• Korean Journal of Applied Biomechanics
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• v.25 no.1
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• pp.39-47
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• 2015

Objective : The purpose of this study was to investigate the velocity conversion coefficient and invariance for the optimal phase ratio on the performance of the women's triple jump. Methods : Three-dimensional kinematic data were obtained from the three finalists of the women's triple jumper competition at the 2011 Daegu IAAF World Championships. Computer simulations were performed using the biomechanical model of the triple jump to optimize the phase ratio for the longest actual distance for all athletes with altered velocity conversion coefficients. Results : Top elite triple jumpers showed better technical consistency at the phase ratio. Also, no consistent relationship was observed between the loss in horizontal velocity and the gain in vertical velocity across supporting the three phase. In addition, regardless of the magnitude A1, all athletes were optimized with jump-dominated technique. Finally, as the magnitude of A1 increased, the athletes showed better performance. The obtained overall distance jumped showed the longest actual distance when the optimal phase ratio was transferred from hop-dominated to jump-dominated(the step ratio was 30%~31%), and when the optimal phase ratio was transferred from balanced to jump-dominated(the step ratio was 27%~29%). Conclusion : Future studies need to be conducted in order to explore the active landing motion and the inclination angle of the body with the velocity conversion coefficient simultaneously at each supporting phase.

• Korean Journal of Applied Biomechanics
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• v.25 no.1
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• pp.29-37
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• 2015

Objective : The purpose of this study was to investigate the biomechanical properties of shock absorption strategy and postural stability during the drop landing for each types. Methods : The motions were captured with Vicon Motion Capture System, with the fourteen infra-red cameras (100Hz) and synchronized with GRF(ground reaction force) data(1000Hz). Ten male soccer players performed a drop landing with single-leg and bi-legs on the 30cm height box. Dependent variables were the CoM trajectory and the Joint Moment. Statistical computations were performed using the paired t-test and ANOVA with Turkey HSD as post-hoc. Results : The dominant leg was confirmed to show a significant difference between the left leg and right leg as the inverted pendulum model during Drop Landing(Phase 1 & Phase 2). One-leg drop landing type had the higher CoM displacement, the peak of joint moment with the shock absorption than Bi-leg landing type. As a lower extremity joint kinetics analysis, the knee joint showed a function of shock absorption in the anterior-posterior, and the hip joint showed a function of the stability and shock absorption in the medial-lateral directions. Conclusion : These findings indicate that the instant equilibrium of posture balance(phase 1) was assessed by the passive phase as Class 1 leverage on the effect of the stability of shock absorption(phase 2) assessed by the active phase on the effect of Class 2 leverage. Application : This study shows that the cause of musculo-skeletal injuries estimated to be focused on the passive phase of landing and this findings could help the prevention of lower damage from loads involving landing related to the game of sports.

• Journal of the Korea Convergence Society
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• v.8 no.2
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• pp.149-155
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• 2017

The purpose of this research was to develop the method of media literacy education program based on animation production for the 21 century student. A total of four stages of educational programs were constructed by linking the media literacy education goals and the animation production process through the previous research. First, Acquisition of animation production tools for enhancing media access capability. Second, Animation production practice stage for strengthening creative production capacity. Third, the development of critical understanding stage for presentation and discussion the results. Forth, social sharing stage to strengthen social communication capacity. For the practical application of the education program, it was produced as an educational model for Hanseo University animation summer camp, and was educated by 79 middle school students in Chungcheong province. Based on this research, students improve an analytical ability and help them become active participants by creating their own animations. In future, it will be needed a continuous research on the development of educational programs using various media.

• Physical Therapy Korea
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• v.27 no.2
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• pp.133-139
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• 2020

