著者

中村 康雄 林 豊彦 中村 真里 建道 寿教 信原 克哉 菊入 大輔 桐生 慎哉

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.17, pp.111-121, 2004 (Released:2005-04-15)

参考文献数

17

被引用文献数

1 1 2

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Diagnosis of a shoulder joint injury, particularly one brought about during sports activities, necessitates measurement of its motion accurately and noninvasively. Conventional measurement of shoulder joint movement, however, deals solely with relative movement between humerus and thorax, neglecting other components of the joint. We have focused on 6-DOF measurement of scapula movement relative to the thorax, a subdominant component of shoulder movement. Such motion data, however, cannot easily be obtained by means of a marker-based motion-capture system, due to the skin mobility relative to the skeleton. The objective of this study was to validate measurement accuracy of scapula movement when measuring markers are attached to the skin above the scapula’s bony landmarks.We employed an open MRI (Magnetom Open, Siemens, Germany) to measure the shoulder joint and markers attached to the subject’s skin. Five and three markers were attached to the skin above the scapula and thorax, respectively. Three volunteers (24.0±2.64 years old), who possessed no distinct kinetic dysfunctions in their shoulders, served as subjects, in this preliminary study. Their shoulder movements were sampled at three humeral elevation angles (0°, 90°, 150°) on a frontal plane by open MRI. In order to reduce the skin mobility, the same movements were recorded, using a more accurate method in which the scapula’s markers were relocated into correct positions, determined through the palpation of an experienced physical therapist, at each humeral elevation. In an attempt to validate the skin mobility, we measured the deviation of the markers from the scapula’s bony landmarks during humeral elevation. Next, the scapula movements were estimated by two different methods as follows: the registration technique using bony shape and the least squares method using the set of markers.The results demonstrated that the deviation of the markers could be reduced into less than or equal to 19.0 mm if the markers were remounted at each elevation angle. Using the remounted markers, we verified the estimated error of position and orientation of the scapula to lie within 10.1° and 6.4 mm, respectively.In conclusion, we validated measurement accuracy of the scapula movement using skin markers above the scapula’s bony landmarks. The results showed that a motion-capture system is capable of quantitatively measuring the static shoulder joint movement with the scapula.

著者

西澤 哲 古名 丈人 杉浦 美穂 奥住 秀之 長崎 浩 伊東 元 藤田 祐樹 荻上 真理 上田 裕

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.15, pp.131-140, 2000

被引用文献数

6 4

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Introduction: The gait of older adults is characterized by such gait parameters as slow walking velocity and small range of change in joint angle. The effect of aging on these parameters has been analyzed independently, but the strength of the aging effect on each parameter has not been determined in detail. In the present study, using principal component analysis and analysis of variance, we clarified the strength of the aging effect on gait parameters. Method: The participants were 616 older adults (65 to 91 years old) living in Nangai Village located in northern Japan and 45 young adults (20 to 39 years old). The participants were classified by gender and into five age groups (aged 20 to 39 years, 65 to 69 years, 70 to 74 years, 75 to 79 years, and 80 years or above). They walked on an 11-meter straight walkway at their preferred speeds. The coordinates of markers attached to participants' iliac spines, knees, ankles, toes, and heels were measured using a Vicon-370 system (Oxford Metrics, Oxford, England) during 5 meters near the middle of the walkway. The sampling frequency was 60 Hz. From this three-dimensional data, we calculated 34 representative gait parameters. For these parameters, through principal component analysis and two-way analysis of variance by gender and age groups, we determined aging-related principal components and parameters belonging to each component. Results and Discussion: Through principal component analysis, we detected ten components with over one point of eigen value. After two-way analysis of variance for component score, we classified components according to whether they were age-related or not. The age-related components were the first principal component, with 26.0% of contribution rate. In the first component, stride length, toe height on heel contact, peak extension angle around the hip joint, and magnitude of vertical sway had a high component score; we labeled this component the "stride length" component. The parameters of cadence, single stance time, and magnitude of lateral sway had a high score in the second component (11.0% of contribution rate), which we labeled the "stride duration" component. In the second component, we detected significant gender difference. Components with less than 5% explanation of variance were mainly related to parameters on relative time in one walking cycle, such as timing of maximum knee extension. These results suggest that parameters related to stride length may strongly characterize the gait of older adults. In other words, the gait of older adults may be recognized mainly from their short stride length. The low explanation of variance for timing parameters may suggest that the pattern of kinematic change in one gait cycle is determined strictly, whereas kinematic magnitude is strongly affected by aging.

