by Kwon3D, KwonGRF program. Two professional modem female dancers were participated in this experiment. Subjects performed a developpe devant in meddle heights. On the axes of X, Y, Z, it was shown that the maximum joint moment was occurred in hip joint. The moments are plotted during developpe devant. The ankle muscles generate a plantar flexion moment and the knee muscles generate a flexion moment and The hip muscles generate a extension moment. So these muscles of joint muscles were known to play a key role in keeping the body balance while doing developpe devant. In addition adduction moment occurred at hip, knee, an ankle in the order of amount, we could assume from this data that him out motion started from the hip joint. There was small active turn out possible below the hip joint. A small amount of extra turn out could be obtained when standing because of flexion between the foot and floor, which could be used to give a passive external rotation force to the whole leg and this could produce a rotation between the knee and foot. This passive external rotation could produce very damaging results. Therefore, lower extremity joint muscles such as hip, knee, and ankle muscle should be trained to keep the body balance and prevent injury during developpe devant performance. And for the safe and perfect turn ort performance, hip joint abduction, the most important external rotating muscle for him out is needed to train and full stretching should be done in advance.

• Journal of muscle and joint health
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• v.3 no.2
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• pp.216-228
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• 1996

This study has purpose to perform leaving the hospital nursing plan during hospital treatment of patient with the knee ligament Injury on the basis of the concerns between the time of leaving the hospital after 2 weeks in hospital and the concerns through practical life after leaving the hospital systematically. This study is also tried to make exercise plan to prevent atrophy of Quardriceps muscle of the thigh caused by the limitation of activities. The subjects of study are 12 people who were in the hospital in affiliation to a university in Seoul, were operated on the knee ligament, and were discharged from the hospital within 2 weeks. Data collection time was for about 4 months from December, 94 to March, 95. Research method was performed 2 times by unorganized open questions. The collection of first data is through direct interview about the concerns before leaving the hospital, and secondary data is through direct interview about the concerns by practical life and experiences after leaving the hospital. The data was categorized by classifying several common elements among similar contents according to data by the situational analysis of Giorgi. The result of this study is as follows : 1) The concerns before leaving the hospital are like that the concerns of recovery possibility, the limitation of activities, the grim realities of life, the lack of confidence about self-nursing, the eyes of the surroundings, the burden to the others, and so on. 2) The concerns after leaving the hospital are like that the demands of the inconvenience by the limitation of self-nursing, the support about self-nursing by the difficulties of performing treatment order, the support of physical activities limitation by physical tiredness and the limitation of social activities, the support of information by the necessities of education in using crutches before leaving the hospital and continuing informational needs, psychological and mental support of normal physical recovery by the worries of physical recovery and physical change, and social support by thankfulness for his family and relatives. I suggest to make more systematic leaving the hospital nursing plan and exercise education plan for nursing plan after leaving the hospital of the patients with the knee ligament injury on the basis of this content.

• Journal of Oral Medicine and Pain
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• v.42 no.4
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• pp.109-115
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• 2017

Purpose: This study analyzed the effects of digastric muscle injury on mandibular growth in young rats. Methods: Fourteen 4-week-old Wistar rats were divided into 3 groups; experimental group A (n=6) with unilateral (right) shortening of the posterior digastric muscle, experimental group B (n=6) with bilateral shortening of the posterior digastric muscles, and control group C (n=2) who underwent a sham operation. Eight weeks after the operation all animals were sacrificed and the outcomes were compared using body weight evaluation, mensurations on lateral radiograph of hemimandibles and histological evaluation. Results: There was no significant difference between groups A and B in body weight gain. Comparison of the mean values of hemimandible distance on radiograph was performed. The difference in group mean value of mandible-related distances was analyzed using the Wilcoxon test (rank sum test) and a comparison of the homonymous distances of group A and B was performed using the Mann-Whitney test. There were differences between sides in mandibular length in group B and mandibular ramus height and transverse width of the condyle in group A (all, p<0.05). There were differences in condylar height and mandibular length on the left side between groups A and B (p<0.05). Histologic examination of temporomandibular joint showed similar findings in all specimens. Conclusions: Injury of the posterior belly of the digastric muscle during the rat growth period induced shortening of mandibular ramus height and transverse width of the condyle. It can be inferred that trauma to the posterior belly of the digastric muscle affects horizontal and vertical growth of the mandible.

• Korean Journal of Applied Biomechanics
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• v.20 no.1
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• pp.67-73
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• 2010

The purpose of this study was to compare the differences in kinematic and kinetic parameters of the ankle and knee joint according to three landing direction(central, left, right). Fifteen collegiate male athletes(age: $22.7{\pm}3.5$ years, height: $174.9{\pm}7.1\;cm$, weight: $69.4{\pm}6.7\;kg$) with the right leg as dominant were chosen. The subjects performed series of drop landings in three directions. In terms of the three different landing directions, plantar flexion was the greatest during the central drop landings. For each initial contact of the landing direction, plantar flexion of the ankle was greatest at the central drop landing, inversion of the ankle was greatest at the right landing and valgus of the knee was greatest at the left drop landing. Regarding the peak force, the greatest was at the 1st peak force during the central drop landing. For the time-span of the 2nd peak force and the 2-1 peak force, both right sides resulted as the greatest. Therefore, with the appropriate training in landing techniques and developing neuromuscular training for proprioception by taking the injury mechanisms on ankle and knee during drop landings into account, it will assist in preventing such injuries.

