GAIT STABILITY DURING DIRECTION CHANGE WALKING WITH T-POLES IN THE ELDERLY

INTRODUCTION: Falls are the leading cause of injury deaths for the elderly and typically occur when this population is forced into an unbalanced condition, such as changing a direction during gait. It is widely accepted that the elderly are more vulnerable to falls due to age-related declines in balance and gait stability (Hahn & Chou, 2003). Therefore, a better understanding of gait stability mechanics during direction changes would be critical in reducing the incidence of falls among the elderly. One of the most insightful ways to assess gait stability is to use the instantaneous orientation of the line that connects the center of pressure (COP) and whole body center of mass (COM). The angles made by the line with respect to horizontal line (COM-COP inclination angles) are characterized by the whole body position with respect to the supporting foot during gait (Chou, 2006). Recently, telescopestyle walking poles (T-poles) were deemed effective in reducing elderly fall risk factors (Yoon, 2007); however, the effect of T-poles on gait stability is still unknown. The purpose of this study was to investigate the effects of T-poles on elderly gait stability using COM-COP inclination angles in both straight and direction change during gait

THE EFFECT OF HIGH-HEEL SHOES ON LOCAL DYNAMIC STABILITY

INTRODUCTION: High-heeled shoes with a wide variety of heights are worn by Korea women. Even though walking with high-heeled shoes makes woman appear more slender and taller, a narrow toe box, an excessive plantar curvature and a rigid heel cap have been associated with the development of various foot deformities (Stefanyshyn et al., 2000). The effect of walking with high-heeled shoes on foot pressure distribution, muscle EMG, kinematics, and kinetics was investigated in previous studies (Stefanshyn et al., 2000; Liu & Wang, 2004). Few nonlinear dynamic studies have been conducted to detect differences in local dynamic stability as heel height increases. Thus, the purpose of this study was to determine, via a nonlinear analysis, the local dynamic stability present in time series data generated from high-heeled gait

ACCURACY OF THE SOFTWARE GENLOCK WITH DIGITAL CAMCORDERS

Recently, digital camcorders have gained popularity as a viable means of recording movements in video motion analysis, mainly due to the ease of use and reasonably high image resolution. Digital camcorders, however, suffer from a major drawback, lack of the hardware genlock capability. Camcorders thus operate independently from each other and introduce time offsets among themselves. These time offsets in turn violate the requirement of simultaneous observations from multiple cameras in the 3·D analysis, producing erroneous real-life coordinates of the markers. This is especially true in fast motions, in which a small time offset can be translated into a large spatial error, and the time offsets must be corrected before the 3-D reconstruction. The genlock (synchronization) of the cameras can be potentially achieved by a software-based strategy, the software genlock. The purpose of this stUdy was to investigate the accuracy of the software genlock using digital camcorders

GROUND REACTION FORCES DURING “POINTE” IN BALLET

The purpose of this study was to investigate the differences in ground reaction forces between right and left leg during pointe. Fifteen ballet dancers who have no lower limb injury participated in this study. Eight infrared cameras (Qualisys, Sweden) and two force plates (Kistler, Switzerland) were used for a three dimensional motion analysis. Ballet dancers were asked to perform 10 trials of “demi-plie en pointe”. The results showed significant differences in vertical ground reaction forces between right and left leg at maximum ankle extension (E3, ?

THE EFFECT OF SHOULDER MOBILITY ON AGONIST AND SYNERGIST DURING SHOULDER PRESS

The purpose of this study was to investigate the effect of shoulder mobility score on agonist and synergist muscle activation during shoulder press and to provide an underpinning fundamental to optimize the training effect while reducing the risk of injuries when instructing training in the field. The participants were divided to two different groups according to individual shoulder mobility score which is part of the Functional Movement Screen (FMS). There were five participants in the score of 3 group (upper group) and six included in the group with the score of less than 3 (lower group). The results of this study revealed that the shoulder mobility score showed a negative correlation with the ratio of the left and right latissimus dorsi/anterior deltoid muscle activation in the concentric contraction phase (