著者

青木 慶 山崎 信寿

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.14, pp.59-68, 1998

被引用文献数

4 12

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Joint resistance is the passive torque exerted by viscoelastic tissues such as ligaments, capsules, tendons, and muscles around the joint. The main function of joint resistance is restriction of the range of motion. However its positive role for human bipedal walking has not been clarified. In this study, we developed a three-dimensional passive-walking model that can walk on an inclined plane by utilizing gravitational force and joint resistance. By using the model, we can easily observe the influence of joint resistance on walking. The model consists of eleven rigid segments; head, chest, pelvis, upper arms, forearms, thighs, and shank-foot segments. The foot part is modeled with a semicircular plate and can roll over the slope. The joint resistance is approximated with a nonlinear viscoelastic torque element, which can prevent hyperextension and hypertwist of the joint. In order to prevent the knee joint from flexing at heel contact, minimum active torque exerted by the knee extensor during the first stance phase is measured from real walking and approximated as a nonlinear viscoelastic element. If the passive model is placed on a slope, the supporting leg naturally rotates down on the semicircular foot, and the other leg swings forward until it reaches to the slope surface. This motion is repeated to generate walking. Initial conditions of the segment angles, angular velocity, and walking velocity are determined by an optimization so as to minimize the difference in walking pattern between the first and second steps. For evaluation of the model, we calculated the passive walking with actual and artificially restricted knee properties, and these agreed well with actual walking patterns. We simulated passive walking patterns by measured changes in the knee and hip joint resistances and also the range of joint motion. Body proportions were also changed from those of a baby to those of an adult. These simulated results show the following roles and characteristics of the joint resistance by passive tissues: 1) knee joint resistance is important when active torque is applied and at the end of the stance phase, and hip joint resistance acts during only the last stance phase; 2) the supporting leg behaves like a stick during the first half stance phase; 3) elastic energy is charged up in the hip and knee joint by extension action around the ankle joint; 4) the charged energy is released at the swing phase, and the thigh swings forward and shank swings upward; 5) joint motions are not greatly affected by alternation of joint resistance; 6) the walking cycle lengthens if the resistance is weakened or the joint range becomes wider; 7) the strength of joint resistance relates to the body proportions, namely knee joint resistance relates to shank length, and hip joint resistance relates to the inertial moment of the leg; 8) the active torque around a knee joint has less influence in passive walking; 9) the patterns of joint resistance torque are similar to those of muscular torque in real walking; and 10) joint resistance saves walking energy. Consequently, we can understand that joint resistance is adapted to the body proportions and bipedal walking. This fact is useful in restoring fossil humans and their locomotion.

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

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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.

著者

中村 康雄 林 豊彦 中村 真理 中溝 寛之 信原 克哉 加藤 直 飯塚 大輔

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.17, pp.123-132, 2004-08-25

参考文献数

21

被引用文献数

4

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The shoulder and elbow joint of a baseball pitcher are frequently overused by the repetition of throwing. The overuse causes throwing injuries of the shoulder or the elbow joint. To prevent the injuries or find them as soon as possible at an early stage, it is important to understand and evaluate each individual's baseball pitching motion exactly. Therefore, we are developing an analysis system of the baseball pitching motion for clinical use. The pitching motion is classified into four major pitch styles, as follows: overhand, three-quarter, sidearm, and underhand. In the long-term clinical experience in Nobuhara Hospital, we have expected that one of the causes of throwing injuries is related to the pitch styles. A previous paper reported that different pitch styles produced different kinematic and kinetic results of pitching motion analysis (Matsuo, 2000). The difference of pitch styles will influence analysis results of the pitching motion. The classification, however, was performed qualitatively by a person having baseball experience. There is no standard method to classify the pitch styles quantitatively. The pitch styles also have to be classified quantitatively in order to investigate various factors of injuries. The aim of this study was to classify baseball pitchers of various levels into four pitch styles quantitatively and compare the kinematic and kinetic parameters. We measured the pitching motions of the baseball pitchers, using a motion-capture system at 500 Hz. Ages of the 104 subjects of this experiment ranged from 10 to 38 years. We suggested four kinematic parameters in order to classify the pitch styles. The measured pitching motions were then classified into four pitch styles, using multivariate discriminant analysis. The correct answer rate was 89.4%. ANOVA revealed significant differences of the antero-posterior direction of resultant force at the time of ball release among four classified pitch styles. The A-P force vector had high correlation (r=0.82) with horizontal adduction angle of the upper arm. The shear force on the shoulder is one of causes of injury during pitching. To reduce the risk of shoulder injuries, we believe it is necessary to reduce shear forces on the pitcher's shoulder. Our results showed that the sidearm group had 50% lower shear force than the other groups. In conclusion, we suggested four kinematic parameters in order to classify the pitch styles. This result shows that these parameters are appropriate for classifying the pitch styles without relation to age or skill differences. The results of kinematic and kinetic parameters showed the significant differences between four pitch styles. Our next task is to increase the number of subjects, especially sidearm and underhand pitchers.

