• Korean Journal of Applied Biomechanics
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• v.19 no.4
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• pp.647-653
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• 2009

The purpose of this study was to investigate the differences between female and male ballet dancers in anterior cruciate ligament injury risk factors during the box drop landing task. Nine female and nine male collegiate ballet dancers participated in this study. Kinematic and ground reaction data were collected and combined with inverse dynamics to estimate the knee extensor and abductor moment. EMG data from the biceps femoris and rectus femoris were used to estimate the ratio of quadriceps-hamstrings muscle activity. No gender differences in anterior cruciate ligament injury risk factors were found during the box drop landing task. A significant relationship was found between female and male ballet dancers in the knee flexion angle.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.11
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• pp.1628-1633
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• 2017

The purpose of this study was to identify the difference and correlation in elbow joint maximal flexion strength according to measurement methods and characteristics of muscular contraction, and to develop the predictive equation of elbow joint maximal flexion strength for the optimal exercise intensity setting and accurate measurement. Subjects were 30 male university students. Elbow joint maximal flexion strength of isokinetic contraction, isometric contraction at $75^{\circ}$ elbow joint flexion position, isotonic concentric 1RM, manual muscle strength (MMT) were measured with isokinetic dynamometer, dumbbell, and manual muscle tester. Pearson's r, linear regression equation, and multiple regression equation between variables were calculated. As a result, the highest value was isometric contraction. The second highest value was MMT. The third highest value was isokinetic contraction. 1RM was the lowest. Predictive equations of elbow joint maximal flexion strength between isometric and isokinetic contraction, between isometric contraction and 1RM, among isometric contraction, 1RM, and body weight were developed. In conclusion, 1RM and isokinetic elbow joint maximal flexion strength could be seemed to underestimate the practical elbow joint maximal flexion strength. And it is suggested that the developed predictive equations in this study should be useful in criteria- and goal-setting for resistant exercise and sports rehabilitation after elbow joint injury.

• Journal of Korean Physical Therapy Science
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• v.15 no.3
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• pp.19-29
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• 2008

Background : Ankle inversion sprains are one of the most common injuries in sports and activities of daily living that mostly concern physically active individuals. In most researches, proprioceptive deficit, muscle weakness and/or absent coordination have been regarded as a contributing factors. Despite the high incidence of ankle sprain and instability, therapeutic approaches to properly manage the symptoms have rarely been investigated. This study aimed to identify the effect of proprioceptive exercise program that is easy to integrate in normal training program. Methods : Subjects were randomly allocated to control group and experimental group consisting of 11 and 10 patients, respectively. The conservative treatment for the control group consisted of hot packs, ultrasound and TENS. In addition, the experimental group performed 7 exercises to enhance proprioceptive function of ankle joint. The therapeutic intervention of the controland experimental groups was performed a total of 20 exercise sessions, averaging 50 hour each, 5 times per week for 4 weeks. To compare the two groups, the level of ankle disability was assessed by using the ankle injury score scale in pre- and post-treatment. Results : On assessment of post-treatment, there were statistically significant differences in the scores of all sub-items, except for ankle laxity and range of motion, and the total score of ankle injury score scale between the two groups(p<0.05). In comparison between pre- and post-treatments, the significant difference in the scores of all sub-items and total score didn't appear for the control group, while the scores of most sub-items and total score of the experimental group were shown the statistically significant difference(p<0.05). Conclusion : The findings suggest that the proprioceptive exercise program is more effective for relieving ankle disability than conservative treatment therefore, the program to improve proprioceptive function should be recommended for prevention and rehabilitation of recurrent ankle inversion injuries.

• Journal of Acupuncture Research
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• v.30 no.1
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• pp.35-41
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• 2013

Objectives : This study aimed to perform descriptive analysis on demographic characteristics and symptom distribution of 199 marathon participants in Pusan, Korea. Methods : Brief medical charts of 199 marathon participants in 11 marathon rallies who had visited the emergency medical support team of Korean Medicine Hospital, Pusan National University were collected. Participants' demographic and clinical characteristics were descriptively analyzed. Results : More than two third of participants who have visited the support team was male(71.9 %) and their mean age was 44.0(years). The main intervention was manual acupuncture with vigorous stimulation techniques. Most of treated symptoms were lower extremity pain(77.0 %). Knee pain was the most frequently recorded symptoms, following the ankle pain. No information on the safety of acupuncture treatments were reported in the records. Conclusions : Symptom distribution of marathon participants who have visited the emergency medical support team of Korean Medicine Hospital was similar to previous literatures of acute injuries of marathon athletes and runners. The role of acupuncture for emergency support care of acute injuries in marathon participants should be further explored in well-designed clinical studies.

