A COMPARATIVE ANALYSIS ON SELECTED KINEMATICS PARAMETERS BETWEEN THE "SEPAK KUDA" SERVE AND THE "SEPAK SILA" SERVE IN SEPAK TAKRAW

The purpose of this study is to compare selected kinematics parameters between the "Sepak Kuda" and the "Sepak Sila" serves technique in the game of Sepak Takraw. Four international players were videotaped while performing both serves during the 21st SEA Games. Two of the players used the "Sepak Kuda" serve technique while the other two players used the "Sepak Sila". Six synchronized video cameras with a speed of 50 Hz were used. Data was collected using the Peak Motus 2000 System software. Results indicate that the "Sepak Kuda" serve gives a higher post-contact ball velocity compared to that achieved the "Sepak Sila"

A STUDY ON THE ACCURACY OF THREE-DIMENSIONAL SPACE RECONSTRUCTION FOR POLES SYSTEM ON A 6 x 6 m2 FIELD

An investigation on space reconstruction error for the poles system, which covers an area of 6 x 6 m2 field, is carried out using a three video camera system. Two sets of location for the poles are tested. The result of the RMS error shows a superiority of the positioning the control points at the corners of the court, compared to that of the sides of the court

CONTACT TIME AND TAKE-OFF SPEED RELATIONSHIP IN DETERMINING HEIGHT OF JUMP IN JUMPING BADMINTON SMASH

The paper investigates the relationship between the foot contact time with the ground during the planting of foot phase and the horizontal and vertical velocities before take-off to determine an attainable height of jump during a jumping smash performance. World class badminton players were chosen as subjects. Results showed that contact time was found to be about 0.22 s to generate the greatest forward momentum and there was a greater need to convert the horizontal velocity to vertical velocity, as the vertical velocity determines the attainable height of jump

Determining Foot-Ankle Mechanism Design by Mapping the Relationships Among Bones, Joints, and Ground Reaction Force

This work investigates the following questions—why the bones and the joints are arranged in that way, why it is different from other primates, and how could it be imitated to develop a foot-ankle mechanism. Mathematical models were developed and were based on the relationship among the anatomy of bones and joints, the normalized ground reaction forces that acted on certain nodes on the footprint. Using the model, a custom design prosthetic foot was assembled. It was tested on a robot arm that simulated a walking gait. The stance phase cycle performed on the prototype, and the commercial feet were completed within approximately 1.08 seconds and 1.38 seconds, respectively. The techniques used, however, may require further studies because the prototype foot was not tested on patients. At this stage, the techniques are sufficient to justify that the prototype foot design should consist of an ankle-foot mechanism and a flexible keel. Therefore, proper mappings of bones and joints; and modeling of foot biomechanics is found useful in design and development of prosthetic feet activities

THE ANALYSIS OF THE JUMPING SMASH IN THE GAME OF BADMINTON

An investigation on the prevalence of jumping smash in a badminton game is carried out using a six video camera system. The data was collected during the Thomas/Uber Cup 2000 competition, which was held in Kuala Lumpur, Malaysia. Thirteen male players in the single and double competitions were studied. The trials were digitized using the Peak Motus 2000 system. The result from the chi square analysis showed that majority of the jumps and landing occurred in only one foot. And from the correlation analysis, it was found that the angular velocity of the ankle at the maximum value prior to take off was strongly correlated with the center of mass vertical velocity (r =0.546, P =0.001)

A COMPARATIVE STUDY ON KINEMATICS PARAMETERS BETWEEN THE SEPAK KUDA SERVE AND THE SEPAK SILA SERVE IN SEPAK TAKRAW

The most important and effective skill in a sepak takraw game is the serve. In 1995, during the 18th SEA Games, a new technique of serving, 'sepak kuda' was introduced. The sepak kuda serve is well known as the most powerful serve compared to the more traditional serve of 'sepak sila'. The purpose of this study was to make a comparative study on kinematics parameters in both techniques in order to identify specific characteristics of the serves and consequently to give gUidelines for training and mastering especially on the new technique to coaches and players

Preliminary analysis of knee stress in Full Extension Landing

OBJECTIVE: This study provides an experimental and finite element analysis of knee-joint structure during extended-knee landing based on the extracted impact force, and it numerically identifies the contact pressure, stress distribution and possibility of bone-to-bone contact when a subject lands from a safe height. METHODS: The impact time and loads were measured via inverse dynamic analysis of free landing without knee flexion from three different heights (25, 50 and 75 cm), using five subjects with an average body mass index of 18.8. Three-dimensional data were developed from computed tomography scans and were reprocessed with modeling software before being imported and analyzed by finite element analysis software. The whole leg was considered to be a fixed middle-hinged structure, while impact loads were applied to the femur in an upward direction. RESULTS: Straight landing exerted an enormous amount of pressure on the knee joint as a result of the body's inability to utilize the lower extremity muscles, thereby maximizing the threat of injury when the load exceeds the height-safety threshold. CONCLUSIONS: The researchers conclude that extended-knee landing results in serious deformation of the meniscus and cartilage and increases the risk of bone-to-bone contact and serious knee injury when the load exceeds the threshold safety height. This risk is considerably greater than the risk of injury associated with walking downhill or flexion landing activities

THREE-DIMENSIONAL CINEMATOGRAPHIC ANALYSIS: ENLARGING A CALIBRATED VOLUME

Doing research in open games requires a calibrating system as large as the size of the playing court. In this paper a new reference structure, poles system, which could encompass the size of a playing court, is developed. Comparisons between the currently available frame and the poles systems are made. The results showed that the poles are comparable to those obtained using the Peak calibration frame, despite the difference in the dimensions of the structures, the location of the control points, as well as the physical characteristics of the structures

Approximating the relationship among the degree of the reaction forces and the nodes on footprint during a stance phase

This study examined the foot biomechanics that are utilized when foot is in contact with the ground during a stance phase. The purpose of the study was to investigate the normalized ground reaction forces that impacted certain sections and points on the footprint, and to identify patterns in the degrees to which these forces occurred. Foot was modeled in such a manner that a vertex represented a bone and an edge represented a joint, and a graph that depicted the foot was created. Twelve nodes were marked on the footprint and these were linked together to create a gait path. By fusing the graph and the gait path and by manipulating the mathematical models, a profile for an ideal bipedal walking locomotion was developed. A male subject performed bipedal walking through a force plate system in order to obtain the profile that reflected actual bipedal walking. The actual and the proposed profiles were compared and there were significant similarities between the two profiles, with both exhibiting an double-bump pattern. It is therefore viable that the approximation techniques proposed in this work may provide an alternative means over the application of a force plate system to generate a profile for bipedal walking. However, the accuracy and reliability of the results yielded from this technique need further investigation