• Journal of Korean Neurosurgical Society
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• v.47 no.1
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• pp.7-10
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• 2010

Objective: In this study, we present a simple closed head injury model as a two-stage experiment. The height of the weight drop enables gradation of head trauma severity. Methods: The head injury device consists of three parts and there are three adjustable parameters-weight (100-600 g). height of fall (5-100 cm) and elasticity of the springs. Thirty male Wistar rats underwent monitoring of intracranial pressure with and without induction of the head injury. Results: The weight drop from 45 to 100 cm led to immediate seizure activity and early death of the experimental animals. Severe head injury was induced from 40 cm weight drop. There was 50% mortality and all surviving rats had behavioral deterioration. Intracranial pressure was 9.3${\pm}$3.76 mmHg. Moderate head injury was induced from 35 cm, mortality decreased to 20-40%, only half of the animals showed behavioral pathology and intracranial pressure was 7.6${\pm}$3.54 mmHg. Weight drop from 30 cm caused mild head injury without mortality and neurological deterioration. Intracranial pressure was slightly higher compared to sham group- 5.5${\pm}$0.74 mmHg and 2.9${\pm}$0.81 mmHg respectively. Conclusion: This model is an eligible tool to create graded brain injury with stepwise intracranial pressure elevation.

• The Korean Journal of Pain
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• v.32 no.1
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• pp.12-21
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• 2019

Spinal cord contusion injury is one of the most serious nervous system disorders, characterized by high morbidity and disability. To mimic spinal cord contusion in humans, various animal models of spinal contusion injury have been developed. These models have been developed in rats, mice, and monkeys. However, most of these models are developed using rats. Two types of animal models, i.e. bilateral contusion injury and unilateral contusion injury models, are developed using either a weight drop method or impactor method. In the weight drop method, a specific weight or a rod, having a specific weight and diameter, is dropped from a specific height on to the exposed spinal cord. Low intensity injury is produced by dropping a 5 g weight from a height of 8 cm, moderate injury by dropping 10 g weight from a height of 12.5-25 mm, and high intensity injury by dropping a 25 g weight from a height of 50 mm. In the impactor method, injury is produced through an impactor by delivering a specific force to the exposed spinal cord area. Mild injury is produced by delivering $100{\pm}5kdyn$ of force, moderate injury by delivering $200{\pm}10kdyn$ of force, and severe injury by delivering $300{\pm}10kdyn$ of force. The contusion injury produces a significant development of locomotor dysfunction, which is generally evident from the $0-14^{th}$ day of surgery and is at its peak after the $28-56^{th}$ day. The present review discusses different animal models of spinal contusion injury.

• Korean Journal of Applied Biomechanics
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• v.21 no.2
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• pp.197-205
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• 2011

Various jumping and landing motions are shown during sports event. But most previous studies have not considered landing height and distance simultaneously. The purpose of this study was to identify the effects of landing height and distance on knee injury mechanism. Fourteen male(age: $28.86{\pm}1.99$ yrs, height: $177.00{\pm}4.69$ cm, weight: $76.50{\pm}6.41$ kg) participated in this study. The subjects attempted drop landing task onto the ground from 30 cm to 45 cm heights and to 20 cm to 40 cm distances. The results were as follows. First, higher drop landing height and longer distance showed greater degree of maximal knee flexion and valgus. Second, higher drop landing height and longer distance showed greater maximal knee extension moment and varus moment. Third, higher drop landing height and longer distance showed larger maximal knee absorption power. Lastly, higher drop landing height showed increased Peak GRF. Landing height was more related to the cause of injury, which was indicated by increased maximal knee extension moment, peak GRF and maximal knee absorption power. Landing distance was also associated with increased knee valgus moment and absorption power during landing. These results suggest that landing height and distance may be the cause of injury.

• 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.

• The Journal of Korean Physical Therapy
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• v.16 no.2
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• pp.72-89
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• 2004

The purposes of this study were to test the effect of balance training and environmental enrichment on motor performance after traumatic cerebellar injury in the rat. Traumatic cerebellar injury was induced by weight drop model and after operation they were housed in individual standard cages for 24 hours. Twenty two Sprague-Dawley rats were randomly assigned into control and experimental groups. The control group was housed in standard cage for 7 days. The experimental group I was housed in standard cage after balance training for 7 days. The experimental group II was housed in environmental enrichment cage after balance training for 7 days. Vestibular drop test and tilting plane test was examined at preoperation, on 1st day after operation and 7th day after operation to the rats. The results of this experiment were as follows: 1. In motor behavioral test, at preoperation and on 1 day after operation, the outcomes were not different among the groups. But on 7th day after operation, the outcomes of group I were better than that in control group, and group II were better than group I. These results suggest that behavioral motor outcome by simultaneously application of balance training and environmental enrichment in traumatic cerebellar injured rats were more improve than that by just balance training.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.16 no.1
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• pp.1-8
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• 2010