• Clinics in Shoulder and Elbow
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• v.19 no.1
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• pp.15-19
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• 2016

Background: To investigate how many rookie pitchers suffered from injuries while playing in the amateur league without guidelines for prevention of excessive pitching, we analyzed their amateur pitching patterns based on the pitch count, use of breaking balls, and pitches during winter camp. Methods: Forty-one rookie pitchers who graduated from high school or university in 2013 and joined professional baseball teams. Participants were interviewed by a trainer using our questionnaire. Injury inclusion criteria were 1) history of shoulder surgery, 2) history of elbow surgery, 3) shoulder pain requiring treatment, and 4) elbow pain requiring treatment. Results: Mean number of pitches per game and warm-up pitches for practice was 84.5 pitches (range, 15 to 130 pitches) and 16.4 pitches (range, 2 to 210 pitches), respectively. Mean number of pitches during the last year was 906.9 (range, 80 to 2,000). Mean number of maximal pitches was 127 pitches (range, 50 to 210 pitches). Fourteen pitchers had pitched over 150 pitches. Twenty-seven pitchers (65.9%) had pitched in spite of enduring pain. During winter training (mean 1.8 months), mean number of pitches per day was 162.5 pitches, and 20 pitchers (48.8%) had practiced pitching excessively despite the cold weather. Twenty-six rookies (63.4%) had shoulder pain or history of shoulder surgery, and 31 pitchers (75.6%) had elbow pain or history of elbow surgery. Only four participants (9.8%) did not have pain and history of surgery. Conclusions: For young baseball pitchers, guidelines for prevention of excessive pitching and for regulating the winter training program may be needed.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.47 no.5
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• pp.365-372
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• 2021

Objectives: Mandibular fractures vary significantly with respect to epidemiological and demographic parameters among populations. To date, no study has evaluated these aspects of mandibular fractures in Nuh, Mewat, Haryana, India. To retrospectively analyze the incidence, age and sex distributions, etiology, anatomic distribution, occlusal status, treatment modality provided, and their correlation in patients who suffered isolated mandibular fractures. Materials and Methods: The records of maxillofacial injury patients who reported to the Department of Dentistry, SHKM Government Medical College from January 2013 to December 2019, were retrieved from our database, and necessary information was collected. The data collected were analyzed statistically using IBM SPSS ver. 21. Results: Totals of 146 patients and 211 fractures were analyzed. There were 127 males and 19 females with an age range of 3-70 years (mean age, 26 years). Road traffic accident (RTA) was the most common cause of fracture (64.4%), followed by fall (19.9%), assault (15.1%), and sports injury (0.7%). Of all patients, 42.5% had bilateral fractures, 31.5% had left side fracture, 21.2% had right side fracture, 3.4% sustained midline symphyseal fracture, and 1.4% had symphyseal fracture along one side of the mandible. Site distribution was as follows: parasymphysis (34.6%), angle (23.7%), condyle (20.4%), body (12.8%), symphysis (4.3%), ramus 2.4%, and dentoalveolar 1.9%. The most common facture combination was angle with parasymphysis (17.8%). Occlusion was disrupted in 69.2% patients. Closed reduction was the predominant treatment modality. Conclusion: The data obtained from retrospective analyses of maxillofacial trauma increase the understanding of variables and their outcomes among populations. The results of the present study are comparable to those of the literature in some aspects and different in others.

• Korean Journal of Applied Biomechanics
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• v.31 no.3
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• pp.155-161
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• 2021

Objective: There is a lack of studies using the 3D-2D image registration techniques on the mechanism of a shoulder injury for ice hockey players. This study aimed to analyze in vivo 3D glenohumeral joint arthrokinematics in collegiate ice hockey athletes and compare shoulder scaption with or without a hockey stick using the 3D-2D image registration technique. Method: We recruited 12 male elite ice hockey players (age, 19.88 ± 0.65 years). For arthrokinematic analysis of the common shoulder abduction movements of the injury pathogenesis of ice hockey players, participants abducted their dominant arm along the scapular plane and then grabbed a stick using the same motion under C-arm fluoroscopy with 16 frames per second. Computed tomography (CT) scans of the shoulder complex were obtained with a 0.6-mm slice pitch. Data from the humerus translation distances, scapula upward rotation, anterior-posterior tilt, internal to external rotation angles, and scapulohumeral rhythm (SHR) ratio on glenohumeral (GH) joint kinematics were outputted using a MATLAB customized code. Results: The humeral translation in the stick hand compared to the bare hand moved more anterior and more superior until the abduction angle reached 40°. When the GH joint in the stick hand was at the maximal abduction of the scapula, the scapula was externally rotated 2~5° relative to 0°. The SHR ratio relative to the abduction along the scapular plane at 40° indicated a statistically significant difference between the two groups (p < 0.05). Conclusion: With arm loading with the stick, the humeral and scapular kinematics showed a significant correlation in the initial section of the SHR. Although these correlations might be difficult in clinical settings, ice hockey athletes can lead to the movement difference of the scapulohumeral joints with inherent instability.