CORRELATIONS BETWEEN EXPERTS’ SCORING AND BIOMECHANICAL ASSESSMENT IN BALLET MOVEMENT

The purpose of this study was to investigate the relationship between assessment of ballet movement by experts and biomechanical variables. Releve point movement was recorded by a video camcorder (Sony, Japan) for the expert assessment. Eight infrared cameras (Qualisys, Sweden) and two force plates (Kistler, Switzerland) were used for biomechanical analysis. A High reliability in score for flexibility and assistance among three judges was found. Based on the analysis of correlations, flexibility and ROM were positively correlated as the subject who performed wider motion at the ankle achieved higher sores in flexibility from the judges. Negative correlations were found between the judges’ scores in assistance and ankle joint power as well as their scores in balance and COP on the left side. Development of objective and reliable scoring standards in ballet based on the understanding of body movements supported by the verification of scientific method is needed

ALTERATIONS IN JOINT KINEMATICS AND KINETICS DURING DOWNHILL RUNNING

The purpose of this investigation was to find how joint kinematics and kinetics during downhill running change compared to level running. Fifteen recreational runners ran on a force plate imbedded treadmill with three different slopes (0 º, -6º, and -9º) at a controlled speed of 3.2 m/s. Ten steps on each slope were selected for analysis. Increased knee flexion with decreased ankle plantar-flexion and hip flexion was found during downhill running compared to level running. Decreased peak propulsive ground reaction force and posterior impulse were found during downhill running compared to level running. Additionally, increased extension moment with increased negative joint power at the knee and decreased plantar-flexion moment with decreased negative joint power at the ankle were found during downhill running compared to level running

COMPARISON OF ANGULAR KINEMATIC PATTERNS BETWEEN CARVING TURN AND SKIDDING TURN DURING ALPINE SKIING

The purpose of this study was to investigate the movement patterns between segments (lower spine, pelvis, thigh, shank) and ski using the relative angular displacement on anteroposterior and vertical axis. Fourteen alpine ski instructors were participated in this study. Eight inertial measurement units were used to measure kinematic variables. Each skier was asked to perform ten carving turns and ten skidding turns on the groomed 15°slope, respectively. On the vertical axis, relative angular displacement of lower spine-ski was significantly increased during carving turn, whereas relative angular displacement of shank-ski was significantly increased during skidding turn. On the anteroposterior axis, relative angular displacement of lower spine-ski, pelvis-ski and thigh-ski were significantly increased during carving turn

KINEMATIC ANALYSIS OF DIVING BACK PIKE SOMERSAULT IN PLATFORM ACCORDING TO PLAYERS’ SKILL LEVEL

The purpose of this study was to investigate the kinematic difference in Back Pike somersault in platform diving according to players‘ skill level and to assist them to improve performances. Ten Korean diving athletes participated in this study and they were divided into skilled group (n=5) and less-skilled group (n=5) and t-test was performed to find the difference at the moment of take-off between groups. The results showed that the hip extension angle was greater and the extension velocity of knee and hip joints were faster in skilled group compared to less-skilled group. It is recommended, therefore that the flexibility training of hip joint and muscle strength training to enhance extension velocity of knee and hip joints are needed

DIFFERENCES IN TRUNK ANGLES THROUGH DIFFERENT SHOOTING DIRECTIONS IN WATER POLO PENALTY SHOOTING

The purpose of this study was to investigate three-dimensionally the shooter’s trunk motion through 4 different shooting directions. Ten Korean national level water polo players who are right-handed were participated in this study (age, 21.60±3.20 years; weight, 86.30±8.86 kg; height, 1.83±0.05 m). To analyze the shooter’s trunk motion among different target, a three-dimensional motion analysis with six video cameras was performed.The analysis events were coking when the trunk was externally rotated maximally and release moment. A one-way ANOVA with repeated measure was performed as main statistical tests and Bonferroni correction was used as a post-hoc test. The results showed that there was statistically significant difference in trunk angle between left and right shooting directions. Especially, the posterior leaning and external rotation angles of trunk in cocking moment were bigger in left shooting direction compared to right one (p\u3c.05). These results suggest that goalkeepers predict shooting direction more precisely by identifying the trunk posture at coking moment