• Journal of Korean Foot and Ankle Society
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• v.21 no.1
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• pp.21-26
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• 2017

Purpose: To evaluate the clinical outcome of an operation with early rehabilitation from ankle fracture in accordance with the injury type. Materials and Methods: A total of 136 patients (70 males and 66 females) who underwent surgery and early rehabilitation for ankle fractures between December 2008 and December 2013 were retrospectively reviewed. The average age was 47.9 years, with a range of 18~79 years. The mean follow-up period was 28.7 months, with a range of 24~102 months. All patients were classified in accordance with the Lauge Hansen classification and anatomic fracture site. Moreover, the presence of ligament injuries were documented. A short-leg cast was applied postoperatively for two weeks; thereafter, patients began the range-of-motion exercises after cast removal. Full weightbearing was allowed at 2 weeks postoperatively. Each patient was assessed radiologically and clinically based on the OlerudMolander score, visual analogue scale (VAS) for pain, joint stiffness, and capability of single heel raising. Results: Seventeen patients (12.5%) complained of postoperative pain (VAS score 1~3), and the incidence was higher in patients with trimalleolar fractures or associated ligament injuries. Twenty-three patients (16.9%) complained of postoperative ankle stiffness. The mean Olerud-Molander score was 75.4/80 (range, 55~80). Olerud-Molander scores were lower in patients with ligament injuries than in those with fracture alone. There was no nonunion or fracture displacement even after early weightbearing walking. Conclusion: In this retrospective series, early rehabilitation after surgical restoration of ankle mortise by anatomical reduction and stabilization was shown to be successful. Earlier motion exercise and weightbearing walking can minimize fracture complications like joint stiffness or weakness in ankle fracture.

• Physical Therapy Korea
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• v.12 no.1
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• pp.28-35
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• 2005

The purpose of this study was to determine whether gender differences existed in knee valgus kinematics in college students when performing a vertical drop landing. The hypothesis of this study was that females would demonstrate greater knee valgus motion. These differences in knee valgus motion may be indicative of decreased dynamic knee joint control in females. This study compared the initial knee valgus angle and maximum knee valgus angle at the instant of impact on vertical drop landings between healthy men and women. In this study, 60 participants (30 males, 30 females) dropped from a height of 43 cm. A digital camera and two-dimensional video motion analysis software were used to analyze the kinematic data. There was significant difference in the mean knee valgus angle at initial contact landing between the two groups (Mean=$7.88^{\circ}$, SD=$4.24^{\circ}$ in males, Mean=$12.93^{\circ}$, SD=$2.89^{\circ}$ in females). The range of knee valgus angle on landing (Mean=$3.25^{\circ}$, SD=$5.72^{\circ}$ in males, Mean=$11.44^{\circ}$, SD=$6.39^{\circ}$ in females) was differed significantly (p<.05). The maximal angle of knee valgus on landing (Mean=$10.91^{\circ}$, SD=$6.89^{\circ}$ in males, Mean=$24.25^{\circ}$, SD=$6.38^{\circ}$ in females) was also differed significantly (p<.05). The females landed with a larger range of knee valgus motion than the males and this might have increased the likelihood of a knee injury. The absence of dynamic knee joint stability may be responsible for increased rates of knee injury in females. No method for accurate and practical screening and identification of athletes at increased risk of ACL injury is currently available to target those individuals that would benefit from neuromuscular training before sports participation.

• Journal of Korean Foot and Ankle Society
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• v.17 no.3
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• pp.182-188
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• 2013

Purpose: We evaluate clinical manifestations and radiologic features of ankle fracture & dislocation, as well as the usefulness of computed tomography on posterior ankle fracture & dislocation to study factors contributing to ankle fracture & dislocation. Material and Methods: Ankle dislocation was defined as the center of talar body being translated over the cortex of tibia on AP or lateral view on simple X-ray. Surgical treatments of 30 patients from January 2007 to March 2012 were categorized according to the injury mechanism, the direction of dislocation and fracture site. Joint involvement of posterior malleoalr fracture was evaluated through simple x-ray and computed tomography. We treated surgically if posterior malleolus fracture involves more than 25% of dital tibial articular surface. Thereafter, clinical outcomes were identified through radiographs and by using the AOFAS score. Results: The mean age was 42(13-78) years old, and slip down was the most common injury mechanism (13 cases). Car accident (6 cases) and fall accident (4 cases) were the next frequently found injury mechanisms. As for the types of ankle fracture, posterior fracture and dislocation (21 cases, 43.3%) was most commonly found. Out of these 21 cases, 15 cases involved trimalleolar fracture, and 19 cases were associated with posterior malleolar fracture. Danis-weber type B and C patients were 11 cases and 10 cases respectively. Articular involvement of posterior malleolar fracture turned out to be average 27.9%(5.1%~49.1%) on simple x-ray. The rate was evaluated as average 31.7%(12.6%~55.3%) on computed tomography which was conducted 15 times, and led us to more meaningful data. Conclusion: Anterolateral fracture and dislocation often accompanied open dislocation. Posterior fracture dislocation was most commonly found. Posterior malleolus was an important factor that ensures posterior stability of the ankle joint. Computed tomograph is useful to evaluate the articular involvement of posterior malleolar fracture.