• Korean Journal of Applied Biomechanics
• /
• v.20 no.3
• /
• pp.311-318
• /
• 2010

This study examined the double piked dismount among the landing techniques of parallel bars based on three-dimensional motion analysis. Four male national gymnasts were the subjects. This study was performed to provide quantitative data highlighting players strengths and weaknesses to enable more stable landing technique. The variables analyzed were the position and velocity of center of gravity(CG) and angles of shoulder joints, hip joints, and trunk. The results are as follows: S1 secured the height of flight with fast vertical rise. After the easy spin in the air, he conducted a stable landing maintaining a proper hip joints angle. S2, S3, and S4, however, began the backward somersault already before leaving the bars, so they moved backward greatly making it more difficult to achieve a higher flight path. As a result, they couldn't control the velocity of their backward movement at landing. For a stable landing, they have to maintain the negative shoulder angle when rising, minimize both antero-posterioror side-to-side movements by doing a strong tap using hip joints, to secure the height of flight before the somersault. Results also show that at the descent, they should conduct rapid spinning by increasing their shoulder and hip joints to the maximum while controlling their velocity.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 1999.06a
• /
• pp.43-48
• /
• 1999

To clarify the motion characteristics of free-style Okinawan dance“Kachaasi”, first the subjective impression was quantitatively evaluated with semantic differential technique to cluster its types. Then, the contingency of joint rotation in shoulder, elbow and wrist joints was examined with multivariate autoregressive model. The time-series data of positions and angels of three joints were calculated according to the deforming conditions and shielding directions of the ring lights. As the results, in an excellent dancer, the motions of shoulder and elbow were highly synchronized and smoothly controlled. The low-frequency output of the shoulder and elbow were mutually interacted. Meanwhile, the wrist behaved independently of other joints' rotation.

• Journal of International Academy of Physical Therapy Research
• /
• v.2 no.1
• /
• pp.229-236
• /
• 2011

The purpose of this study was to comparatively analyze the active stability of shoulder joints according to the frequency of overhead motions, such as serving and spiking, engaged in by female professional volleyball athletes who play different positions, and to provide the results as the basic data for developing exercise programs to prevent shoulder joint injuries. The subjects of this study were 50 Korean female professional volleyball players and positions were as follows: left and right attackers, centers, setters, and liberos. The external rotation and internal rotation muscle strength and muscle strength ratios of the dominant and non-dominant arms of all subjects were measured using Biodex. The results of this study are as follows: Frist, no significant differences were found in the internal and external rotation muscle strength of the dominant and non-dominant arms between positions. Second, for the shoulder joint muscle strength ratio of the dominant arm, by position, the setter showed significantly greater stability compared to the other positions. Third, for the shoulder joint muscle strength ratio of the non-dominant arm, by position, no significant difference in stability between positions was found. Fourth, it was found that the dominant arm had significantly greater instability of the shoulder joint than the non-dominant arm for attackers and centers, but no significant difference was found for setters and liberos. This study comparatively analyzed the muscle strength ratios of the external/internal rotations and dominant/non-dominant arms, which can determine the stability of the shoulder joints between female professional volleyball playing positions that engage in jumps and spikes using only the dominant hand and positions that do not.

• Journal of The Korean Society of Integrative Medicine
• /
• v.8 no.3
• /
• pp.1-10
• /
• 2020

Purpose : The purpose of this study is to analyze the corrective effect of the general coordinative manipulation (GCM) joint intervention model on distort leg with imbalance of the lower extremity joints, pelvic and shoulder girdles, and lumbar spine. Methods : The study used a comparative analysis of the size of the distort leg and the imbalance of the lower extremity joints, pelvic and shoulder girdles, and lumbar spine before and after the application of the GCM joint intervention model. A total of 31 subjects from movement center G and the department of physical therapy at university M were selected as research subjects, and they were divided into two groups. The GCM joint intervention model was applied to 18 subjects in the bow knee group and 13 subjects in the knock knee group. The two groups received daily intervention three times a week for four weeks. The corrective effect of the GCM joint intervention model for each type of distort leg was compared and analyzed. Results : The effects of the GCM joint intervention model in correcting bow knee and knock knee with knee deformation and imbalance of the lower extremity joints, pelvic and shoulder girdles, and lumbar spine were significant in most domains (p<.05). The correlation between the bow knee and knock knee groups showed significance in most domains (p<.05). Conclusion : The GCM joint intervention model showed significant corrective effect in the bow knee and knock knee groups in terms of knee deformation, lower extremity joints, pelvic and shoulder girdles, and lumbar spine (p<.05).

• Physical Therapy Rehabilitation Science
• /
• v.8 no.2
• /
• pp.79-85
• /
• 2019

Objective: The purpose of this study was to investigate the relationship between physical features, strength, function, and upper extremity musculoskeletal pain during rehabilitation of manual wheelchair users with spinal cord injuries. Design: Cross-sectional study. Methods: The degree and frequency of upper extremity musculoskeletal pain were measured in persons with spinal cord injuries using manual wheelchairs with the use of questionnaires. The pain scores of the hand, wrist, and shoulder joints were calculated by multiplying the seriousness and frequency of pain. We collected data on the manual muscle test, Spinal Cord Independent Measure-III, and the Body Mass Index. Statistical analysis was performed by descriptive analysis and Pearson's correlation analysis. Results: A total of 47 patients participated in this study and the neurological level of the injuries ranged from C2 to S5. Pain in the shoulder joints was the most common in persons with tetraplegia and paraplegia. Pain was experienced as mild to moderate, and occurred one or more times a week. Of the 32 persons with paraplegia, the most common area of complaint was the shoulder. Of the 15 persons with paraplegia, the shoulder joints were the most common site of pain. The independence levels of the persons with spinal cord injuries were highly correlated to muscle strength levels (p<0.05). Conclusions: This study investigated upper extremity musculoskeletal pain during rehabilitation of manual wheelchair users with spinal cord injuries and the relationship between physical features, strength, and function. In most persons with spinal cord injuries, pain and frequency of shoulder joints were high and pain levels were also related to functional levels.

