著者
湯 海鵬 阿江 通良
出版者
バイオメカニズム学会
雑誌
バイオメカニズム
巻号頁・発行日
vol.12, pp.73-84, 1994
被引用文献数
2

This study was designed to analyze the jumping forehand smash of elite players based on three-dimensional kinematic data, and to gain insight into the basic badminton smash technique. Jumping smashes of four male elite players were filmed with two high-speed cameras operating at 250Hz with exposure times of 1/1500 and 1/1250 s. Nine jumping smashes were selected for the analysis, and were digitized from the take-off of the jump to the end of the swing in the air. Thirty three-dimensional coordinates for the segment endpoints and racket were computed by a Direct Linear Transformation Method. Small reference poles were fixed to the forearms of the swing arms of the subjects to detect the movements of the radio-ulnar joint and wrist joint. The following six joint angle changes were obtained throughout the smash motion. (a) abduction/adduction angle at the shoulder joint; (b) internal rotation/external rotation angle at the shoulder joint; (c) flexion/extension angle at the elbow joint; (d) pronation/supination angle at the radio-ulnar joint; (e) radial flexion/ulnar flexion angle at the wrist joint; (f) palmar flexion/dorsiflexion angle at the wrist joint. The results showed that internal rotation of the shoulder joint, extension of the elbow joint, and pronation of the radio-ulnar joint seemed to contribute to produce great velocities of the racket head, because the three rotations occurred over the greatest range in the shortest time in the six rotations immediately before contact with the shuttle. Preliminary to the three motions were motions in the opposite direction: external rotation of the shoulder, flexion of the elbow, and supination of the forearm were detected. These motions in the opposite direction would be useful to extend the range of the motion in each joint angle. The results also appeared to be related to intrinsic muscle properties, that greater power can be exerted by the stretching-shortening cycle of the muscles. The time of the last joint rotation starting immediately before contact was in the order of decreasing inertia. Times required for the rotation until contact became shorter in order of occurrence. The faster the rotation was, the later it occurred, and the shorter was the rotation time. This kind of chain and continuous movement of different joints, and different freedom with the same joint, may accelerate the racket head efficiently. The averages of elbow angle and racket angle (the angle between the forearm and racket shaft) were 160.0°and 147.0°at contact, respectively the values may be the suitable choices between the contact height and contact speed in practical play.
著者
阿江 通良 湯 海鵬 横井 孝志
出版者
バイオメカニズム学会
雑誌
バイオメカニズム (ISSN:13487116)
巻号頁・発行日
vol.11, pp.23-33, 1992-05-20 (Released:2016-12-05)
被引用文献数
131 170

Inertia properties of the body segments such as segment mass, location of the center of mass, and moment of inertia can be measured and predicted in a number of ingenious approaches. They can be classified into a) direct measurements on cadavers, b) indirect measurements on living subjects, and c) mathematical modelling. However, there is little information upon which complete inertial estimates for Japanese people, especially male and female athletes, can be based. The purposes of this study were to determine the mass, center of mass location, and moments of inertia of the body segments for Japanese male and female athletes using a mathematical modelling approach, and to develop a set of regression equations to estimate inertia properties of body segments using simple anthropometric measurements as predictors. Subjects were 215 male and 80 female athletes belonging to various college sport clubs. Each subject, wearing swimming suit and cap, was stereo-photographed in a standing position. Ten body segments including the upper and lower torso were modelled to be a system of elliptical zones 2cm thick based on Jensen and Yokoi et al. Significant prediction equations based on body height, body weight, and segment lengths were then sought, and some prediction strategies were examined. The results obtained were summarized as follows: 1) Table 2 provides a summary of mass ratios, center of mass location ratios and radius of gyration ratios for males and females. There were many significant differences in body segment parameters between the two sexes. This suggests the need to develop different prediction equations for males and females. 2) Close relationships were noted between segment masses and segment lengths and body weight as predictors for all body segments. Table 5 provides coefficients of multiple regression equations to predict segment masses. 3) No close relationship was noted between independent variables and estimates of the center of mass location. This indicates that the variance in the center of mass location in proportion to the segment length was very small, and that location of centers of mass could be estimated by the mean ratio provided in Table 2. 4) Close relationships were noted between segment moments of inertia and segment lengths (except hand and foot), and body weight as predictors. Tables 6 and 7 provide coefficients of multiple regression equations to predict segment moments of inertia from segment lengths and body weight.
著者
湯 海鵬
出版者
一般社団法人 日本体育学会
雑誌
体育学研究 (ISSN:04846710)
巻号頁・発行日
vol.40, no.3, pp.161-169, 1995-09-10 (Released:2017-09-27)
被引用文献数
1