Purpose : This study aimed to examine the relationships among five clinical measures for functional alignment of the lower extremity. Methods : Thirty healthy subjects (15 males and 15 females) were recruited for the study. The five clinical measures of functional alignment of the lower extremity included navicular drop, quadriceps angle, internal rotation of hip, and anterior and lateral pelvic tilt angles. The level of navicular drop was calculated by the difference between the height of the navicular bone in the sitting (non-weight bearing) and standing (weight bearing) positions. The quadriceps angle and internal rotation of hip were measured using a standard goniometer with photographic markers while the subjects were lying in a prone position on a table with their knee at $90^{\circ}$ flexion. Anterior and lateral pelvic tilt angles were determined using a inclinometer. Results : Correlation and a simple linear regression analysis were used to assess relationships between the clinical measures. There were significant correlations between navicular drop and quadriceps angle (p<.05), between navicular drop and internal rotation of hip (p<.05), and between quadriceps angle and internal rotation of hip (p<.01). In simple linear regression analysis, the navicular drop appeared to be a factor affecting the quadriceps angle and internal rotation of hip (p<.05). The findings suggest that navicular drop has a great impact on lower extremity alignment. Conclusion : This study might help us to examine lower extremity function and clarify its role as a potential injury risk factor.

• PNF and Movement
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• v.4 no.1
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• pp.51-62
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• 2006

Purpose : The purposes of this study were to test the effect of proprioceptive and vestibular sensory input on expression of BDNF after traumatic brain injury in the rat. Subject : The control group was sacrificed at 24 hours after traumatic brain injury. The experimental group I was housed in standard cage for 7 days. The experimental group II was housed in standard cage after intervention to proprioceptive and vestibular sensory(balance training) for 7 days. Method : Traumatic brain injury was induced by weight drop model and after operation they were housed in individual standard cages for 24 hours. After 7th day, rats were sacrificed and cryostat coronal sections were processed individual1y in goat polyclonal anti-BDNF antibody. The morphologic characteristics and the BDNF expression were investigated in injured hemisphere section and contralateral brain section from immunohistochemistry using light microscope. Result : The results of this experiment were as follows: 1. In control group, cell bodies in lateral nucleus of cerebellum, superior vestibular nucleus, purkinje cell layer of cerebellum and pontine nucleus changed morphologically. 2. The expression of BDNF in contralateral hemisphere of group II were revealed. 3. On 7th day after operation, immunohistochemical response of BDNF in lateral nucleus, superior vestibular nucleus, purkinje cell layer and pontine nucleus appeared in group II. Conclusion : The present results revealed that intervention to proprioceptive and vestibular sensory input is enhance expression of BDNF and it is useful in neuronal reorganization improvement after traumatic brain injury.

• Korean Journal of Applied Biomechanics
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• v.31 no.2
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• pp.126-132
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• 2021

Objective: The purpose of this study was to investigate how three gaze directions (bottom, normal, up) affects the coordination and stability of the lower limb during drop landing. Method: 20 female adults (age: 21.1±1.1 yrs, height: 165.7±6.2 cm, weight: 59.4±5.9 kg) participated in this study. Participants performed single-leg drop landing task on a 30 cm height and 20 cm horizontal distance away from the force plate. Kinetic and kinematic data were obtained using 8 motion capture cameras and 1 force plates and leg stiffness, loading rate, DPSI were calculated. All statistical analyses were computed by using SPSS 25.0 program. One-way repeated ANOVA was used to compared the differences between the variables in the direction of gaze. To locate the differences, Bonferroni post hoc was applied if significance was observed. Results: The hip flexion angle and ankle plantar flexion angle were significantly smaller when the gaze direction was up. In the kinetic variables, when the gaze direction was up, the loading rate and DPSI were significantly higher than those of other gaze directions. Conclusion: Our results indicated that decreased hip and ankle flexion angles, increased loading rate and DPSI when the gaze direction was up. This suggests that the difference in visual information can increase the risk of injury to the lower limb during landing.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.219-224
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• 2006

In this paper, to verify the safety of railway vehicle structure, we describe the test methods of roof structure. The purpose of GM/RT 2100' missile protection article is to minimise the risk of injury which could result from the penetration into a vehicle body by missile such as stones and bricks. we carried out weight drop test on the roof structure in accordance with GM/RT 2100. The test results showed that the penetration did not occer.

• PNF and Movement
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• v.5 no.1
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• pp.9-17
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• 2007

Purpose : The purpose of this study was to test the effect of balance training for proprioceptive and vestibular sensory stimulation and therapeutic environment on expression of BDNF after traumatic brain injury in the rat. Subject : Twelve Sprague-Dawley rats were randomly assigned into group I and group II. After traumatic brain injury, group I was housed in standard cage for 7 days. Group II was housed in therapeutic cage after balance training for 7 days. Method : Traumatic brain injury was induced by weight drop model and after operation they were housed in individual standard cages for 24 hours. After 7th day, the rats were sacrificed and cryostat coronal sections were processed individually in goat polyclonal anti-BDNF antibody. The morphologic characteristics and the BDNF expression were investigated in injured hemisphere section from immunohistochemistry using light microscope. Result : Immunohistochemical response of BDNF in lateral nucleus, purkinje cell layer, superior vestibular nucleus and pontine nucleus appeared very higher in group II than in group I Conclusion : The present result revealed that simultaneously application of balance training for proprioceptive and vestibular sensory stimulation input and therapeutic environment in traumatic brain injured rats is enhance expression of BDNF and it is facilitates neural plasticity.