Background: The gastrocnemius (GCM) is one of the lower extremity muscles that tend to tighten easily. GCM tightness results in limited ankle dorsi-flexion (DF), especially when the knee joint is fully extended. Joint flexibility is determined by the morphological and physiological characteristics of joints, muscles, tendons, and ligaments. Impaired joint flexibility can be attributed to increased susceptibility to muscle injury. High-frequency diathermy is clinically used to reduce pain and muscle tightness and to improve limited range of motion. Objects: This study aimed to investigate the immediate effects of high-frequency therapy in subjects with GCM tightness. Methods: The study was designed as a one-group before-after trial. The subjects included 28 volunteers with GCM tightness (an active ankle DF angle of less than 12°) without any known neurological and musculoskeletal pathologies in the ankle and calf areas. WINBACK Transfer Electrode Capacitive and Resistive Therapy equipment was used to apply high-frequency therapy to the subjects' GCMs for 10-15 minutes. The pennation angle and the fascicle length of the GCM were measured using ultrasonography. The flexibility of the ankle joint, peak torque to the passive ankle DF (Biodex), and soft tissue stiffness (MyotonPRO) were also measured. Results: The pennation angle was significantly decreased following the treatment; however, no significant difference in the fascicle length was found (p < 0.05). The flexibility was significantly increased and both the passive peak torque to passive ankle DF and the soft tissue stiffness significantly decreased (p < 0.05). Conclusion: High-frequency therapy is immediately effective for improving the muscle's architectural properties and functional factors in subjects with GCM tightness. Further longitudinal clinical studies are required to investigate the long-term effects of high-frequency therapy on subjects with GCM tightness from various causes.

• Proceedings of the Korea Contents Association Conference
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• 2006.11a
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• pp.783-787
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• 2006

The 'spatial senses' mean environments and the instinctive responds to objects in the environments. The infancy is an important period to develop the basic capacity of the 'spatial senses'. Since young children can develop the 'spatial senses' throughout the actual and active search, it is essential for them to do experience through their physical actions. This paper proposes four motion based-contents for improving the spatial sense of young children: a bubble game, a cyber goalkeeper game, a mud-huddle game, and a shape recognition game. The proposed four games are implemented to the virtual learning environments. Also, the virtual learning environments utilize the realistic interfaces which can recognize motions of young children and then interact with the games as they do the movement at the virtual environments provided. Using the realistic interfaces not only develops young children's spatial sense but also offers them the pleasure and interest of self-study.

• Physical Therapy Korea
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• v.13 no.2
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• pp.77-84
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• 2006

Although conservative management of congenital muscular torticollis (CMT) has been well documented, relatively little is known about the response to the treatment. The purposes of this case report were to describe the use of a therapeutic approach based on motor development in physical therapy intervention for an infant with CMT and to report the result of the treatment. The patient was a 20-day-old baby boy with left CMT presenting muscular mass in the left sternocleidomastoid muscle. The angle of the lateral head tilt was 20 degrees. The size of muscular mass was 5.3 mm in ultrasonography. Intervention included ultrasonic therapy, soft tissue massage, passive and active range of motion exercises, motor developmental therapy, and parent instruction. The procedures of motor developmental therapy and changes in the amount of lateral head tilt were documented using photography. The size of the mass was decreased to .3 mm before the 5-month follow-up. The patient also maintained a midline head position in the supine position and a midline head alignment during all functional activities. A therapeutic approach based on motor development is a beneficial method for reducing an asymmetrical head and neck position, and facilitating normal development as a component of physical therapy intervention.

• Physical Therapy Korea
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• v.19 no.3
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• pp.98-104
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• 2012

The aim of this study was to examine the effects of repeated passive movement (RPM) of different velocities on the improvement of knee joint position sense (JPS) in post-stroke patients with hemiplegia, thereby investigate the possibility of clinical application in the initial stage of rehabilitation for patients with post-stroke hemiplegia. Thirteen hemiplegic patients participated in this study. For the subjects' knee JPS tests, a passive angle reproduction test and an active angle reproduction test were performed prior to and after the intervention, which involved 30 repetitions of passive full-range-of-motion flexion and extension exercise of the knee joints at randomized degrees of $0^{\circ}/s$, $45^{\circ}/s$, and $90^{\circ}/s$. Paired t-test analysis was done in order to compare changes in the pre- and post-intervention knee JPS. One-way repeated analysis of variance was used in order to compare changes in JPS after intervention at three different movement velocities. The level of significance was set at .05. The result was that the subjects' post-intervention knee JPS significantly improved after the RPM exercise at a $45^{\circ}/s$ and a $90^{\circ}/s$ relative to the RPM exercise $0^{\circ}/s$ (p<.05). JPS changes with RPM intervention at the rapid velocity of $90^{\circ}/s$ were most increased, suggesting the most effective enhancement in knee JPS is with intervention at the velocity (p<.05). Therefore, RPM intervention at a half or higher velocity improved stroke patients' knee JPS. During the initial stage of rehabilitation for patients with post-stroke hemiplegia, the efficient application of the RPM exercise at a half or higher velocity will be possible.