• Archives of Plastic Surgery
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• v.46 no.3
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• pp.198-203
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• 2019

Background Professional affiliation between medical centers and professional sports teams can be mutually beneficial in the provision of healthcare and marketing strategy. Anecdotal evidence suggests a link between trauma volume and sporting events; however, there is limited data. This study aims to characterize the incidence of operative hand and facial trauma during professional baseball home games. Methods A retrospective review of surgical cases for traumatic hand or facial injuries at a level 1 center between 1999 and 2012 was performed. Demographic information including date of injury, admission status, and operative repair were collected. Patients were grouped based on whether their trauma occurred on the date of a home game. Results Operative hand and facial trauma occurred at a rate of 33.4 injuries per 100 days with home games, compared to 22.2 injuries per 100 days (incidence rate ratios, 1.50; 95% confidence interval, 1.34-1.69). When home games were played, patients were more likely to present as a result of motorcycle accidents (3.1% vs. 1.5%; P=0.04) or bicycle accidents (5.0% vs. 2.6%; P=0.01). Other mechanisms of trauma were not statistically different. There was an increase incidence of injuries during home games in August; weekly variability showed an increased incidence during the weekends. Conclusions There was an increased rate of operative hand and facial injuries on dates with professional home games. The incidence of injuries during home games was higher in the late summer and on the weekends. Further analysis may allow improved resource allocation and strategies for injury prevention and treatment.

• Journal of Sport and Applied Science
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• v.7 no.2
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• pp.1-12
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• 2023

Purpose: The purpose of this study was to investigate the possibility of modified swing to prevent shoulder injury by analyzing differences in the muscle activation patterns of upper limb by the swing method in wheelchair badminton players. Research design, data, and methodology: 10 wheelchair badminton players participated in the experiment as subjects and performed 10 high clears and 10 smashes in both traditional and modified swing methods toward a shuttlecock hung at the height of racket impact point. For each trial, activation patterns of biceps brachii, triceps brachii, anterior deltoid, and posterior deltoid were measured from the upper limb participating in the swing from which the duration, peak, and root mean square (RMS) of electromyography (EMG) activities from swing initiation to shuttle impact were calculated. The maximum swing velocity of the smash and the distance of the high clear were also measured with both methods to compare differences in the swing velocity and shuttle hit distance. Results: Differences in the EMG peak and RMS of the anterior deltoid by swing methods were shown to differ by the skill type, being higher in the traditional swing method than the modified during only the high clear. The EMG peak and RMS, and the duration of the posterior deltoid were higher and longer with the traditional swing method than the modified during both the smash and high clear. The intensities of the biceps brachii and triceps brachii activities measured during the smash and high clear were higher in the traditional swing method than the modified, and the biceps brachii and triceps activity durations during the high clear were shorter in the modified swing method than the traditional. The maximum swing velocity of the smash was faster with the traditional swing method than the modified, while the distance of the high clear did not differ significantly. Conclusions: These results suggest that the modified swing can be an effective performance method for preventing shoulder injuries without undue loss of impact power in wheelchair badminton players by reducing excessive loads imposed on the shoulder and allowing the optimal use of the elbow extension.

• Journal of Korean Orthopaedic Sports Medicine
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• v.9 no.1
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• pp.48-57
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• 2010

Purpose: To compare the incidence and risk factors for osteoarthritis after anterior cruciate ligament (ACL) reconstruction between two groups using bone-patellar tendon-bone (BPTB) and hamstring tendon (HT) autograft. Materials and Methods: 53 cases of ACL reconstruction using patellar tendon and 40 cases using hamstring tendon were followed up at least 8 years. Radiographic evaluation was done according to the Kellgren and Lawrence's classification. Clinical functional testing (Lysholm Knee Scores, the Tegner activity scores) and laxity testing (Lachman, pivot shift tests), and the instrumented laxity testing with $Telos^{(R)}$ were all examined in relation to the development of osteoarthritis. Results: Radiographic osteoarthritic changes were detected in 24 patients (45.3%) in BPTB group and 14 patients (35.0%) in HT group. Accompanying meniscal injury (BPTB p<0.001; HT p=0.091), intervals from the injury to reconstruction of > 12 months (BPTB p=0.037; HT p=0.021), and patient's age at reconstruction of > 25 years (BPTB p=0.003; HT p=0.048) were found to be significant independent predictors of osteoarthritis. However, no statistically significant correlations were found between the development of osteoarthritis and the clinical outcome or the radiographic stability in both groups. Conclusion: Although ACL reconstruction using BPTB or HT autograft had good clinical results at an average follow-up of 10 years, considerable incidence of radiographic osteoarthritic changes were noted. Various factors such as accompanying meniscal injury, protracted time from injury to reconstruction, more than 25 years old at the time of reconstruction were related to radiographic osteoarthritic changes.