著者

福永 哲夫

出版者

日本バイオメカニクス学会

雑誌

バイオメカニクス研究 (ISSN:13431706)

巻号頁・発行日

vol.25, pp.8-13, 2021 (Released:2021-08-06)

参考文献数

10

著者

渡邊 貴博 高林 知也 渡部 貴也 久保 雅義

出版者

日本バイオメカニクス学会

雑誌

バイオメカニクス研究 (ISSN:13431706)

巻号頁・発行日

vol.26, pp.52-61, 2022 (Released:2022-09-08)

参考文献数

29

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To prevent chronic ankle instability (CAI) and understand why outcomes vary among patients with a lateral ankle sprain, it is important to examine the differences in movement patterns between copers without recurrent ankle sprain and those who develop CAI. The differences in coordination between both groups are unclear, even though abnormal movements of the rearfoot may affect the forefoot through coupling. Therefore, the purpose of this study was to investigate the coordination between the rearfoot and forefoot of CAI, coper groups. Twelve individuals with CAI, 12 copers, and 12 controls ran on a treadmill at a fixed speed of 2.5 m/s. Kinematic data of the rearfoot and forefoot were measured using a three-dimensional motion analysis system. The coupling angle between the rearfoot and forefoot was calculated using the modified vector coding technique and was classified into four coordination patterns. During early stance, the coper group showed a significantly greater proportion of anti-phase with distal dominancy than the CAI group (p<0.05), and in-phase with distal dominancy approached to decrease than the CAI group (p=0.052). During midstance, the CAI group approached to increase proportion of anti-phase with distal dominancy than the control group (p=0.053). During late stance, the coper group showed a significantly decreased proportion of anti-phase with distal dominancy than the control group (p<0.05). This study may provide in-depth knowledge of motor-behavioral characteristics of coper and CAI.

著者

広野 泰子 藤井 範久

出版者

日本バイオメカニクス学会

雑誌

バイオメカニクス研究 (ISSN:13431706)

巻号頁・発行日

vol.27, pp.9-23, 2023 (Released:2023-12-25)

参考文献数

20

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The purposes of this study were to define the start and end of the transition from curved to straight running, and to investigate the kinematic factors that influence the transition distance. We captured sprinting motion from 40-m before to 15-m after the connection between the curved and straight paths meet in 200-m race. This study detected the transition phase based on the trajectory of the participant that an orthogonal distance between the midpoint of hip joints and a course line. The start of the transition phase was determined as the position of the midpoint of hip joints with the maximum log-likelihood of the standard deviation. Then, the sum of the residual squares of the body trajectory evaluation quantities to the approximate straight line was calculated, and the end was determined as the frame with the maximum log-likelihood of the sum of the residual squares. Our findings revealed a difference of 25.60-m in the transition distance between participants. The transition distance had significant correlations with sprinting motion during the pre-transition phase: a positive correlation with the inward inclination angle of the trunk at right touchdown, a negative correlation with the inward inclination angle of the support leg at right touchdown, and a negative correlation with the inward inclination angle of the trunk in relation to the support leg at left touchdown. In addition, the transition distance exhibited a positive correlation with the step width at left touchdown during the transition phase. These findings suggest that the transition distance would be greater if the moment is induced by altering the direction of the force vector, and conversely, it would be shorter if the moment is generated by changing the point of action (the position of the footprint relative to the body).

著者

鷲野 壮平 村井 昭彦

出版者

日本バイオメカニクス学会

雑誌

バイオメカニクス研究 (ISSN:13431706)

巻号頁・発行日

vol.26, pp.26-31, 2022 (Released:2022-05-23)

参考文献数

11

著者

中島 大貴 森下 義隆 八木 賢太郎 桜井 伸二

出版者

日本バイオメカニクス学会

雑誌

バイオメカニクス研究 (ISSN:13431706)

巻号頁・発行日

vol.24, pp.8-18, 2020 (Released:2020-07-06)

