THE INTERRELATIONSHIP OF JOINT STIFFNESS IN DROP JUMP UNDER DIFFERENT CONDITIONS: A SINGLE-SUBJECT DESIGN

The purpose of this study was to examine the relationship between leg stiffness and joint stiffness in the various conditions of drop jump. A women’s athlete was recruited as the subject and asked to perform drop jump from different height of box to another box in different horizontal distance between them. The leg stiffness is influenced on the contact time and relates to knee and ankle joint stiffness. The change in leg length is greater at great horizontal distance and peak ground reaction force is greater at higher box of jump off and up. The contact time was also related to the horizontal distance and to the knee and ankle joint stiffness, peak ankle joint torque and minimum knee joint angle. These might suggest that leg stiffness influenced by ankle and knee joint stiffness due to peak ankle joint torque and knee joint angular displacement to adjust the conditions of drop jump

EFFECT OF SHOES AND TIGHTS WITH THE SUPPORT FUNCTION ON SUPPORT LEG DURING RUNNING

The study aimed to clarify the effect of shoes (WS) and tights (BT) with the support function on support leg during running. The subjects, eight female Japanese runners, ran for 1-min periods on a treadmill. Motion, electromyography (EMG), acceleration and angular velocity were recorded. The following results were obtained: 1) there was difference in the pronation angle between support shoes and non-support shoes. 2) There was difference in angle of lower leg in frontal plane between support shoes and non-support shoes. 3) Combination of WS and BT might decrease angle of the foot and shank in frontal plane and stabilize the trunk, but the effect varies depending on subjects

MECHANICAL WORK CALCULATION METHODS TO EVALUATE DISTANCE RUNNERS

The main purpose of this study was to discuss mechanical work calculation methods for evaluating the effectiveness of running at six different speed. Nineteen male middle and long distance runners were participated in the study, as subjects. Biomechanical measurements were in order to record running motion and ground reaction force. Mechanical work was calculated using two methods: the joint torque power method (WTP) and the mechanical energy method (WME). Physiological measurements were recorded using submaximal and maximal incremental exercise tests on a treadmill. These results were as follows: 1) WTP was significantly larger than WME. 2) WTP/W/TIME was stronger related to velocity and aerobic demands. These findings suggest that regression equation between WTP/W/TIME and velocity evaluate effectiveness of distance runner

EFFECT OF BIOMECHANICAL FACTORS ON ENERGY COST DURING RUNNING AT VARYING INCLINES

This study aimed to investigate the characteristics of muscular activity of a support leg that affected energy cost at different inclinations of a treadmill while running. Eleven male Japanese distance runners ran on a treadmill at 13.5 km·h��1 for 3 min at five different inclinations���� ��6%, ��3%, 0%, +3%, and +6%. Running kinematics, electromyography (EMG), expired gases, and blood lactate levels were measured. The following results were obtained: 1) the energy cost and integrated EMG (iEMG) of the vastus lateralis (VL) muscle increased with increasing inclination, and 2) iEMG of the VL and gluteus maximus (GM) muscles positively correlated with the vertical displacement of the body’s center of mass and with a maximal angle of the thigh during the contact phase. Thus, the muscular activities of VL and GM might increase the energy cost while running at an inclination

EFFECT OF A BlOMECHANlCAL FACTOR ON ENERGY EXPENDITURE BY DISTANCE RUNNERS DURING REPEATED VERTICAL JUMPS

This study aimed to clarify a biomechanical factor that would affect energy expenditure during repeated vertical jumps. The subjects, nine male Japanese distance runners, jumped for 3-min periods on a force platform under four different conditions. Motion and electromyography (EMG) data were recorded with a high-speed camera and surface electrodes, respectively. The following results were obtained: 1) the integrated EMG of the rectus femoris and vastus lateralis was greater in the Low and Decline conditions than in the High and Incline conditions, and 2) mechanical work at the ankle was greater in the High and Incline conditions than in the Low and Decline conditions. Thus, increased knee extensor muscular activity may increase the energy expenditure, and the stretch-shortening contraction of the gastrocnemius muscle may be more efficient