• Clinics in Shoulder and Elbow
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• v.20 no.4
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• pp.183-188
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• 2017

Background: To evaluate the clinical outcomes and associated repair integrity in patients treated with arthroscopic repair for a transtendinous rotator cuff tear followed by resection of the remnant rotator cuff tendon. Methods: Between July 2007 and July 2011, we retrospectively reviewed patients who were treated for transtendinous full-thickness tears in the tendinous portion of the rotator cuff by arthroscopic repair. Clinical outcomes were evaluated using the American Shoulder and Elbow Surgeons (ASES) score, the Shoulder Rating Scale of the University of California at Los Angeles (UCLA), the Constant-Murley score, a visual analogue scale (VAS) pain score, and range of motion (ROM). The repair integrity was determined by magnetic resonance imaging or ultrasonography. Results: There were 19 shoulders with transtendinous full-thickness tears in the tendinous portion of the rotator cuff. The ASES, UCLA, Constant-Murley, and VAS pain scores showed significant improvements in function and symptoms (all p<0.001). The active ROM for forward flexion and abduction was also significantly improved (p=0.002 and p<0.001, respectively). The postoperative radiological examination showed cuff integrity without a re-tear in 68.4% of patients. However, the UCLA, ASES, and Constant-Murley scores were not significantly different between healed and re-torn group (p=0.530, p=0.885, and p=0.262, respectively). Conclusions: Although repair of transtendinous rotator cuff tears followed by resection of the remnant rotator cuff tendon in the footprint has a relatively high re-tear rate, no significant difference was observed in the short-term clinical results between the re-tear and healed groups.

• Journal of the Korean Society of Physical Medicine
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• v.9 no.4
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• pp.485-492
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• 2014

PURPOSE: This study aimed to examine the pain, range of motion (ROM), upper extremity task performance, and functional levels of patients after rotator cuff repair according to the timing of a closed chain exercise thereby presenting basic data for an effective rehabilitation program. METHODS: The intervention was applied three times per week, one hour per day, for four weeks to 40 participants, 78 of whom had undergone rotator cuff repair. The participants were divided into four groups and assigned to usual general physical therapy and an open chain exercise. Group I consisted of the open chain exercise only. The closed chain exercise was applied to group II after the 4 times, group III after the 7 times, group IV after the 10 times. Measurement were used ROM, visual analogue scale (VAS), box and block test (BBT), and shoulder pain and disability index (SPADI). A one-way analysis of variance was conducted to test differences. RESULTS: There were significant differences in the internal/external rotation between group I and group II. The VAS significantly differed between group II and group I, group III, and group IV. The BBT results of group II and group I were significantly different compared to those of group IV. The SPADI significantly differed between group II and group I and between group II and group IV. CONCLUSION: The closed chain exercise was effective for patients following rotator cuff repair from the second week after active exercise was prescribed, verifying its applicability in rehabilitation programs.

• Korean Journal of Applied Biomechanics
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• v.15 no.1
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• pp.127-142
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• 2005

The purpose of this study was to analysis biomechanics of the lower extremities injury the heights(40cm, 60cm, 80cm) of jump box as performed depth jump motion by 6 females aerobic athletes and 6 non-experience females students. The event of depth jump were set to be drop, landing and jump. The depth jump motions on the force plate were filmed using a digital video cameras, and data were collected through the cinematography and force plate. On the basis of the results analyzed, the conclusions were drawn as follows: 1. The landing time of skill group was shorter than unskill group at 40cm, 60cm drop height during drop-landing-jump phase especially. The landing time of 60cm drop height was significant between two group(p<.05). 2. The peak GRF of sagittal and frontaI direction following drop height improve was variety pattern and the peak vertical force of 40cm drop height was significantly(p<.05). 3. The magnitude of peak passive force was not increase to change the drop height. 4. The peak passive forces was significant at 40cm drop height between two groups(p<.05)