参考文献数

23

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In baseball, the flight distance of batted balls is influenced by not only the batted ball velocity but also the spin. Previous studies reported that balls batted toward the opposite field (right field for the right-handed batter) had greater side spin and curved horizontally. If batters could impart less side spin to the ball, flight distance would be expected to increase because the ball would travel more linearly. The purpose of this study was to investigate how the spin of a batted ball is affected by the vertical bat angle at impact. A pitching machine was used to launch balls toward a fixed bat. The bat was positioned at six different angles under two conditions; the bat's long axis was adjusted horizontally and the bat head was declined 40° lower than the bat grip. The batted ball spins resulting from the batted ball angles were compared between the conditions. There were significant correlations between the horizontal batted ball angle and the side spin of the batted balls in both conditions. There was no significant difference between the slopes of the regression lines for the conditions. In brief, balls batted toward the same direction had similar spin regardless of the conditions. Therefore, it is suggested that the batters should not attempt to control batted ball spin, and increasing their bat swing speed would be still the most important key factor to hit balls long distances toward the various directions.

著者

島田 一志 阿江 通良 藤井 範久

出版者

日本バイオメカニクス学会

雑誌

バイオメカニクス研究 (ISSN:13431706)

巻号頁・発行日

vol.8, no.1, pp.12-26, 2004

被引用文献数

1

著者

川本 竜史 河内 利治 宮城 修 田中 博史 高橋 将

出版者

日本バイオメカニクス学会

雑誌

バイオメカニクス研究 (ISSN:13431706)

巻号頁・発行日

vol.24, pp.1-7, 2020 (Released:2020-07-03)

参考文献数

6

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The purpose of the present case study was to clarify calligraphic skill of a Japanese calligrapher quantitatively. For this purpose, the brushwork of an expert calligrapher was kinematically compared with that of a novice as well as an intermediate. Three subjects (an expert calligrapher, an intermediate, and a novice) participated in the experiment. A motion capture system was used to capture the motion of a brush during writing a kanji on a Japanese writing paper. As results, absolute writing speed tended to fasten and the variability of the vertical displacement of a brush decreased along with the calligraphic skill. The frequency analysis of the horizontal velocity of a brush revealed that a dominant region shifted toward a low-frequency direction in the expert in comparison with the intermediate although their absolute writing speeds were not significantly different. These results suggest that the expert calligrapher could move the brush with rather slow than rapid change of velocity on the horizontal plane accompanying with lowering the vertical brush displacement.

著者

森丘 保典 榎本 靖士 杉田 正明

出版者

日本バイオメカニクス学会

雑誌

バイオメカニクス研究 (ISSN:13431706)

巻号頁・発行日

vol.9, no.4, pp.196-204, 2005

著者

阿部 匡樹 山田 憲政

出版者

日本バイオメカニクス学会

雑誌

バイオメカニクス研究 (ISSN:13431706)

巻号頁・発行日

vol.2, no.2, pp.82-91, 1998

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Approximate Entropy (Ap entropy) was developed as a method to quantify regularity of time-series data. The aim of this study was to examine problems in the application of Ap entropy to human movement data and to distinguish movement patterns by quantifying the regularity of experimental human movement data. The following results were obtained: 1) For a relatively periodic time-series function with a small number of periods,difference in both the number of data points and number of periods affected the Ap entropy value. Thus,for the application of Ap entropy,the number of data points and the number of periods should be made the same. 2) Under the experimental conditions of this study,the change in the Ap entropy value was in accordance with subjective judgment of movement patterns. This indicates that Ap entropy is an effective parameter for quantitatively distinguishing movement patterns in data that differ in time-series regularity.