• Clinics in Shoulder and Elbow
• /
• v.4 no.2
• /
• pp.196-198
• /
• 2001

Synovial chondromatosis is the chondroid metaplasia of the synovial membrane, Large joints such as the knee and hip are commonly involved. Synovial chondromatosis very rarely develops within the shoulder joints. We have experienced the synovial chondromatosis developed in the right subscapular recess communicating the shoulder joint of a 30 year-old-female who was diagnosed by plain radiograph, MRI and microscopic findings, and then treated by arthroscopic synovectomy and removal of loose bodies.

• Clinics in Shoulder and Elbow
• /
• v.10 no.1
• /
• pp.140-145
• /
• 2007

Pigmented villonodular synovitis(PVNS) is a benign proliferative lesion, involving synovial tissue in joints, tendon sheaths, and bursae. Pigmented villonodular synovitis is a rare and usually monoarticular condition and primarily affects the knee joint and hand. Polyarticular PVNS appears in less than 1% of all case and its occurrence in the shoulder is rare(<2%). We present a 64-year-old male who had pigmented villonodular synovitis of both shoulder joints, which was treated by arthroscopic total synovectomy.

• Korean Journal of Applied Biomechanics
• /
• v.26 no.1
• /
• pp.39-50
• /
• 2016

Objective: The purposes of this study were to compare the kinematics of a two-arm kettlebell swing between experts and beginners and to identify the correct postures and biomechanical key points in an attempt to prevent sports injuries induced by a kettlebell swing. Methods: Four experts (height, $169.7{\pm}1.5cm$; weight, $70.5{\pm}1.8kg$; age, $32.0{\pm}1.0years$) licensed to teach kettlebell exercises and three beginners (height, $173.7{\pm}4.1cm$; weight, $78.3{\pm}3.8kg$; age, $30.0{\pm}1.4years$) with no kettlebell exercise experience participated in this study. Each participant performed 15 repetitions of a two-arm kettlebell swing using a 16-kg weight. Joint angles, angular velocities, and peak angular velocity sequences were calculated and compared between the two groups. Results: Large ranges of motion (ROM) of the pelvic angle and hip joints were detected in the experts, while beginners showed greater ROM of the shoulder joint. Peak angular velocity magnitudes and sequences were significantly different between the two groups. Experts lifted the kettlebell upward using the hip joints, pelvis, and shoulder joints (proximal to distal order) sequentially and lowered it using the reverse order of peak angular velocities from the shoulder to hip joints. Conclusion: Mobility of the pelvic segment and hip joint are required, while stability of the other joints is needed to produce appropriate two-arm kettlebell swings. The activation and coordination of the gluteal and hamstring muscles are key points in kettlebell exercises.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.2
• /
• pp.970-977
• /
• 2015

The purpose of this study was to investigate biomechanical factors on key motions in K-Pop dance(BoA's No.1). A professional choreographer who was BoA's K-Pop No. 1 dance participated in this study. ROMs(range of motion) of shoulder and elbow joints in AP direction were greater than other joints. Those of trunk and pelvis in ML direction were the greatest of other directions. The velocity of CoG in SI direction was greater than other directions, and also max angular velocities of shoulder, elbow, knee, and hip joints in AP direction were the greatest of all directions. But ROM and angular velocity of ankle joint were very small. Max rotational powers of shoulder and knee joints were larger than other joints.

• Biomaterials and Biomechanics in Bioengineering
• /
• v.3 no.2
• /
• pp.115-127
• /
• 2016

Shoulder pain, injury and discomfort are public health and economic issues world-wide. The function of these joints and the stresses developed during their movement is a major concern to the orthopedic surgeon to study precisely the injury mechanisms and thereby analyze the post-operative progress of the injury. Shoulder is one of the most critical joints in the human anatomy with maximum degrees of freedom. It mainly consists of the clavicle, scapula and humerus; the articulations linking them; and the muscles that move them. In order to understand the behavior of individual muscle during abduction arm movement, an attempt has been made to analyze the stresses developed in the shoulder muscles during abduction arm movement during the full range of motion by using the 3D FEM model. 3D scanning (ATOS III scanner) is used for the 3D shoulder joint cad model generation in CATIA V5. Muscles are added and then exported to the ANSYS APDL solver for stress analysis. Sensitivity Analysis is done for stress and strain behavior amongst different shoulder muscles; deltoid, supraspinatus, teres minor, infraspinatus, and subscapularies during adduction arm movement. During the individual deltoid muscle analysis, the von Mises stresses induced in deltoid muscle was maximum (4.2175 MPa) and in group muscle analysis it was (2.4127MPa) compared to other individual four rotor cuff muscles. The study confirmed that deltoid muscle is more sensitive muscle for the abduction arm movement during individual and group muscle analysis. The present work provides in depth information to the researchers and orthopedicians for the better understanding about the shoulder mechanism and the most stressed muscle during the abduction arm movement at different ROM. So during rehabilitation, the orthopedicians should focus on strengthening the deltoid muscles at earliest.