クローン病患者の非炎症部空腸組織におけるヒトαディフェンシ６の減少

広島大学(Hiroshima University)博士(医学)Doctor of Philosophy in Medical Sciencedoctora

EFFECTS OF STRETCH-SHORTENING CYCLE DURING TRUNK-TWIST EXERCISE USING DIFFERENT LOADS

The purpose of this study was to investigate the effects of stretch-shortening cyde (SSC) movement during bunk-twist and whether the effects change on increasing the loads by using a special trunk-twist machine. Twenty-one male college students performed trunktwist exercise with 3 loads. Participants performed this exercise for each load by using SSC and not using SSC (CON). Kinematic and kinetic data were recorded using Vimn system (250 Hz) and force platform (1,000 Hz). The following effects of SSC for this exercise were observed: (1) peak bar angular velocity was not potentiated by SSC, but SSC contributed to the acceleration of bar angular velocity and (2)for heavy loads, SSC did not affect mean angular velocity of the bar, upper trunk and pelvic rotation. Moreover, peak joint torque power of trunk-twist significantly decreased with heavy loads

Effects of drop height and load on ground reaction force and joint kinetics of the lower extremity during the drop clean

The purpose of this study was to identify the characteristics of lower extremity joint kinetics during the drop clean based on the plyometric theory. Twelve male track-and-field athletes performed the drop clean under four conditions. Kinematic and kinetic data were collected using a Vicon motion system (250 Hz) and force platforms (1,000 Hz). The results of these analyses were as follows:　(1)The peak vertical ground reaction force, joint torque of the ankle joint, and torque power of the hip and ankle joints during the drop clean were significantly greater than those during the hang power clean.　(2)During the drop clean, force development was achieved mainly by the hip joint during the descending phase and by the ankle joint during the ascending phase.　(3) The joint torque of the ankle in the descending phase, and the joint torque and joint torque power in the ascending phase were increased when the total mechanical energy was increased by the mass factor. The joint torque and joint torque power of the ankle in the descending phase were increased when the total mechanical energy was increased by the velocity factor.　(4)Even if the magnitude of the mechanical energy was the same, the vertical ground reaction force in the descending phase during the velocity-type drop clean was larger than that during the mass-type drop clean. The ground reaction force, joint torque of the hip, and joint torque power of the hip in the ascending phase during the mass-type drop clean were larger than those during the velocity-type drop clean

COMPARISON OF PULL AND CATCH PHASES DURING CLEAN EXERCISESE

The purpose of this study was to identify differences in kinetic characteristics between the performed the PC at 30%, 60%, and 90% of one repetition maximum. Kinetic data were collected from recorded data by using a Vicon motion system and force platforms. In the comparison between the pull and catch phases, the kinetic characteristics of the catch phase were as follows: 1) The peak ground reaction force did not significantly differ according to load. 2) Ankle and knee kinetics showed large values. 3) The force and power in the ankle and knee did not significantly differ between the light load (30%) and heavy load (90%). Therefore, the importance of using PC in training not only for the pull movement but also for the catch movement

DEVELOPMENT OF MULTISTEP DROP JUMP TEST BY USING DIFFERENT DROP HEIGHTS

We used different drop heights to evaluate the drop jump (DJ) test in elite athletes. Male jumpers (n=10) performed the test at 0.3, 0.6, 0.9, and 1.2 m. Jumping motions in the sagittal plane and the ground reaction force were recorded using a high-speed camera and force platform, respectively. The amount of negative work by 3 lower extremity joints increased with increased drop height of the DJ test, mainly at the hip joint. There were different performance patterns on the DJ test and lower extremity power output with an increased drop height according to individual characteristics of elite jumpers, compared with the average pattern. Jump performance was correlated with the DJ index at DJ1.2 and the decreased rate of the index from DJ0.3 to DJ1.2. Thus, to evaluate elite jumpers’ performance, various height ranges including a higher drop height should be used

THE EFFECT OF INCREASING JUMP STEPS ON THE TAKE-OFF LEG IN BOUNDING

The purpose of this study was to clarify the effect of increasing jump steps in bounding in terms of three-dimensional joint kinetics for the take-off leg. Eleven male track and field athletes performed horizontal bounding from the standing posture. Kinematic and kinetic data were recorded using a Vicon T20 system (250 Hz) and force platforms (1,000 Hz). As jump steps increased, the joint kinetics characteristics are as follows: 1) ankle plantar flexion torque and knee extension torque and power increased, but hip extension torque and power did not increase; and 2) hip external torque and power (negative and positive) increased, particularly hip abduction torque and power. Therefore, in bounding initiated from the standing posture, ankle and knee joint kinetics from the sagittal plane and 3dimensional hip joint kinetics increased, particularly on hip adduction-abduction axis

DEVELOPMENT OF A NEW ASSESSMENT METHOD FOR THE REBOUND JUMP TEST

We have proposed a new assessment method using joint kinetics and performance variables in the rebound jump (RJ) test. Twenty-seven male jumpers performed the RJ test. The Quick Motion Analysis System (jointly developed with DKH Inc.) was used to measure joint torque, power, and work of the three lower limb joints in real time, with high precision. High-performance jumpers had high performance values and showed a significantly large amount of joint work in the ankle and hip joints on the RJ test. Comparison of the work of the three lower limb joints confirmed a conflicting relationship between the hip and knee joints and that of the ankles, indicating that this new system is useful for evaluating joint kinetics of the three lower limb joints and may contribute greatly to the assessment of muscle strength and power