著者

島田 一志 阿江 通良 藤井 範久 川村 卓 高橋 佳三

出版者

日本バイオメカニクス学会

雑誌

バイオメカニクス研究 (ISSN:13431706)

巻号頁・発行日

vol.8, no.1, pp.12-26, 2004-03-31 (Released:2023-03-11)

参考文献数

27

被引用文献数

31

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The purpose of this study was to analyze the mechanical energy during baseball pitching for 22 varsity baseball players by using three-dimensional motion analysis technique with two force platforms. Joint torque powers, joint force powers, and segment torque powers of the joints were computed using an inverse dynamics approach.In the energy increasing phase of upper torso, a great deal of mechanical energy flowed into the torso. The mechanical energy transferred to the upper torso due to the segment torque power significantly related to the ball velocity at the release (r=0.480, p<0.05). In the late cocking and accelerating phase, great mechanical energy flowed into the distal segment and the ball due to the joint force power were observed at the throwing arm joints. There were significant relationships between the ball velocity at the release and mechanical energy flows due to the elbow and the wrist joint force powers (r=0.775, p<0.001 and r=0.827, p<0.001). These results suggested that the mechanical energy flows to the upper torso in the energy increasing phase of upper torso and to the throwing arm and ball in the late cocking phase are important to increase the ball release velocity.

著者

Yudai KIKUCHI Wataru ITO Tomoya TAKABAYASHI Takanori KIKUMOTO Takahiro WATANABE Anthony Alexis Santos LAIGO Masayoshi KUBO

出版者

Japanese Society of Biomechanics

雑誌

バイオメカニクス研究 (ISSN:13431706)

巻号頁・発行日

vol.27, pp.1-8, 2023 (Released:2023-04-21)

参考文献数

30

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The purpose of this study was to examine the correlation between the passive and dynamic range of hip internal rotation (HIR), one of the risk factors for Jones fracture, foot progression angle (FPA), and lateral deviation of the center of pressure (COP), which is loading index on the fifth metatarsal bone. This crossover study included 12 men with soccer experience. The passive range of HIR (HIR-p) was measured in the prone position. The motion task was crossover cutting in the 45-degree direction and was measured using the 3D motion analysis system and force plate. HIR angle in motion (HIR-m), FPA at initial contact, and the percentage of lateral deviation of the COP within the foot (%LCOP) were calculated from each trajectory. No significant correlation was found between HIR-p and each parameter. %LCOP deviated laterally as peak HIR-m was greater (r = 0.72, p = 0.008). And the greater the FPA, the lower the peak HIR-m (r = -0.83, p = 0.0007). HIR-p may not a factor that increases the mechanical load on the fifth metatarsal bone. Furthermore, increasing the FPA in crossover cutting may alter hip kinematics and result in reduced mechanical loading on the fifth metatarsal bone.

著者

東 章弘 松井 一洋

出版者

日本バイオメカニクス学会

雑誌

バイオメカニクス研究 (ISSN:13431706)

巻号頁・発行日

vol.23, no.4, pp.179-186, 2020-03-25 (Released:2022-03-09)

参考文献数

28

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This study aimed to determine the heart rate and amount of physical activity of two differently skilled athletes while they were competing in amateur radio direction finding (ARDF). Heart rate and GPS data were measured in two athletes during a regional ARDF championship in Japan. Physical activity was estimated using GPS data and altitude derived from a map projection software. Results revealed that compared with the novice, the skilled athlete finished more quickly, covered a shorter distance, and experienced almost no stagnant phases (resting periods). The average heart rate for both athletes exceeded >160 bpm, which is of the same intensity as that found with high-level aerobic training. Additionally, heart rate variations, similar to those observed during intermittent training, were observed in both athletes. Finally, the energy expenditures during the competition greatly exceeded the recommended healthy exercise levels. In conclusion, despite the difference in the skill levels of the athletes, the measured heart rates and estimated physical activity during ARDF were extremely high. However, the difference in skill sets resulted in differences in the total distance covered, total time spent, and movement patterns.