A technique is presented for determining the angular momentum of the human body about its mass centre for general three-dimensional movements. The three orthogonal components of the angular momentum X, Y, and Z of 15 body segments composed of a transfer term and a local term were computed. The total angular momentum of the whole body was considered to be composed of the sum of the angular momentum of each body segment. The three-dimensional coordinates for determining the angular momentum were computed by a Direct Linear Transformation Method from film data. For calculated individual angular momentum the relative error is estimated to be within 7.2%. The application of the principle of conservation of angular momentum was discussed for the jumping smash of badminton. A large angular momentum was generated by rotation of the smash arm during the airborne phases. The lower limbs react upon the arm with an equal and opposite angular momentum to keep the angular momentum constant. This kind of counter rotation to the smash arm was useful to keep the body balance and reinforce the hitting arm.
著者
湯 海鵬 笹原 英夫 紀 仲秋
出版者
一般社団法人 日本体育学会
雑誌
体育学研究 (ISSN:04846710)
巻号頁・発行日
vol.41, no.5, pp.380-388, 1997

This study was designed to analyze a world class and a Japanese middle-distance runners in women's 800 m finals of the international athletic games based on kinematic data, and to get insight into the basic middle-distance running technique. The performances of Qu yunxia, the world record holder of female 1,500 m and Kumiko Okamoto, the Japan record holder of female 800 m were video-taped with a video camera operating at 60 Hz with exposure time of 1/500 and 1/1000 s. Selected kinematic variables of the center of gravity (C.G), the segment endpoints and rotational energy of the lower limbs were investigated. Some differences of performance were found between Qu and Kumiko in running form. The C.G of Kumiko's up-down motion on vertical direction was about 14% larger; her deceleration in horizontal direction was 48% larger and her up-down motion of C.G of the feet was about 26% than Qu. The larger action of the foot breaking contact with the ground of Kumiko caused a greater loss of horizontal velocity of C.G. The larger flexion of the knee-joint of Kumiko consumes the greater rotational energy than Qu during the recovery phase.
著者
湯 海鵬 阿江 通良 横井 孝志 渋川 侃二
出版者
バイオメカニズム学会
雑誌
バイオメカニズム (ISSN:13487116)
巻号頁・発行日
vol.10, pp.107-118, 1990-09-10 (Released:2016-12-05)

Twisting from a somersault is one of the most used techniques in sports with airborne components such as diving, gymnastics, and so on. The purposes of this study were to investigate the effect of arm swing on the production of aerial twist during somersault and to identify factors affecting the production of the twist. By using a model composed of three rigid bodies, the mechanism of the production of twist from a somersault was confirmed theoretically. Then, quantitative calculation was done based on the model. In the calculation a performer was assumed to swing one arm downward from the symmetrical position with both arms above the head. To validate the model, twisting somersaults of two male skilled gymnasts were filmed and analyzed with 3-dimensional cinematography (DLT method) to compare with the model. The performances were forward twist-somersaults of 1/2, 1 and 3/2 revolutions from a vaulting horse. The factors affecting the generation of twist are discussed based on the results of computer simulation and film data. The results are summarized as follows: 1) An asymmetrical arm swing could generate a twist about the longitudinal axis of the body from a somersault. This arm swing tilted the principal axes of the body away from their original positions. The axis of the angular momentum that was initially established did not change in the airborne phase, but the momentum resolved into two perpendicular components, one about the body's principal longitudinal axis and the another about the body's frontal axis (principal axis). Thus, the somersaulting motion around the frontal axis will continue even though the frontal axis is now tilted from its original position, and in addition the body will begin to twist about its longitudinal axis. 2) The direction of the twist depended upon the initial directions of the somersault and/or arm swing. 3) Large angular velocity of the somersault before the change in the posture and large swing angle of the arm were effective for the generation of twisting. The smaller the moment of inertia about body's longitudinal axis, the larger the twisting that was produced.
著者
湯 海鵬 豊島 進太郎 星川 保 川端 昭夫
出版者
バイオメカニズム学会
雑誌
バイオメカニズム学会誌 (ISSN:02850885)
巻号頁・発行日
vol.27, no.1, pp.37-42, 2003-02-01
被引用文献数
4 4