著者

斎藤 正男 根本 幾

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.2, pp.227-235, 1973

被引用文献数

1

著者

奥 英久 中島 咲哉

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.3, pp.91-96, 1975

著者

大西 謙吾 宮川 浩臣 田島 孝光 斎藤 之男

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.16, pp.155-165, 2002 (Released:2004-09-01)

参考文献数

22

被引用文献数

1

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Demand for fine human function modeling methodology is rising with the popularization of assistive devices. Systems engineering based research that delves into the functional cooperative relationship of the digits, hand, and arm is needed for design of substitutive mechanisms and for their control of the human body. The optimal tool for such research is the design process of a sensor-based robotic hand-arm system. This paper discusses the research issues and our proposed strategy.Our research goal is to develop a sensory-controlled mechanical system for performing versatile human-like prehension. As a design concept, we propose an effective model extracted from functional analysis of the upper limb. The key assumption in categorizing hand behavior is the arm’s driving function. Without proper integration of the two, the hand function can be neither analyzed nor assembled. Our approach uses this assumption as its base; we propose a method for classifying a non-redundant relation to control the dynamic and static use of the artificial upper limb.We began remodeling the degrees of freedom (DOF) of the human hand by identifying the transverse and longitudinal adjustable arch structure in the hand. Our new model is composed of 21 active DOF, which include movement in the palm. We classified movements and postures of the hand and arm with this DOF model located at the end of a seven-DOF arm. We then classified the hand modes as prehensile forms and sustentacular forms.Based on this model and our previous research experience in developing prosthetic upper limbs and anthropomorphic robotic hands, we devised a robotic hand-arm with a total of 24 degrees of freedom. Additionally, a new multitactile sensor has been developed for use on the robotic hands in our laboratory at TDU.For generating control strategy, the behavior of the hand is classified into two divisions. The first is cooperation of the digits and palm, and the second is cooperation of the hand and arm modules. The digit cooperation task is fourfold: formation, transformation, deformation, and hold. A motion planner drives the digit movements from the relation of the hand forms to the task that is proposed.A tactile sensor-based control strategy is presented. The digits are controlled according to the hand modes and the sensory feedback loop, with slippage detection rules. Two strategies are proposed for extending the control for fine manipulation: cooperative slippage sensing of adjacent digits, and slippage prediction applying hand orientation information measured by an inclinometer.The overall objective of our approach is the design of a dexterous control system for a multi-DOF robotic upper limb. This includes discussion of a modeling method for the human upper limb.

著者

宮崎 信次

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

no.17, pp.227-234, 2004-08-25

被引用文献数

2 3

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Several mouse emulator devices are commercially available for patients with high-level cervical cord injury (CCI), muscular dystrophy, and rheumatoid arthritis. These include head mounting pointers which linearly convert the 2-dimensional deviation of head motion to the 2-axis movements of the cursor. Limitations of inherent accuracy of the neck movement controllability restrict the use of these pointers to people with a good range of motion of the trunk and neck. Other mouse emulators utilize a miniature 2-dimensional position sensor which can be activated by mouth, then convert the information to the cursor movements. When the transformation is from 2-dimensional deviations to the position of the cursor, a problem similar to the head mounting pointers arises. When the 2-dimensional deviation is converted to the velocity of the cursor, the problem is solved. However, the currently available devices of this last type have other problems, e.g., overshoot and drift of the cursor during no input. The purpose of this study was to develop an inexpensive mouse emulator device utilizing a mini joystick and analog pressure sensor, and to test its clinical utility in shortterm experiments and middle-term field tests conducted by volunteer monitors. The study also aimed to combine this mouse emulator with commercially available automatic Japanese voice recognition software to enable those who cannot use their fingers for striking keyboards. The new mouse emulator, named "Joystick," converts the 2-dimensional angular deviation nonlinearly, i.e., stepwise parabolically, to the velocity of the cursor, and also provides a dead movement zone and automatic tracking of mechanically neutral position to prevent drift of the cursor during a resting state. A thorough investigation was made to find the automatic voice recognition software best suited for the present purpose. Japan IBM's Via Voice with ATOK15 was selected. Four CCI patients and four healthy subjects participated in the short-term evaluation of the device. The first task was to control the movement of the cursor around the monitor, and to drag and drop certain portions of the text. The second task was to activate Word, define text format, input predetermined text, revise it, and store it as a file with a name. The performance of each subject using the new device was compared with the performance of one C4 CCI subject using a conventional mouth stick and a track ball. The results were promising. Twelve volunteer monitors participated in the mid-term field evaluation of the device, and 6 out of 9 monitors wanted to buy the device after the 2- to 4-week monitor period, which proved that the device is useful for a large part of the subject population at which the present study was aimed.