ESTIMATION OF THE CENTER OF MASS AND PELVIS MOVEMENT IN RUNNING USING AN INERTIA SENSOR MOUNTED ON SACRUM

The purpose of this study was to compare the center of mass and pelvis movement measured by the inertia sensor, motion capture, and ground reaction force during running. Linear movements of the center of mass and pelvis rotation were measured by motion capture system and the inertia sensor mounted on sacrum for thirteen distance runners. Vertical movement of the sensor was well coincident with the center of mass but lateral and forward/backward movements were overestimated by the sensor. The forward tilt, tangular displacement and velocity of pelvis in a running cycle were almost same in the values by motion capture and sensor with some variances by the mounted position. It would be suggested that the inertia sensor is useful to evaluate the distance running motion with filtering and modification of offset and parameter relationship for individual

Local Atomic Structures around Implanted Phosphorus Atoms in Diamond Analyzed by X-ray Absorption Near Edge Structure

Formation of highly controlled p-type and n-type conductive layers in diamond by ion implantation technique has been strongly desired for realizing diamond-based electronic devices for decades; however practically available doping condition has not been found especially in n-type doping. In this study, we comprehensively determined the local structures and depth profiles of implanted P atoms as n-type dopant to find out the origin of inactivation of implanted P atoms. The local structure around the implanted P atoms was analyzed by X-ray absorption fine structure using synchrotron-radiation-light and the first-principle calculation based on density functional theory. We found at least four components for all prepared samples in the near edge X-ray absorption structure, suggesting that implanted P atoms locate in four different chemical environments. We eventually assigned all the components by comparing the simulated X-ray absorption with the first-principle theoretical calculation: one of the components corresponds to active phosphorus atom in the substitutional site, and others are the elemental P-P bonds and some defect complexes probably acting as inactive species for n-type dopant. These facts suggest that the knowledge of local structure of implanted P atoms and control of them are substantially important to reduce the inactivation factors of the implanted dopants.Full-Length Paper　By a grant from Research Institute for Integrated Science, Kanagawa Universitydepartmental bulletin pape

CURRENT-VOLTAGE PROPERTIES OF SCHOTTKY CONTACT FORMED BY COPPER LAYER DEPOSITED ON ION-IMPLANTED P-TYPE DIAMONDS

We have formed a Schottky contact on p-type diamond substrates doped only by boron ion implantation process. The doping concertation in the drift layer was 4×10^18 cm^-3 and that beneath the Ohmic contact layer was about 1×10^21 cm^-3 in order to reduce the contact resistance at the Ohmic contact. We investigate the rectifying properties for the Schottky electrode fabricated by copper layer. The observed current between two Ohmic electrodes linearly depended on the applied voltage. From the I-V characteristics between the Ohmic and Schottky contacts, the rectification behavior was not clearly observed for the case of copper electrode, and rectification ratio, which is the current ratio of forward direction to reverse direction, was considerably low

A Retrospective Analysis of Transfusion Management for Obstetric Hemorrhage in a Japanese Obstetric Center

Background. Since cryoprecipitate, fibrinogen concentrate, or recombinant activated factor VII is not approved by public medical insurance in Japan, we retrospectively assessed blood product usage in patients with obstetric hemorrhage at our tertiary obstetric center. Material and Methods. 220 patients with obstetric hemorrhagic disorders who underwent blood product transfusion in our institution during a 5-year period were reviewed for the types and volumes of blood products transfused. Results. There was a significant positive correlation (P< 0.001) between the volume of RCC (red blood cell concentrate) transfused and that of FFP (fresh frozen plasma), irrespective of underlying obstetric disorders. The median of FFP to RCC ratio in each patient was 1.3–1.4, when 6 or more units of RCC were transfused. Conclusions. In transfusion for massive obstetric hemorrhage in terms of appropriate supplementation of coagulation factors, the transfusion of RCC : FFP = 1 : 1.3–1.4 may be desirable