本研究は,介護作業の中で,最も体に負担の大きいと言われる車椅子への移乗動作を三次元的撮影し,映像データに基づいて介護者の重心の変位,関節角度および身体エネルギーを算出した.理学療法士(PT)と社会福祉学専攻学生の介護動作との比較検討を行い,車椅子への移乗動作の特徴を明らかにした.学生に比べPTの作業時間と作業距離が短かった.身体の姿勢については,PTはできるだけ腰への負担を軽減するために,大腿の筋群を主に用いて被介護者を抱き上げ,腰掛けさせるという動作になっている.このような動作は,身体の上下動が大く,力学的仕事の量も多くなる可能性はあるが,腰の保護と腰痛の予防には有効な動作と考えられる.
著者
阿江 通良 湯 海鵬 横井 孝志
出版者
バイオメカニズム学会
雑誌
バイオメカニズム
巻号頁・発行日
vol.11, pp.23-33, 1992
被引用文献数
67 170

Inertia properties of the body segments such as segment mass, location of the center of mass, and moment of inertia can be measured and predicted in a number of ingenious approaches. They can be classified into a) direct measurements on cadavers, b) indirect measurements on living subjects, and c) mathematical modelling. However, there is little information upon which complete inertial estimates for Japanese people, especially male and female athletes, can be based. The purposes of this study were to determine the mass, center of mass location, and moments of inertia of the body segments for Japanese male and female athletes using a mathematical modelling approach, and to develop a set of regression equations to estimate inertia properties of body segments using simple anthropometric measurements as predictors. Subjects were 215 male and 80 female athletes belonging to various college sport clubs. Each subject, wearing swimming suit and cap, was stereo-photographed in a standing position. Ten body segments including the upper and lower torso were modelled to be a system of elliptical zones 2cm thick based on Jensen and Yokoi et al. Significant prediction equations based on body height, body weight, and segment lengths were then sought, and some prediction strategies were examined. The results obtained were summarized as follows: 1) Table 2 provides a summary of mass ratios, center of mass location ratios and radius of gyration ratios for males and females. There were many significant differences in body segment parameters between the two sexes. This suggests the need to develop different prediction equations for males and females. 2) Close relationships were noted between segment masses and segment lengths and body weight as predictors for all body segments. Table 5 provides coefficients of multiple regression equations to predict segment masses. 3) No close relationship was noted between independent variables and estimates of the center of mass location. This indicates that the variance in the center of mass location in proportion to the segment length was very small, and that location of centers of mass could be estimated by the mean ratio provided in Table 2. 4) Close relationships were noted between segment moments of inertia and segment lengths (except hand and foot), and body weight as predictors. Tables 6 and 7 provide coefficients of multiple regression equations to predict segment moments of inertia from segment lengths and body weight.
著者
湯 海鵬
出版者
バイオメカニズム学会
雑誌
バイオメカニズム
巻号頁・発行日
vol.13, pp.33-40, 1996
被引用文献数
5

The purpose of this study is to evaluate the jumping smash technique in badminton from the viewpoint of conservation of angular momentum. Angular momentum estimates for the whole body were calculated, and the application of the principle of conservation of angular momentum was discussed for the smash motion. A cinematographic technique was used to determine the angular momentum of the human body about its mass center for general three-dimensional movements. The three orthogonal components of the angular momentum of 15 body segments, composed of a transfer term and a local term, were computed. The total angular momentum of the whole body was considered to be composed of the sum of the angular momenta of all body segments. Three-dimensional coordinates for determining the angular momentum were computed using Direct Linear Transformation method from film data. According to the principle of conservation of angular momentum,the smash motion is supported by the cooperation of all body segments. As the jumping smash movement is initiated, the lower limbs acquire some angular momentum on take-off from the ground, and then transmit it to the smashing arm. The torso and the left arm act as intermediaries in transmission of the initial angular momentum between the lower limbs and the swing arm. During the fore swing phase of the arm, a large angular momentum is generated by rapid arm rotation. The lower limbs and the head react to the arm swing with an equal and opposite angular momentum to keep the angular momentum constant. This kind of counter rotation to the smash arm is useful to keep the body balanced and reinforce the hitting arm. Key points in learning the jumping smash technique are to acquire an initial angular momentum on take-off and to create some counter rotation opposite to the swing arm.