著者

東 洋功 矢内 利政

出版者

日本バイオメカニクス学会

雑誌

バイオメカニクス研究 (ISSN:13431706)

巻号頁・発行日

vol.16, no.3, pp.128-137, 2012-12-10 (Released:2022-04-06)

参考文献数

11

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The purpose of this study was to describe the angular momentum of the runner's body about the center of mass (CM) during the maximum-effort sprinting along a curved runway. Ten male collegiate sprinters were asked to sprint along the 2nd lane on an official 400m track. The performances were recorded with four high speed cameras. The DLT algorithm was used for 3D reconstruction and the angular momentum of the whole body about the CM was calculated. The results showed that the runner’s body possessed throughout the stride cycle an inward-directed component (33.5×10–3±2.8×10–3s–1) of angular momentum and that the head and torso possessed a cranially-directed component (0.4×10–3±0.2×10–3s–1). The antero-posterior component of angular momentum changed its sense from forward- to backward-direction during the right ground contact phase. These results indicate (a) that the runner's head and torso changed its orientation continuously throughout the support- and the airborne-phases to face forward along the curved runway and (b) that the angular impulse exerted on the body during the right ground contact phase changed the direction of the forward somersaulting angular momentum of the whole body possessed primarily by the limbs, so that the runners could maintain the plane of the limbs' rotary motion in the tangential direction to the curved runway.

著者

松浦 由生子

出版者

日本バイオメカニクス学会

雑誌

バイオメカニクス研究 (ISSN:13431706)

巻号頁・発行日

vol.26, pp.32-38, 2022 (Released:2022-05-23)

参考文献数

22

著者

藤井 宏明 藤井 範久

出版者

日本バイオメカニクス学会

雑誌

バイオメカニクス研究 (ISSN:13431706)

巻号頁・発行日

vol.25, pp.14-27, 2021 (Released:2021-10-09)

参考文献数

19

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The purpose of this study was to investigate the body movements to generate handle velocity in the tangential and the radial direction of hammer head during the hammer throw turn. The positive leading distance of handle has the effect of accelerating the hammer head in hammer throw. In addition, the increase and decrease of the leading distance of handle are consistent with the increase and decrease of handle velocity in the radial direction of hammer head. It will be important to clarify the movement of the body for the acquisition of the leading distance of handle by examining the acquisition of the handle velocity in the radial direction by the body movement. Throwing motions of 44 male throwers (throwing record: 80. 50–44. 17 m) participated in the study as subjects. Throwing motions were videotaped on high-speed VTR cameras, and three-dimensional coordinates were calculated using a DLT method. The handle velocity was calculated as the vector products between the anatomical angular velocity vectors of joint and the respective relative displacement vectors from the joint center to handle, by applying a mathematical model. The handle velocity obtained by body movements were projected onto the rotating plane coordinate system. The basic findings were summarized as follows: (1) The handle velocity in the radial direction can be obtained by trunk long-axis rotation, the trunk left lean, the extension of the shoulder joint, the trunk back lean, and translational movement of the body. (2) The handle velocity in the tangential direction can be obtained by the trunk long-axis rotation, trunk twist, horizontal abduction of left shoulder joint and the flexion of shoulder joint.

著者

川副 嘉彦

出版者

日本バイオメカニクス学会

雑誌

バイオメカニクス研究 (ISSN:13431706)

巻号頁・発行日

vol.7, no.2, pp.136-151, 2003

被引用文献数

1

著者

矢内 利政

出版者

日本バイオメカニクス学会

雑誌

バイオメカニクス研究 (ISSN:13431706)

巻号頁・発行日

vol.11, no.3, pp.200-212, 2007

著者

原田 奈名子

出版者

日本バイオメカニクス学会

雑誌

バイオメカニクス研究 (ISSN:13431706)

巻号頁・発行日

vol.10, no.3, pp.203-213, 2006

著者

図子 浩二

出版者

日本バイオメカニクス学会

雑誌

バイオメカニクス研究 (ISSN:13431706)

巻号頁・発行日

vol.7, no.4, pp.303-312, 2003

著者

阿江 通良 永原 隆 大島 雄二

出版者

日本バイオメカニクス学会

雑誌

バイオメカニクス研究 (ISSN:13431706)

巻号頁・発行日

vol.12, no.2, pp.134-140, 2008